Anion-binding polymers and uses thereof

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DESCRIPTION

Anion chelating polymers and their uses.

Ion-selective sorbents have been used in human therapy to correct electrolyte balance disorders in conditions such as hyperphosphatemia, hyperoxaluria, hypercalcemia, and hyperkalemia. Hyperphosphatemia occurs in patients with renal failure, whose kidneys no longer excrete phosphate ions in sufficient quantity to compensate for exogenous dietary phosphate intake. This condition results in a high serum phosphate concentration and a high calcium x phosphate product. Although the etiology has not been fully demonstrated, soft tissue calcification and cardiovascular disease have been attributed to the calcium x phosphate product. Cardiovascular disease is the cause of death in almost half of all dialysis patients.

To control the absorption of phosphate ions in the gastrointestinal (GI) tract and return systemic phosphate levels to normal, salts of aluminum, calcium and, more recently, lanthanum have been prescribed. However, these salts release soluble aluminum and calcium cations into the GI tract, which are then partially absorbed into the bloodstream. Absorption of aluminum can cause serious side effects, such as aluminum bone disease and dementia; high calcium intake leads to hypercalcemia and exposes patients to the risk of coronary calcification.

Some metal-free phosphate chelators have been suggested for use as phosphate chelators, such as, for example, strong base ion exchange materials, Dowex resins and cholestyramine. However, its low chelating capacity requires the use of large doses, which is not well tolerated by patients.

Amine functional polymers have been described as phosphate or oxalate chelators. See, for example, 5,985,938, 5,980,881, 6,180,094, 6,423,754 and PCT publication WO 95/05184. Renagel, a cross-linked polyallylamine resin, is a phosphate sequestrant material introduced on the market as a metal-free phosphate chelator. Renagel's in vitro phosphate chelating capacity is approximately 6 mmol / g in water and 2.5 mmol / g when measured in 100 mM sodium chloride and 20 mM phosphate at neutral pH. The recommended dose for the target patient population is typically between 5 g / day and 15 g / day to keep the phosphate concentration below 6 mg / dl. Some published Phase I clinical trials of Renagel, conducted with healthy volunteers, indicate that 15 g of Renagel reduces the elimination of phosphate through urine from a baseline value of 25 mmol to 17 mmol, eliminating the difference through from faeces in the form of free, polymer-bound phosphate. From these data, the in vivo capacity range can be set to 0.5-1 mmol / g, which is much less than the in vitro capacity of 6 mmol / g measured in saline. Considering only Renagel's in vitro chelating capacity measured in saline, a 15 g dose of phosphate chelator would chelate more than the entire phosphorus content of the average American diet, i.e. 37 mmol / day). The discrepancy between in vitro chelating capacity and the documented low in vivo chelating capacity has a negative impact on the therapeutic benefit of the drug because more resin is needed for serum phosphate to return to safe levels.

This loss of ability of ion exchange resins is not limited to Renagel when used in the complex conditions of the GI tract environment. Although from a toxicological perspective it is generally safe, the high dose and inconvenience associated with the administration of quantities of several grams of resin are arguments in favor of the need to improve the capacity of the resin. By way of example, even in published safety studies on the chelator Renagel, patients have experienced gastrointestinal upset at doses as low as 1.2-2.0 g / day over an 8 week treatment period. Patients who received 5.4 g of Renagel / day had treatment interrupted as a consequence of adverse circumstances such as GI discomfort in 8.9% of cases (Slatapolsky et al., Kidney Int., 55: 299-307, 1999; Chertow et al., Nephrol Dial Transplant 14: 2907-2914, 1999). Accordingly, an improvement in in vivo chelatability resulting in lower and better tolerated doses would represent a welcome improvement in resin-based therapies.

As a result of these considerations, there is still a significant need for safe, high-capacity chelators that are capable of selectively removing ions from the body with a lower dose of the drug and a better patient follow-up profile.

Monitoring by the patient is recognized today as one of the main limiting factors for patients to comply with the K / DOQI recommendations: dose escalation means that patients must take 10 pills of 800 mg per day and even more. Renagel pills are in swallowable tablet form and are administered with minimal fluid, increasing discomfort for ESRD patients who are under fluid restriction. An easier to take pharmaceutical formulation would be desirable: chewable tablets in particular are becoming popular among geriatric and pediatric populations, as well as in treatments requiring a large number of pills; chewable tablets allow for more effective pills and ultimately reduce the number of tablets per dose. As the active substance contained in a chewable tablet is first dispersed under the effects of chewing and saliva before being swallowed, the shape and weight requirements of the tablet are much less stringent than those imposed on tablets. swallowable. However, until now it has not been possible to formulate a hydrogel, such as Renagel, into a chewable tablet, due to the high swelling characteristics of said polymer: Renagel usually swells very quickly to about 10 times its weight in an isotonic solution . This has two major unintended consequences: first, while

ES 2 330 693 T3 remains in the mouth the polymer will swell and provide a very unpleasant sensation (dry mouth, pressure sensation); second, even if the patient overcomes the sensations in the mouth, administering a dilated gel into the esophagus can be dangerous. In addition to this, it is well known that when administered in quantities of several grams, gels that are too dilated cause side effects such as bloating, constipation or diarrhea.

Summary of the invention

In one aspect, the invention provides anion chelating polymers. In some embodiments the invention provides an anion chelating polymer, where the polymer chelates a target anion (eg, phosphate or oxalate), and where the polymer is characterized by at least two of the following attributes: a) a swelling ratio less than about 5; b) a gel pore volume distribution measured in a physiological medium characterized by being a fraction of said pore volume accessible to non-interacting solutes, with a molecular weight greater than approximately twice the MW of the target anion, less than approximately 20% of the weight of the gel; and c) an ion chelation interference relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer. In some embodiments, the expansion ratio is less than about 4, or less than about 3, or less than about 2.8, or less than about 2.7, or less than about 2.6, or less than about 2.5. In some embodiments, the polymer chelates bile acids or citrate with a capacity of less than about 2 mmol / g, or less than about 1 mmol / g, or less than about 0.5 mmol / g, or less than about 0. , 3 mmol / g, or less than about 0.1 mmol / g. In some embodiments, the expansion ratio is measured in isotonic solution and neutral pH. In some embodiments, the polymer comprises amine monomers. In some embodiments, the amine monomers are selected from the group consisting of allylamine, vinylamine, ethyleneimine, 1,3-diaminopropane, and N, N, N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane, 1 , 2,3,4 tetraaminobutane, Formula 1 and Formula 2, where Formula 1 and Formula 2 are the following structures:

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In some embodiments, the invention provides an anion chelating polymer containing cross-linked polyamines, where the polymer is obtained by inverse suspension and where the expansion ratio of the polymer is less than 5.

In some embodiments the invention provides a phosphate chelating polymer, where the polymer is characterized by at least one of the following attributes: a) a swelling ratio less than about 5, preferably less than about 2.5; b) a distribution of the pore volume of the gel measured in a physiological medium characterized by being a fraction of said pore volume accessible to non-interacting solutes, of molecular weight greater than approximately 200, of less than approximately 20% of the weight of the gel ; and c) an ion chelation interference relative to phosphate of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer. In some embodiments, the expansion ratio is less than about 2.8, or less than about 2.7, or less than about 2.6. In some embodiments, the polymer chelates bile acids or citrate with a capacity of less than about 2 mmol / g, or less than about 1 mmol / g, or less than about 0.5 mmol / g, or less than about 0. , 3 mmol / g, or less than about 0.1 mmol / g. In some embodiments, the expansion ratio is measured in isotonic solution and neutral pH.

In some embodiments the invention provides a phosphate chelating polymer, where the polymer is characterized by a swelling ratio less than about 5, preferably less than about 2.8, or less than about 2.7, or less than about 2 , 6, most preferably less than about 2.5, where this ratio is measured in isotonic solution and neutral pH. In some embodiments, the polymer has a mean in vivo phosphate chelating capacity of greater than about 0.5 mol / g. In some embodiments, the polymer is a polyamine polymer, and the chloride content of the polymer is less than about 35 mol% of the amine group content.

In some embodiments the invention provides an anion chelating polymer, where the polymer chelates a target anion (eg, phosphate or oxalate), and where the polymer is characterized by at least two of the following attributes: a) a swelling ratio less than about 5; b) a pore volume distribution of the

ES 2 330 693 T3 gel measured in a physiological medium characterized as being a fraction of said pore volume accessible to non-interacting solutes, with a molecular weight greater than approximately twice the MW of the target anion, less than approximately 20% by weight of the gel; and c) an interference in ion chelation relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer, where the polymer contains one or more amine monomers and one or more crosslinkers and where the polymer is produced by a process where the amine is present in the solvent before crosslinking in an amine ratio: solvent from about 3: 1 to about 1: 3 and the total content of crosslinkers added to the reaction mixture is such that the average number of connections to the amine monomers (NC) is between about 2.05 and about 6, or between about 2.2 and about 4.5. In some embodiments, the polymer is further produced by a process where the target anion is present throughout the crosslinking reaction, for example: a) adding the amine monomer as a free base and adding the target anion in its acid form; b) adding a crosslinker; c) carrying out the crosslinking reaction, and d) washing away the target ion.

In some embodiments the invention provides an anion chelating polymer, where the polymer chelates a target anion (eg, phosphate or oxalate), and where the polymer is characterized by at least two of the following attributes: a) a swelling ratio less than about 5; b) a gel pore volume distribution measured in a physiological medium characterized by being a fraction of said pore volume accessible to non-interacting solutes, with a molecular weight greater than approximately twice the MW of the target anion, less than approximately 20% of the weight of the gel; and c) an interference in ion chelation relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer, where the polymer contains one or more amine monomers and one or more crosslinkers and where the polymer is produced through a process that includes: a) forming a soluble prepolymer by adding the entire amine monomer component and then continuously adding a fraction of the crosslinker to form a syrup; b) emulsifying the syrup in oil; and c) adding the remaining fraction of the crosslinker to form crosslinked granules.

In some embodiments the invention provides an anion chelating polymer, where the polymer chelates a target anion (eg, phosphate or oxalate), and where the polymer is characterized by at least two of the following attributes: a) a swelling ratio less than about 5; b) a gel pore volume distribution measured in a physiological medium characterized by being a fraction of said pore volume accessible to non-interacting solutes, with a molecular weight greater than approximately twice the MW of the target anion, less than approximately 20% of the weight of the gel; and c) an interference in ion chelation relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer, where the polymer contains one or more amine monomers and one or more crosslinkers and wherein the polymer is produced by a process that includes: a) carrying out a first reaction between an amine monomer and a crosslinker to form a gel; then b) reacting the gel with an alkylamino halide, where the alkylamino groups are chemically attached to the gel by substitution of the halide by amine functional gels.

In some embodiments the invention provides a phosphate chelating polymer containing one or more amine monomers and one or more crosslinkers, where the polymer is produced by a process where the total content of crosslinkers added to the reaction mixture is such that the average number of connections to the amine monomers is between 2.2 and 4.5.

In some of these embodiments, the amine monomer is chosen from the group consisting of 1,3-diaminopropane, and N, N, N ', N'-tetrakis (3-aminopropyl) 1,4-diaminobutane, and in which the The crosslinking agent is chosen from the group consisting of 1,3 dichloropropane and epichlorohydrin. In some embodiments, the invention provides an ion chelating polymer comprising N, N, N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane cross-linked by epichlorohydrin, wherein the polymer is produced by a process in where the ratio of the initial concentration of N, N 'tetrakis (3-aminopropyl) 1,4 diaminobutane to water is from about 1: 3 to about 4: 1, or from about 1.5: 1 to about 4: 1.

In some embodiments, the invention provides a phosphate chelating polymer containing monomers of N, N, N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane and epichlorohydrin as a crosslinker, wherein the polymer is produced by a process wherein the total epichlorohydrin crosslinker added to the reaction mixture is from about 200% to about 300% mole, or from about 230% to about 270% mole, or about 250 mol% of the total content of N, N, N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane. In some of these embodiments, the polymer is produced by a process where the ratio of monomers to water in the initial reaction mixture is from about 3: 1 to about 1: 1, or about 1.73. In some embodiments, the polymer is in the form of spherical granules.

In some embodiments the invention provides a phosphate chelating polymer comprising polyallylamine monomers and epichlorohydrin as a crosslinker, wherein the polymer is produced by initially dissolving the polyallylamine monomers in water in a monomer: water ratio of from about 3: 1 to about 1: 3. In some of these embodiments, the epichlorohydrin as the total crosslinking agent added to the reaction mixture is about 10 mol% of the total polyallylamine content.

ES 2 330 693 T3

In some embodiments the invention provides a phosphate chelating polymer comprising a prepolymer comprising 1,3-diaminopropane and a 1,3-dichloropropane crosslinker in a 1: 1 molar ratio, wherein the prepolymer is subsequently crosslinked by epichlorohydrin as crosslinker, and wherein the total epichlorohydrin crosslinker added to the reaction mixture is about 200 mol% of the total prepolymer, and wherein the prepolymer: water ratio in the reaction mixture is from about 1.1: 1 to 1.7: 1.

The invention further provides compositions containing any of the above polymers, where the polymer is in particulate form, and where the polymer particles are covered by an outer shell.

In another aspect, the invention provides pharmaceutical compositions. In one embodiment, the pharmaceutical composition contains a polymer of the invention and a pharmaceutically acceptable excipient. In some embodiments, the composition is a liquid formulation in which the polymer is dispersed in a liquid vehicle of water and appropriate excipients. In some embodiments the invention provides a pharmaceutical composition comprising an anion chelating polymer that chelates a target anion, and one or more acceptable pharmaceutical excipients, where the composition is in the form of chewable or disintegrable tablets in the mouth, and where the polymer has a rate of dilation while passing through the oral cavity and esophagus of less than about 5, or less than about 2.8, or less than about 2.7, or less than about 2.6, or, preferably, less than about 2.5. In some embodiments, the chewable tablet contains a polymer, where the polymer has a transition temperature of greater than about 50 ° C.

In some embodiments, the chewable tablet contains a pharmaceutical excipient chosen from the group consisting of sucrose, mannitol, xylitol, maltodextrin, fructose, sorbitol, and combinations thereof, and is produced through a process in which the polymer is previously formulated with the excipient to form a solid solution. In some embodiments, the target anion of the polymer is phosphate. In some embodiments, the polymer chelates a target ion in vivo with a chelating capacity greater than 0.5 mmol / g. In some embodiments, the anion chelating polymer is greater than about 50% by weight of the tablet. In some embodiments, the tablet is cylindrical in shape, with a diameter of about 22mm and a height of about 4mm, and the anion chelating polymer comprises more than about 1.6g of the total weight of the tablet. In some of the chewable tablets of the invention, the excipients are chosen from the group consisting of sweetening, chelating, lubricating and disintegrating agents. Optionally, the polymer is present as particles less than about 40 µm in mean diameter. In some of these embodiments, the sweetening agent is chosen from the group consisting of sucrose, mannitol, xylitol, maltodextrin, fructose, and sorbitol, and combinations thereof.

In another aspect, the invention provides a method for measuring interference in target ion chelation for an ion chelating polymer that chelates a target ion by: a) adding the ion chelating polymer to a non-interfering buffer containing the target ion and measuring the ability of the polymer to chelate the target ion; b) artificially digesting a standardized food with mammalian GI enzymes and / or aspirating chyme from the upper gastrointestinal tract of mammals that have ingested said standardized food, where the standardized food contains the target ion; c) adding the ion chelating polymer and measuring the chelating capacity thereof from the decrease in the concentration of target ions before and after the incorporation of the target ion; and d) calculating the degree of interference in chelation, as the proportion of decrease in the chelating capacity of the target ion, expressed as a percentage, observed between the measurement of chelation in a non-interfering buffer and in the digested food or in those aspirated ex vivo, at the same equilibrium ion concentration.

In yet another aspect, the invention provides a method for choosing an ion chelating polymer, said monomeric polymer comprising and a crosslinker, wherein said polymer possesses at least one of the characteristics: a) a swelling ratio of less than about 5; b) a gel pore volume distribution measured in a physiological medium characterized by being a fraction of said pore volume accessible to non-interacting solutes, with a molecular weight greater than approximately twice the MW of the target anion, less than approximately 20% of the weight of the gel; and c) an interference in ion chelation relative to the target anion of less than approximately 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer, which includes the steps of: i) varying the following composition and process variables : 1) the ratio of crosslinker to monomer; 2) the ratio of (monomer + crosslinker) to solvent in the reaction medium; 3) the net charge of the polymer at physiological pH and tonicity; and / or 4) the hydrophilic / hydrophobic balance of the polymer backbone; ii) evaluating the swelling capacity, porosity and interference in ion chelation of the resulting polymer; and iii) choosing a polymer that has at least one of said characteristics. In another aspect, the invention provides a method for enhancing the therapeutic properties and / or the suitability for administration and / or the pharmaceutical properties of a polyamine polymer, comprising at least one of the following steps: a) crosslinking said polymer with a crosslinker, so that the average number of connections with a polyamine monomer is between about 2.05 and about 6; and / or b) producing said polymer by a process wherein the polyamine is initially present in water in a polyamine: water ratio of from about 3: 1 to about 1: 3.

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In another aspect, the invention provides a method for preparing an anion chelating polymer that chelates a target anion, comprising combining an amine monomer with a cross-linker by a heterogeneous process, wherein the phosphate chelating polymer is characterized by at least two of the following attributes: a) an expansion ratio less than about 5; b) be less than approximately 20% of the weight of the polymer accessible to non-interacting solutes of molecular weight greater than approximately twice the MW of the target anion, where said percentage is measured in a physiological medium; and c) an ion chelation interference relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer. In some embodiments, the amine monomer is a polyallylamine. In some embodiments, the crosslinker is epichlorohydrin.

In another aspect, the invention provides an anion chelating polymer that chelates a target ion, wherein the polymer is produced by a process comprising crosslinking a polyallylamine by a heterogeneous process, and wherein said polymer is characterized by at least two of the following attributes: a) an expansion ratio less than about 5; b) be less than approximately 20% of the weight of the polymer accessible to non-interacting solutes of molecular weight greater than approximately twice the MW of the target anion, where said percentage is measured in a physiological medium; and c) an ion chelation interference relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer. In one embodiment, the polyallylamine is cross-linked with epichlorohydrin.

In another aspect, the invention provides a method of removing an anion from an animal by administering an effective amount of a polymer of the invention to it. In some embodiments, the polymer is an anion chelating polymer, where the polymer chelates a target anion (eg, phosphate or oxalate), and where the polymer is characterized by at least two of the following attributes: a) a ratio of dilation less than about 5; b) a gel pore volume distribution measured in a physiological medium characterized by being a fraction of said pore volume accessible to non-interacting solutes, with a molecular weight greater than approximately twice the MW of the target anion, less than approximately 20% of the weight of the gel; and c) an ion chelation interference relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer. In some embodiments, the target anion of the polymer is phosphate; In some embodiments, the phosphate is cleared from the gastrointestinal tract; In some embodiments, the mode of administration is orally. In some embodiments, the animal suffers from at least one disease from the group consisting of hyperphosphatemia, hypocalcemia, hyperthyroidism, depressed renal synthesis of calcitrol, tetany due to hypocalcemia, renal failure, ectopic calcification of soft tissues, and ESRD. In some embodiments, the animal is a human.

In some embodiments, the polymer is co-administered with at least one of proton pump inhibitors, calcimimetics, vitamins, and analogs thereof, or phosphate chelators, eg, a phosphate chelator such as aluminum carbonate, calcium carbonate. , calcium acetate, lanthanum carbonate or SEVELAMER hydrochloride.

Inclusion for reference

All publications and patent applications mentioned in this specification are included in the present application by reference, as if each of the individual publications or patent applications were specifically and individually indicated to be included by reference.

Brief description of the illustrations

Figure 1 is a graph illustrating the determination of interference in chelation, comparing an isotherm of the chelation of a target ion by a polymer in a non-interfering buffer, with that of the chelation of a target ion by the polymer in an interfering medium (eg, a gastrointestinal simulant or ex vivo aspirate).

Figure 2 is a graph illustrating non-accessible gel volume in relation to probe solute radius.

Figure 3 is a graph illustrating the determination of chelation interference for a phosphate chelating polymer (EC172A).

Figure 4 is a graph illustrating the determination of chelation interference for a phosphate chelating polymer (RENAGEL).

Figure 5 is a graphical representation of non-accessible volume in relation to probe molecular weight, for non-interacting probes, illustrating the difference between a phosphate chelating polymer of the invention (EC 172A) and a commercially available phosphate chelator. (RENAGEL).

Figure 6 is a graphical representation of non-accessible volume in relation to probe radius, for non-interacting probes, illustrating the difference between a phosphate chelating polymer of the invention (EC 172A) and a commercially available phosphate chelator ( RENAGEL).

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Figure 7 is a graph illustrating the variation in chelating ability with modification of FR-005-144 by chloropropylamine hydrochloride.

The novel features of the invention are set forth particularly in the appended claims. A better understanding of the features and advantages of the invention will be achieved by referring to the following detailed description explaining illustrative embodiments in which use is made of the principles of the invention, and the accompanying drawings thereof.

Detailed description of the invention

introduction

One aspect of the invention provides anion chelating polymeric materials, having one or more of the characteristics of reduced swelling, high ion chelation in vivo, reduced interference from interfering ions, and / or specific porosity. Another aspect of the invention provides pharmaceutical compositions of the anion chelating polymers, wherein the pharmaceutical composition is a chewable tablet or liquid formulation. Yet another aspect of the invention provides methods for preparing or improving anion chelating polymers such that they have one or more of the characteristics of reduced swelling, high ion chelation in vivo, reduced interference from interfering ions, and / or specific porosity. Still another aspect of the invention consists of methods for using the anion chelating polymers of the invention for the treatment of conditions in which an anion is present in excessive amounts. In a preferred embodiment, the anion chelating polymers are used to remove target anions from the GI tract. Examples of target anions that can be removed from the GI tract include, but are not limited to, phosphate and oxalate. In another preferred embodiment, the compositions described in the present application are used in the treatment of hyperphosphatemia, hypocalcemia, hyperparathyroidism, depressed renal synthesis of calcitrol, tetany due to hypocalcemia, renal failure, ectopic calcification of the soft tissues, chronic kidney failure and anabolic metabolism.

II. Polymers

The polymers of the invention are characterized by their ability to chelate ions. Preferably, the polymers of the invention chelate anions, more preferably chelate phosphate and / or oxalate, and most preferably chelate phosphate ions. By way of illustration, anion chelating polymers and especially phosphate chelating polymers will be described; however, it is understood that this description applies equally, with appropriate modifications that will be apparent to those skilled in the art, to all ions and solutes. As used in the present application, a polymer "chelates" an ion, eg, an anion, or is an "ion-chelating" polymer (eg, a "phosphate-chelating" polymer) when attached to the ion, generally though not necessarily, covalently, with a sufficient binding force so that at least a part of the ions remain bound under the in vitro or in vivo conditions in which the polymer is used, and for long enough for the ion to carry out removal from the solution or from the body. A "target" ion is an ion to which the polymer binds and usually refers to the main ion to which the polymer binds, or the ion whose binding to the polymer appears to produce the therapeutic effect of the polymer. A polymer can have more than one target ion. The "chelation" of an anion is more than minimal chelation, ie, at least about 0.01 mmol anion / g polymer, more preferably, at least about 0.05 mmol anion / g polymer, even more preferably, at least about 0.1 mmol anion / g polymer, and most preferably, at least about 0.5 mmol anion / g polymer. The invention provides polymers that are characterized by their selective anion chelation; For example, in some embodiments, the polymers of the invention chelate bile acids with a chelating capacity of less than about 2 mmol / g, preferably less than about 1 mmol / g, more preferably less than about 0.5 mmol / g, even more preferably less than about 0.3 mmol / g, and most preferably less than about 0.1 mmol / g. In some embodiments, the polymers of the invention chelate citrates with a chelating capacity of less than about 2 mmol / g, preferably less than about 1 mmol / g, more preferably less than about 0.5 mmol / g, even more. preferably less than about 0.3 mmol / g, and most preferably less than about 0.1 mmol / g.

A. Characteristics

The polymers of the invention are characterized by one or more of the following attributes: 1) a low expansion ratio; 2) reduced chelation interference under physiological conditions; 3) an appropriate porosity to chelate the target anion and to exclude interfering solutes; 4) in vivo chelating capacity of the target anion, sufficient to be effective in its therapeutic use. In some embodiments, the polymer is an anion chelating polymer (eg, a phosphate and / or oxalate chelating polymer), where the polymer is characterized by at least two of the following attributes: 1) a swelling ratio less than about 5; 2) a gel pore volume distribution measured in a physiological medium characterized as being less than approximately 20% of said pore volume accessible to non-interacting water soluble solutes of molecular weight greater than approximately twice the MW of the target anion ; and 3) an interference in ion chelation relative to the target anion of said polymer of less than about 60% when measured in a gastrointestinal simulant,

ES 2 330 693 T3 with respect to a non-interfering buffer. In some embodiments, the polymer is a phosphate chelating polymer characterized by at least one of the following attributes: 1) a swelling ratio of less than about 5, preferably less than about 2.5; 2) a gel pore volume distribution measured in a physiological environment characterized as being less than about 20% of said pore volume accessible to non-interacting solutes of molecular weight greater than about 200; and 3) an ion chelation interference relative to phosphate of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer. In some embodiments, the phosphate chelating polymer has a swelling ratio of less than about 2.8, or less than about 2.7, or less than about 2.6. A "physiological medium" is a medium that is isotonic and has a neutral pH. In some embodiments the invention provides a phosphate chelating polymer characterized by a swelling ratio, measured in an isotonic medium at a neutral pH, less than about 5, preferably less than about 2.5, optionally with a medium chelating capacity. in vivo phosphate greater than about 0.5 mol / g. In some embodiments, the phosphate chelating polymer has a swelling ratio of less than about 2.8, or less than about 2.7, or less than about 2.6. In some embodiments, the polymers of the invention chelate bile acids with a chelating capacity of less than about 2 mmol / g, preferably less than about 1 mmol / g, more preferably less than about 0.5 mmol / g, still more preferably less than 0.3 mmol / g, and most preferably less than 0.1 mmol / g. In some embodiments, the polymers of the invention chelate citrates with a chelating capacity of less than about 2 mmol / g, preferably less than about 1 mmol / g, more preferably less than about 0.5 mmol / g, even more. preferably less than 0.3 mmol / g, and most preferably less than 0.1 mmol / g. Preferably, the polymers are composed of amine monomers.

Generally, these characteristics are achieved by regulating one or more factors in the production of the polymer.

1) Expansion ratio. The polymers of the invention are cross-linked materials, which means that they do not dissolve in solvents and, at most, swell in solvents.

The rate of dilation in an isotonic physiological buffer, representative of the environment in which it is used, i.e., the gastrointestinal tract, is typically in the range of from about 1.2 to about 100, preferably from about 2 to 20. In some embodiments, the polymers of the invention have an expansion ratio of less than 5, or less than about 4, or less than about 3, or less than about 2.8, or less than about 2.7, or less. than about 2.6, or less than about 2.5. As used in the present application, "expansion ratio" refers to the number of grams of solvent absorbed by one gram of dry cross-linked polymer, when equilibrated in an aqueous medium. When more than one measurement of the expansion is made for a given polymer, the average of the measurements is taken as the expansion ratio.

Expansion ratios can be measured by a variety of methods: the most preferred is the gravimetric method, where the dry polymer is weighed and placed in excess liquid. In some cases, the liquid may be distilled water; preferably, the liquid is an aqueous solution that is isotonic with respect to plasma; most preferably, the liquid is an aqueous solution isotonic with respect to plasma and which is buffered to a neutral pH. For example, a 0.9% NaCl solution can be used. Phosphate buffered saline (PBS) can also be used. The most preferred physiological medium for measurement of dilation is 0.9% NaCl buffered with 30 mM MES to a pH of between about 6.5 and 7.5. The dry polymer (eg, a phosphate chelating polymer) is generally used in fully protonated form with counter ion, eg, chloride. The polymer is soaked in the liquid until equilibrium. The soaked gel is then centrifuged, the supernatant liquid is decanted, and the wet gel is weighed. Care must be taken not to centrifuge at too high a g value to prevent the gel from collapsing. The expansion ratio (RD) is calculated as the difference between the weight of the wet gel and the weight of the dry polymer, divided by the weight of the dry polymer.

Another method is the dye method, where a dye with a very high molecular weight and which is known not to interact with the gel is prepared in the form of an aqueous solution, adding a precise portion of the dry polymer to the solution. The weight ratio of the solution to the polymer is adjusted to be close to and slightly higher than the expected expansion ratio. As the dye has a very high molecular weight (eg, greater than 200,000 g / mol), it does not permeate the gel, while water does, which leads to an increase in the resulting concentration of dye, from which the expansion ratio is determined. An example of a useful dye is fluorescein isothiocyanate modified dextran (ITCF).

The expansion rate of a polymer depends on a number of variables, such as temperature, its ionic strength, the charge density of the polymer, the Flory-Huggins polymer-solvent coefficient, and the crosslinking density. Because the ion chelating polymers of the invention are mostly polymer charged (eg, phosphate ion chelating polyamines are protonated at intestinal pH), their swelling behavior is typically that of polyelectrolyte gels. Although the expansion ratio and pore size are related in some way, that is, a high expansion ratio is normally associated with large pores, there is no theoretical basis that allows to accurately predict the exclusion limit of polyelectrolytic gels.

2) Interference in chelation. In some embodiments, the polymers of the invention have a chelation interference of less than about 70%, more preferably less than about

ES 2 330 693 T3 60%, even more preferably less than about 50%, more preferably less than about 40%, still more preferably less than about 30%, and most preferably less than about 20% when measured in a gastrointestinal (GI) simulant. The phosphate chelating polymers of the invention show chelation interference of less than about 70%, more preferably less than about 60%, still more preferably less than about 50%, more preferably less than about 40%, still more preferably less than about 30%, and most preferably less than about 20% when measured in a GI simulant.

The "degree of chelation interference" or "chelation interference", as used in the present application, refers to the rate of decrease in chelating ability relative to the target ion, expressed as a percentage, observed. between a chelation experiment in a non-interfering buffer and in a gastrointestinal (GI) simulant, at the same equilibrium target anion concentration. A "non-interfering buffer", as used in the present application, refers to a buffer that does not contain one or more solutes that interfere with the chelation of the target ion, and that is buffered to the same pH as the GI simulant. A non-interfering buffer is not necessarily free of all solutes that can interfere, for example, a non-interfering buffer may contain one or both of the ubiquitous gastrointestinal chloride and bicarbonate ions; if present, they may be present at their physiological concentration. An example of a non-interfering buffer is given in Example 1. A "GI simulant" refers in the present application to a preparation that has been designed to simulate the environment of a portion of the GI tract after ingestion of a food, preferably the portion of the GI tract in which the polymer will chelate the most. of the target ion. The GI simulant is typically prepared by the method illustrated in Example

1. The target ion must be present in the GI simulant at the same concentrations used in studies with non-interfering buffers. The degree of interference is easily illustrated by plotting the two corresponding chelation isotherms, that is, that of the GI simulant and in a non-interfering buffer, as shown in Figure 1. An example of determining interference in chelation using a GI simulant is given in Example 1.

It is also possible to measure interference in chelation by comparing the chelation of the target ion in digestive aspirates of subjects, preferably human subjects, with the chelation of the target ion in a non-interfering buffer. If this measurement is made, aspirates should be obtained from a few subjects and the average interference should be taken as interference in the chelation.

It has been found that by carefully choosing the swelling ratio and / or regulating the gel molecular weight exclusion limit, the chelating capacity measured in a competitive mode (i.e., in vivo or in a GI simulant) can be substantially increased by comparison with other gels with the same polymer composition but not optimized in terms of gel porosity.

Unexpectedly, it has been observed that polymers in which the crosslinking and / or crosslinking were increased, have a lower expansion than those with a lower crosslinking and / or crosslinking, although they also have a chelating capacity of the target ions (eg, phosphate ) which was equal to or greater than that of polymers with less cross-linking and / or cross-linking. Not wishing to limit ourselves to theory, the hypothesis is offered that the polymers of the invention exert a sieving effect and chelate only solutes of a specific size in solution and exclude other larger species that would otherwise compete with binding sites in the polymer. Larger molecular weight species include, but are not limited to, inorganic and organic anions, oligopeptides, carbohydrates, bilirubins, lipid micelles, and lipid vesicles.

3) Porosity. It has been found that it is possible to manipulate the process to produce a polymer so that the polymer more strongly exhibits appropriate porosity to chelate the target ions (eg, anions) for which the polymer is designed and to exclude interfering substances.

The pore size distribution of polymer gels is obtained by various methods, such as, for example, mercury porosimetry, nitrogen adsorption, differential scanning calorimetry or solute permeation partitioning techniques. This last technique, the solute permeation partition technique, is the most preferred as it tests the gel in a fully hydrated state identical to one prevailing in the environment in which it is used. The solute permeation technique is an indirect method implemented by Kuga (Kuga SJ, J. of Chromatography, 1986, 206: 449-461) and consists of measuring the gel partition of solutes of known molecular weights. This method consists of three main stages (Kremer et al., Macromolecules, 1994, 27, 2965-73):

- 1. Solutions with dissolved solutes of known concentrations and molecular sizes are brought into contact with the dilated gel. The molecular sizes of the solutes must cover a substantial range.

- 2. Diffusion of solutes in the gel is achieved. Partition of a particular solute depends on both the size of the solute and the pore size distribution of the gel.

- 3. The gel is separated from the surrounding solution and subsequent measurements of the concentration of the solutes in the surrounding solution are made. The reduction of the concentration of each solute relative to the solute concentration of the initial standard is used to calculate the pore size distribution of the gel.

ES 2 330 693 T3

To separate the effects of size exclusion from the effects of molecular attraction / repulsion, solutes are chosen from polymers or oligomers that exhibit little or no interactions with the gel polymer; the most suitable are neutral hydrophilic polymers with a small molecular weight distribution, such as, for example, polyethylene glycol, polyethylene oxide or dextran. Thus, unless otherwise indicated in the present application, the volumes for the exclusion of particular sizes of solutes (also referred to in the present application as "critical permeation volume") refer to volumes measured using solutes that do not exhibit substantially interaction. with the polymer for which measurements are being made.

Following the experimental protocol and the treatment of the data proposed in Kremer et al., Macromolecules, 1994, 27, 2965-73, the pore size distribution can be represented as shown in Figure 2. In Figure 2, the Y axis represents the volume of the swollen gel not accessible to a solute of a given molecular size. In the example shown in the Figure, small molecules smaller than 5 angstroms can permeate through the entire gel. At the other extreme, polymers with a hydrodynamic radius greater than 1000 angstroms are totally excluded from the gel. In that case, the non-accessible volume and the volume of the gel at equilibrium are equal.

The size and molecular weight of the polymers are related by the Mark-Houvink equations that are tabulated for the polymer solutes used as molecular probes. For instance:

Radius (angstroms) = 0.217M⁰·⁴⁹⁸ Dextran

Radius (angstroms) = 0.271M⁰·⁵¹⁷ Polyethylene glycol

Radius (angstroms) = 0.166M⁰·⁵⁷³ Polyethylene oxide

Small molecular weight probes can also be used: Urea: Molecular radius 2.5 angstroms

Ethylene glycol: Molecular radius 2.8 angstroms

Glycerol: Molecular radius 3.1 angstroms

Glucose: Molecular radius 4.4 angstroms

Sucrose: Molecular radius 5.3 angstroms

In this way, the size of the solute can be transformed into molecular weight and vice versa.

The size of the solute is not equal to the size of the pores; if so, this would mean that all the liquid in pores larger than the molecular size of the solute is available as accessible volume: this is incorrect due to the excluded volume effect, also known as the wall effect.

A direct way to characterize the molecular exclusion limit is to: (i) quantify the partition of the molecular probes, (ii) calculate the accessible volume (or weight) as described above, and (iii) normalize it to volume (or the weight) of the total volume (or weight) of the gel.

The desired size exclusion limit is achieved by regulating production variables, such as the crosslinking of the polymer bands and the concentration of the crosslinker (see below). In general, polymers are prepared to have a size exclusion limit that is based on the ion (eg anion) to be chelated and the probable identity of the interfering substances to be excluded, as well as the tolerable amount of expansion for the expected utilization of the polymer. In some embodiments of the invention, the ion chelating polymer has a gel pore volume distribution (critical permeation volume) defined according to the protocol described above and measured in a physiological environment of less than about 60%, less than about 40%, or less than about 20%, of the pore volume of the polymer accessible to non-interacting solutes of molecular weight greater than about 2 times the MW of the target anion. In some embodiments of the invention, the ion chelating polymer exhibits a gel pore volume distribution (critical permeation volume) of less than about 60%, less than about 40%, or less than about 20%. , of the pore volume of the polymer accessible to non-interacting solutes of molecular weight greater than about 1.8 times the MW of the target ion. In some embodiments of the invention, the ion chelating polymer exhibits a gel pore volume distribution (critical permeation volume) of less than about 60%, less than about 40%, or less than about 20%. , of the pore volume of the polymer accessible to non-interacting solutes of molecular weight greater than about 1.6 times the MW of the target ion. In some embodiments of the invention, the ion chelating polymer exhibits a gel pore volume distribution (critical permeation volume) of less than about 60%, less than about 40%, or less than about 20%. , of the volume

ES 2 330 693 T3 polymer pore accessible to non-interacting solutes of molecular weight greater than about 1.4 times the MW of the target ion. In some embodiments of the invention, the ion chelating polymer exhibits a gel pore volume distribution (critical permeation volume) of less than about 60%, less than about 40%, or less than about 20%. , of the pore volume of the polymer accessible to non-interacting solutes of molecular weight greater than about 1.2 times the MW of the target ion. In some embodiments the invention provides a phosphate chelating polymer that exhibits a gel pore volume distribution (critical permeation volume) defined according to the protocol described above and measured in a physiological medium of less than about 60%, less than about 40%, or less than about 20%, of the pore volume of the polymer accessible to non-interacting solutes of molecular weight greater than about 200, more preferably greater than about 180, more preferably greater than about 160, more preferably greater than about 140, and most preferably greater than about 120.

4) Chelation capacity. The polymers described in the present application exhibit ion chelating properties, generally anion chelating properties. In preferred embodiments, the polymers exhibit phosphate chelating properties. The ion chelating capacity (eg, phosphate) is a measure of the amount of a particular ion that an ion chelator can chelate in a given solution. For example, the chelating capabilities of ion chelating polymers can be measured in vitro, eg, in water or saline, or in vivo, eg, from the excretion of ions (eg, phosphate) through the urine, or ex vivo, using for example aspirated fluids, eg, chyme obtained from laboratory animals, patients or volunteers. Measurements can be performed in a solution that contains only the target ion, or at least that does not contain other solutes that compete with the target ions for binding to the polymer. In these cases a non-interfering buffer would be used. Alternatively, measurements can be performed in the presence of other competing solutes, eg, other ions or metabolites, that compete with the target ions for binding to the resin.

The ion chelating capacity of a polymer can be calculated as V * (C_initial-C_eq/ P), expressed in mmol / g, where V is the fixed volume of the solution used, in liters; C_initial is the initial concentration of the target ion in the solution in mM; C_eq is the equilibrium concentration of the target ion in the solution in mM, after adding a weight P, in grams, of the polymer and allowing equilibrium.

In some embodiments, the polymer chelates phosphate. For use in vivo, eg, in the treatment of hyperphosphatemia, it is desirable that the polymer have a high phosphate chelating capacity. In vitro measurements of chelating ability do not necessarily correspond to in vivo chelating capabilities. Therefore, it is useful to define chelating ability in terms of both in vitro and in vivo ability.

The in vitro phosphate chelating ability of the polymers of the invention in a non-interfering buffer can be greater than about 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3 5, 4.0, 5.0, 6.0, 8.0, or 10.0 mmol / g. In some embodiments, the in vitro phosphate chelating ability of the polymers of the invention relative to target ions is greater than about 0.5 mmol / g, preferably greater than about 2.5 mmol / g, even more preferably greater than about 3 mmol / g, even more preferably greater than about 4 mmol / g, and even more preferably greater than about 6 mmol / g. In some embodiments, the phosphate chelating ability can range from about 0.5 mmol / g to about 10 mmol / g, preferably from about 2.5 mmol / g to about 8 mmol / g, and even more preferably from about 3 mmol / g to about 6 mmol / g. Various methods of determining phosphate chelating ability are known in the art. The in vitro phosphate chelating ability of the polymers of the invention is measured as described in Example 1 for the measurement of chelating ability in a non-interfering buffer.

In some embodiments, the average ex vivo phosphate chelating ability of the phosphate chelating polymers of the invention measured in digestive aspirates from human subjects is greater than about 0.2, 0.3, 0.4, 0, 5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.5, 3.0 4 , 0, 5.0 or 6.0 mmol / g. Ex vivo aspirates are obtained as described in Example 1 from normal subjects and chelation is measured as for a non-interfering buffer. Average values ​​have been obtained from about 5-15, or about 1530, or about 30-60 subjects. In some embodiments, measurements have been obtained from 612 subjects.

As used in the present application, "average in vivo phosphate chelating ability" refers to the chelating ability of a polymer as measured in normal human subjects unless otherwise specified, and where the chelation Phosphate content of the polymer is measured by decreased phosphate excretion in urine combined with measurement of phosphate excreted in the faeces as free, polymer-bound phosphate (see below). Average values ​​have been obtained from about 5-15, or about 15-30, or about 30-60 subjects. In some embodiments, measurements have been obtained from 6-12 subjects. In some embodiments, the average in vivo phosphate chelating ability of the polymers of the invention, preferably measured in human subjects, is at least about 0.3 mmol / g, at least about 0.5 mmol / g , at least about 0.8 mmol / g, at least about 1.0 mmol / g, at least about 1.5 mmol / g, at least about 2.0 mmol / g, at least about 3 , 0 mmol / g, at least about 4.0 mmol / g, at least about 5.0 mmol / g or at least about 6.0 mmol / g.

ES 2 330 693 T3

The in vivo chelating ability of the polymer can preferably be determined by measuring the final balance of the target ion (eg, phosphate ion) in mammals, preferably humans: Subjects are given a food with a controlled content of phosphate and chelating polymer and , your phosphate intake and the phosphate excreted in your stool and urine are measured. The study comprises a purification period followed by a period in which the subjects take a daily dose, preferably three times a day, of phosphate chelator, followed by several days without treatment to observe the return to the starting conditions. The drastic reduction in phosphate in the urine usually coincides with the increase in phosphate in the stool. The difference between the moles of phosphate excreted in the faeces and the starting values, divided by the weight of the administered chelator provides a measure of the chelating capacity in vivo. Unless otherwise indicated, the "in vivo" measurements mentioned in the present application use the above protocol. Another method consists in measuring phosphate chelation in vivo and in situ according to the protocol indicated in Example 1, where the mammals are intubated with a double lumen tube to extract the chyme from a certain location in the small intestine. A food with a given phosphate content is supplied together with a known phosphate chelator content and a marker. The marker can be a dye or a nonabsorbable polymer (eg, polyethylene glycol), which is then titrated in the chyme to determine the dilution that occurs throughout the digestion process. The actual chelator concentration is then calculated from the initial concentration in the food and the dilution ratio measured from the marker experiment. The chyme sample is analyzed for total phosphate. The "soluble" phosphate is measured by centrifuging the sample and decanting the supernatant liquid and measuring the phosphate. The "chelated" phosphate is obtained by the difference between total and soluble phosphate. Two series of experiments are carried out with a group of subjects (6-12) who alternately take a placebo (microcrystalline cellulose) or the drug. Chelability is obtained by measuring the increase in "chelated" phosphate between the two sets of experiments, ie, with and without drug administration, and dividing by the concentration of the chelator. The calculation can be done either by subjects or by groups.

B. Preparation of Polymers

The polymers of the invention are prepared by methods known to those skilled in the art; for example: ion chelating monomers, or their precursors, can be copolymerized in the presence of a crosslinker; a preformed ion chelating polymer is subsequently crosslinked by a chemical reaction or irradiation; or a polymer precursor is first cross-linked and then reacted to form ion chelating functional groups on the polymer.

Polymers are made by direct or reverse suspension, emulsion or precipitation techniques, aerosol polymerization, or by using bulk polymerization / crosslinking methods and size reduction processes such as extrusion and grinding. The processes can be carried out as batch, semi-continuous or continuous processes.

The dilation ratio, chelation interference, chelation capacity, and PM exclusion limit are affected by at least the following composition and process variables:

1. Concentration of chemical crosslinks in polymer chains.

2. The ratio of (monomer + crosslinking) to solvent in the crosslinking reaction.

3. The net charge of the polymer (under the conditions of physiological pH and tonicity of the medium in which it will be used).

Four. The hydrophilic / hydrophobic balance of the polymer backbone.

5. The presence or absence of a shell and core structure, where the shell component restricts the extent of expansion of the core material.

In the following, preferred operating ranges for composition and process variables are exemplified with crosslinked polyamine materials with phosphate chelating properties. It will be understood that these are exemplary conditions only, and that the methods described in the present application can be used in the selection and production of polymers capable of chelating a wide range of solutes, as will be apparent to one of ordinary skill in the art. .

1) Concentration of chemical crosslinks of polymer chains. The concentration of chemical crosslinks is an important characteristic that controls the swelling properties and pore distribution of the polymer. A convenient way to describe the polymers of the invention is to define a repeating amine unit and its average number of connections to the rest of the polymer. "A" is defined as the repeating amine unit and "NC" is the average number of connections starting from A; NC can be 2, 3,4 and greater. To form an insoluble gel, NC must generally be greater than 2.

ES 2 330 693 T3

The NC values ​​can then be transformed into stoichiometric ratios of amine to crosslinker using the following equations:

For low molecular weight monomers, eg, N, N, N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane, NC = B * Fb / A, where B is the number of moles of the crosslinker, Fb is the number of groups in B that react with A to establish a covalent bond, and A is the number of moles of amine.

When the amine material is of high molecular weight and comes from the polymerization of an amine monomer, such as, for example, vinylamine, polyethyleneimine, polyvinylamine or polyallylamine, the expression is modified to take into account the two connections that link the repeats of the monomer with the backbone of the polymer. NC then becomes: NC = (2 * A + B * Fb) / A.

On the contrary, the molar ratio of crosslinking agent to amine can be calculated from the desired NC value by regulating the previous equations:

Low molecular weight amine:

B / A = NC * Fb

High molecular weight amine:

B / A = (NC-2) * Fb

The table below shows some examples of conversion between NC and the actual ratio of crosslinker to amine, where the amine is either a high molecular weight material or a small molecule, and where the crosslinker material is both di and tri functional.

<td>Atina Material</td><td>Typhus of Anina</td><td>Criss-cross</td><td>Fb</td><td>NC Desired</td><td>Molar Ratio B / A</td><td>Equations Used</td>

<td>Polyallylamine</td><td>PMAto</td><td>Epichlorohydrin</td><td> 2</td><td> 22</td><td> 0.10</td><td>b</td>

<td>Polyvinylamine</td><td>PMAto</td><td>1 3 D-chloropnopane</td><td> 2</td><td> 25</td><td> 0 25</td><td>b</td>

<td>Polyethyleneimine</td><td>PMAto</td><td>N-tris (2-chloroethyl) amine</td><td> 3</td><td> 22</td><td> 0.07</td><td>b</td>

<td>1.3 Diaminopropan or</td><td>Atina PM Low</td><td>1 3 tJchloropropane</td><td> 2</td><td> 2</td><td> 1.00</td><td>to</td>

<td>NU.N'K-tetrakis (3-aminopnopil) 1,4 diaminobutane</td><td>Atina PM Low</td><td>Epichlorohydrin</td><td> 2</td><td> 4</td><td> 2,00</td><td>to</td>

<td>N, NNN'-tetrakis (3-aminopropyl) 1.4 diaminobutane</td><td>Atina PM Low</td><td>N-tris (2-chloro-ethyl) amine</td><td> 3</td><td> 4</td><td> 1,33</td><td>to</td>

(a): B / A = NC * Fb (b): B / A = (NC-2) / Fb

Surprisingly, it has been observed that the chelation selectivity, which reflects the efficacy in vivo, went through an optimum with respect to NC: in the lower range of NC values ​​the material tended to expand considerably and consequently showed a great interference in the chelation in a GI simulant. However, in the upper range, the material had a substantially low intrinsic chelating ability, which obviously reduced the overall in vivo performance. Optimal NC values ​​were found to be between 2.05 and 5, depending on the amine / crosslinker systems.

However, the optimal range to provide the desired combination of characteristics in the final polymer depends on the specific monomer and crosslinker used, as well as other conditions employed in the production process, such as the initial concentration of the monomer in the reaction medium and is a matter of routine experimentation.

In some embodiments, the ratio of the crosslinking agent to the total amine groups of the monomers in the polymer is greater than 50 mol%, 60 mol%, 70 mol%, 80 mol% or 90 mol%.

In some embodiments of the invention that provide a phosphate chelating polymer containing one or more low molecular weight amine monomers and one or more crosslinkers, NC is greater than about 2, or greater than about 3, or greater than about Four. In some embodiments, the polymers are constructed from monomers of N, N, N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane (low MW monomers) cross-linked by epichlorohydrin (Fb = 2), where B / A is from about 2.0 (mol / mol) to about 3.0 (mol / mol) (i.e., NC is from about 4 to about 6), or from about 2.3 (mol / mol) up to about 2.7 (mol / mol) (i.e. NC is from about 4.6 to about 5.4), or about 2.5 (mol / mol) (ie, NC is about 5.0). In some

ES 2 330 693 T3 embodiments, the polymers are constructed from monomers of N, N, N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane cross-linked by epichlorohydrin, where the initial ratio of the monomer to the water is from about 3: 1 w / w to 1: 3 w / w, or from about 1.5: 1 to about 2: 1 w / w, or about 1: 1, or about 3: 1, where B / A is from about 2.0 (mol / mol) to about 3.0 (mol / mol) (i.e. NC is from about 4 to about 6), or from about 2.3 (mol / mol) to about 2.7 (mol / mol) (i.e., NC is from about 4.6 to about 5.4), or about 2.5 (mol / mol) (ie, NC is about 5.0).

2) The ratio of (monomer + crosslinker) to solvent in the crosslinking reaction. High ratios of (monomer + crosslinker) to solvent favor highly crosslinked materials when all other conditions are held constant. For example, when a high molecular weight amine is used and when the chain length and the concentration of the polymer are sufficiently large, entanglements are produced in the chain that generate many cross-linking nodes once the structure is chemically cross-linked. More generally, for both low and high molecular weight amines, a high ratio of (monomer + crosslinker) to solvent tends to minimize the amplitude of side reactions that result in gel defects (eg, crosslinking in the interior of the chain giving rise to cyclic structures, and incomplete crosslinking reaction which gives rise to free ends).

This condition is mainly determined by the concentrations in the reaction medium of both the monomer (eg, amine) and the crosslinking agent. In some embodiments of the invention the concentration of the monomer and the crosslinker in the reaction medium is greater than about 20% by weight, preferably greater than 40% by weight, more preferably greater than 60% by weight. In some embodiments, a ratio (monomer + crosslinker): solvent (eg, water) of between about 3: 1 to about 1: 3 (w / w) is used. In some embodiments, a ratio (monomer + crosslinker): solvent (eg, water) of from about 3: 1 to about 1: 1 (w / w) is used. In some embodiments, a ratio (monomer + crosslinker): solvent (eg, water) of about 3: 1, or about 2.5: 1, or about 2.0: 1, or about 1.5: 1, or about 1: 1 (w / w). The crosslinker can be added at various times depending on the polymerization method. In some embodiments, an initial monomer: solvent ratio (before addition of the crosslinker) is from about 4: 1 to about 1: 1, or from about 3: 1 to about 1: 1; the crosslinking agent is then added to represent from approximately 100 mol% to approximately 400 mol% of the initial monomer content, or between approximately 200 mol% to approximately 300 mol% of the initial monomer content. In some embodiments, the monomers are N, N, N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane monomers and the crosslinking agent is epichlorohydrin and the initial monomer: water ratio is from about 4: 1 to 1: 1, or from about 3: 1 to about 1: 1, or about 1.7, or about 1.73; and the crosslinker is added at from about 200 mole% to about 300 mole% of the monomer content, or about 230 mole% to about 270 mole%, or about 250 mole%.

In some embodiments, eg, embodiments in which the monomer is a polyallylamine, the amount of monomer is much greater than the amount of crosslinking agent (eg, 10 times more crosslinking in molar terms and even more in terms of weight) , and the above ratios can be expressed as monomer: solvent ratios, ignoring the crosslinker. In some embodiments, the monomer (eg, polyallylamine) is present in a monomer: solvent ratio of from about 3: 1 to about 1: 3. In some embodiments, the monomer is polyallylamine and the crosslinker is epichlorohydrin, where the polyallylamine is present in a monomer: water ratio of about 3: 1 to about 1: 3 and the epichlorohydrin is added to the reaction mixture up to about 10 % mol of the total content of polyallylamine.

When possible, solvent-free processes are even more preferred: in one embodiment the amine and crosslinker are rapidly mixed and subsequently fully dispersed in a continuous phase, eg water. The crosslinking reaction takes place within the dispersed droplets and is obtained in the form of granules.

3) The net charge of the polymer (under the conditions of physiological pH and tonicity). The net charge of the polymer is determined by the molar content of the ion chelation, its intrinsic charge and the degree of ionization at physiological pH. The charge density is preferably in the range of 3 to 20 mmol / g, preferably 6 to 15 mmol / g.

4) The hydrophilic / hydrophobic balance of the polymer backbone. The hydrophilic / hydrophobic balance of the polymer allows relatively independent control of the chemical crosslinking density and the expansion ratio. The expansion ratio is very sensitive to the parameter ^ + ,, of interaction between the polymer and the solvent as described in the Flory-Huggings protocol (Flory PJ. "Principles of Polymer Chemistry", Cornell Ithaca Pub., 1953). Increasing values ​​of ^ + ,, up to 0.4 and above give rise to poor solvent conditions for the polymer, which causes the interaction between the monomer and the solvent (water) to be minimized and consequently to expand much less. This can be achieved by incorporating hydrophobic portions into the gel, such as, for example, long chain hydrophobic (poly) aromatic substituents, or fluorinated groups. When this strategy is chosen to control the extent of the expansion and consequently the exclusion limit of the gels, the level of hydrophobic monomers and crosslinking agents is between approximately 0.5 mol% to approximately 50 mol%, preferably between approximately 20 and 50%. %.

ES 2 330 693 T3

In preferred methods the absolute hydrophobicity is quantified by the absolute difference in the log P of the monomers. Quantitatively, the hydrophobic / hydrophilic nature of monomers can be determined according to the log P of the specific monomers, which is sometimes designated as the octanol-water partition coefficient. The log P values ​​are well known and are determined according to a standard test that determines the monomer concentration in a separate water / 1-octanol mixture. In particular, computer programs are available commercially, as well as on the Internet, that will estimate log P values ​​for specific monomers. In this application, some of the log P values ​​were estimated through the website http://esc.syrres.com/interkow/kowdemo.htm which provides an estimate of the log P value for molecules simply by inserting the CAS record number or a chemical notation. Hydrophobic monomers will typically have a log P value greater than zero and hydrophilic monomers will typically have a log P value close to or below zero. Generally the log P of the hydrophobic monomers for the purposes of this invention should be at least about 0.5, more preferably at least about 0.75, even more preferably at least about 1.0, still more preferably at least about 1, 5 and most preferably at least about 2.

5) The presence of a shell and core structure, where the shell component restricts the amplitude of expansion of the core material. Gel particles with shell and core morphologies are useful in the context of the invention: the shell material can limit the expansion and therefore limit the exclusion limit, imposing a mechanical resistance to the resulting expansion pressure. of the core material, which would otherwise expand to a much greater extent. The cover material can have the same composition as that of the core, but with a higher crosslink density. The design of such shell and core materials and a method for preparing them can be found in US Patent Application No. 10 / 814,789.

The cover material can be chemically attached to the core material or physically coated. In the first case, the shell can be deposited on the core component through chemical means, for example: by chemical grafting of the shell polymer onto the core using living polymerization from active sites anchored on the core polymer. ; by interfacial reaction, that is, a chemical reaction localized on the surface of the core particle, such as, for example, interfacial polycondensation; and using block copolymers as suspending agents throughout core particle synthesis.

Interfacial reaction and the use of block polymers are preferred techniques when using chemical methods. In the course of the interfacial reaction, typically, the periphery of the core particle is chemically modified by reacting small molecules or macromolecules on the surface of the core. For example, an ion chelating core particle containing an amine is reacted with a polymer containing groups that react with the amine, such as epoxy, isocyanate, activated esters, or halide groups, to form a cross-linked shell around the amine. nucleus.

In another embodiment, the shell is first prepared using interfacial polycondensation or solvent coacervation to produce capsules. The interior of the capsule is then filled with core-forming precursors to form the core within the shell capsule.

In some embodiments, applying the block copolymer approach, an amphiphilic block copolymer can be used as a suspending agent to form the core particle in a direct or reverse suspension particle formation process. When a water-in-oil reverse suspension process is used, in that case the block copolymer comprises a first block soluble in the continuous oil phase and another hydrophilic block contains functional groups that can react with the core polymer. When added to the aqueous phase, along with the core-forming precursor, and the oil phase, the block copolymer encounters the water-in-oil interface and acts as a suspending agent. The hydrophilic block reacts with the core material, or reacts together with the precursors that make up the core. After separating the particles from the oil phase, the block copolymers form a thin shell covalently bonded to the surface of the core. The chemical nature and length of the blocks can be varied to modify the shell permeation characteristics for the solutes of interest.

When the shell material is physically adsorbed onto the core material, well known microencapsulation techniques can be used, such as, for example, solvent coacervation processes, a multi-emulsion or fluidized bed diffusion coater. A preferred method of microencapsulation is the fluidized bed diffusion coater in the Wurster configuration. In yet another embodiment, the shell material acts only temporarily to delay the dilation of the core particle while it is in the mouth and esophagus, and optionally disintegrate it in the stomach or duodenum. Therefore, the cover is chosen to prevent the transport of water into the core particle, by creating a layer of high hydrophobicity and very low permeability to liquid water.

Thus, in one aspect the invention provides a method for choosing an ion chelating polymer, where the polymer contains a monomer and a crosslinker, and where the polymer possesses at least one of the characteristics a) a swelling ratio less than about 5; b) a gel pore volume distribution measured in a physiological medium characterized by being a fraction of said pore volume accessible to non-interacting solutes, with a molecular weight greater than approximately twice the MW of the target anion, less than approximately 20% of the weight of the gel; and c) an ion chelation interference relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer by:

ES 2 330 693 T3

i) vary the following composition and process variables:

1) the ratio of crosslinker to monomer;

2) the ratio of (monomer + crosslinker) to solvent in the reaction medium;

3) the net charge of the polymer under conditions of physiological pH and tonicity; me

4) the hydrophilic / hydrophobic balance of the polymer backbone;

ii) evaluating the swelling capacity, porosity and interference in ion chelation of the resulting polymer; and iii) choosing a polymer that has at least one of the above characteristics.

In another aspect, the invention provides a method for improving the therapeutic properties and / or the suitability for administration and / or the pharmaceutical properties of a polyamine polymer, comprising at least one of the following steps: a) crosslinking said polymer with a crosslinker, so that the average number of connections to the polyamine monomer is between about 2.05 and about 6; and / or b) producing said polymer by a process wherein the polyamine is initially present in water in a polyamine: water ratio of from about 3: 1 to about 1: 3.

C. Monomers

Any suitable monomers and crosslinkers can be used in the polymers of the invention. When the polymer chelates phosphate or oxalate, the polymer usually comprises a polyamine and a crosslinker. Polyamines include amine functional monomers, such as, for example, those described in U.S. Patent Nos. 5,496,545, 5,667,775, 6,509,013, 6,132,706, and 5,968,499, and in Patent Applications United States No. 10 / 806,495 and 10 / 701,385. These patents and patent applications are included herein in their entirety for reference.

In some embodiments the invention provides ion chelating polymers containing crosslinked amine moieties. In some of these embodiments, the polymers are characterized by one or more of the properties of low swelling, high in vivo ion chelation, low interference from interfering ions, and / or specific porosity. Polymers, including homopolymers and copolymers, with crosslinked amine repeating units are referred to in the present application as crosslinked amine polymers. Repeating amine units in the polymer can be separated by equal or different lengths of repeating (or intervening) linker units. In some embodiments, the polymers are made up of repeating units of an amine plus an intervening linking unit. In other embodiments the multiple amine units are separated by one or more binding units.

A useful monomer in the polymers of the invention comprises an amine of formula I

<img file="ES2330693T3_D0002.tif" />

where each n, independently, is equal to or greater than 3; m is equal to or greater than 1; and each R₁, independently, is H or optionally substituted alkyl or aryl, or is attached to an R₁ proximate to form an optionally substituted alicyclic, aromatic, or heterocyclic group. In one embodiment, the invention is a cross-linked amine polymer comprising an amine of Formula I, as described, where the amine is cross-linked with a cross-linking agent.

ES 2 330 693 T3

Preferred amines of formula I include:

<img file="ES2330693T3_D0003.tif" />

In one aspect, the invention provides methods for treating an animal, including humans, using the polymers of the invention. One embodiment of this aspect is a method of removing phosphate from the gastrointestinal tract of an animal by administering an effective amount of a cross-linked amine polymer, wherein said polymer comprises an amine of formula I.

A second monomer useful in the polymers of the invention comprises an amine of formula II

<img file="ES2330693T3_D0004.tif" />

where p is 1, 2, 3, or 4; each R₁, independently is H or optionally substituted alkyl or aryl or is attached to an R₁ proximate to form an optionally substituted alicyclic, aromatic, or heterocyclic group; R₂ and R₃, independently are, H or optionally substituted alkyl or aryl, with the proviso that when p = 1, neither of them, nor R₂ nor R₃, are H and when p = 2, 3 or 4, R₂ and R₃ are H, alkyl, or -C (R₁)₂-R₄-N (R₁ )₂, where R₄ a bond or methylene; furthermore, in some embodiments, the amines of formula II include amines in which p is greater than 4. In various embodiments p may be greater than 8, greater than 12, greater than 16, or greater than 20. In others embodiments p can be less than 25, less than 20, less than 15 or less than 10. In one embodiment, the invention is a cross-linked amine polymer comprising an amine of formula II, as described, where the amine is cross-linked with a cross-linking agent.

ES 2 330 693 T3

Preferred amines of formula II include:

<img file="ES2330693T3_D0005.tif" />

One embodiment of the invention is a method of removing phosphate from the gastrointestinal tract of an animal by administering an effective amount of a cross-linked amine polymer, wherein said polymer comprises an amine of formula II.

A third monomer useful in the polymers of the invention comprises an amine of formula III wherein q is 0, 1 or 2; and each R₁, independently is H or optionally substituted alkyl or aryl or is attached to an R₁ proximate to form an optionally substituted alicyclic, aromatic, or heterocyclic group. In one embodiment, the invention is a cross-linked amine polymer comprising an amine of formula III, as described, where the amine is cross-linked with a cross-linking agent.

Preferred amines of formula III include:

<img file="ES2330693T3_D0006.tif" />

<img file="ES2330693T3_D0007.tif" />

ES 2 330 693 T3

An embodiment of the invention is a method for removing phosphate from the gastrointestinal tract of an animal by administering an effective amount of a cross-linked amine polymer, wherein said polymer comprises an amine of formula III.

A fourth monomer useful in the polymers of the invention comprises an amine of formula IV

<img file="ES2330693T3_D0008.tif" />

where each n, independently, is equal to or greater than 3; each r, independently is 0, 1 or 2; and each R1, independently, is H or optionally substituted alkyl or aryl, or is attached to a proximal R1 to form an optionally substituted alicyclic, aromatic, or heterocyclic group. In one embodiment, the invention is a cross-linked amine polymer comprising an amine of formula IV as described, where the amine is cross-linked with a cross-linking agent.

A preferred amine of formula IV includes:

<img file="ES2330693T3_D0009.tif" />

An embodiment of the invention is a method of removing phosphate from the gastrointestinal tract of an animal by administering an effective amount of a cross-linked amine polymer, wherein said polymer comprises an amine of formula IV.

A fifth monomer useful in the polymers of the invention comprises an amine of formula V

<img file="ES2330693T3_D0010.tif" />

where each n, independently, is equal to or greater than 3; each r, independently is 0, 1 or 2; and each R1, independently, is H or optionally substituted alkyl or aryl, or is linked to a proximal R1 to form an optionally substituted alicyclic, aromatic, or heterocyclic group. In one embodiment, the invention is a cross-linked amine polymer comprising an amine of formula V, as described, where the amine is cross-linked with a cross-linking agent.

ES 2 330 693 T3

Preferred amines of formula V include:

<img file="ES2330693T3_D0011.tif" />

An embodiment of the invention is a method for removing phosphate from the gastrointestinal tract of an animal by administering an effective amount of a cross-linked amine polymer, wherein said polymer comprises an amine of formula V.

A sixth monomer useful in the polymers of the invention comprises an amine of formula VI

<img file="ES2330693T3_D0012.tif" />

in which each m, independently, is equal to or greater than 3. In one embodiment, the invention is a cross-linked amine polymer comprising an amine of formula VI, as described, where the amine is cross-linked with an agent crosslinking agent.

An embodiment of the invention is a method for removing phosphate from the gastrointestinal tract of an animal by administering an effective amount of a cross-linked amine polymer, wherein said polymer comprises an amine of formula VI.

The amines represented by general formulas I-VI can be synthesized by methods well known in the art. These synthesis techniques include catalytic conversion from alcohols, reductive amination of carbonyl compounds, Michael additions, and hydrogenation of nitriles (see, for example, Karsten Eller et al., Ullmann's Encyclopedia of Industrial Chemistry 2002 by Willey-VCH Verlag GmbH &amp; Co. KGaA). Various small amine monomers and / or amines plus intervening linking units also exist commercially.

In one embodiment, an amine useful in the present invention, tetramethylene tetramine, represented below, is synthesized by catalytic hydrogenation of commercially available diaminomaleonitrile (DAMN):

<img file="ES2330693T3_D0013.tif" />

Catalyst

H₂ nh₂ nh₂ nh₂ nh₂

The amines that can be used in the present invention are not limited to, but are typically small amines that serve as monomers or parts of monomer units for polymerization reactions. In some embodiments, the monomers are low molecular weight monomers, that is, monomers with a molecular weight of less than 200 g / mol.

In some embodiments of the invention, the monomers are non-polymeric, eg, non-polymeric amines. As used herein, a "polymer" comprises a relatively high molecular weight molecule whose structure essentially comprises multiple repeats of units derived, actually or conceptually, from relatively low molecular weight molecules.

Some examples of suitable amines for the synthesis of the polymers of the present invention include, but are not limited to, the amines shown in Table 1.

ES 2 330 693 T3

TABLE I

<td>Label</td><td>Guy</td><td>A ,, Structure · .-%&gt;, ·</td><td>PM gdnol</td>

<td>B-SM-20T «A</td><td>Tetramine</td><td>1 .A</td><td> 316.54</td>

<td>B-SM-22OA</td><td>□ amine</td><td></td><td> 61.1</td>

<td>8-SM-23- GIVES</td><td>□ amine</td><td>h₂n - ^ - ^ /^NH2</td><td> 68.15</td>

<td>B-SM-24- GIVES</td><td>□ amine</td><td>rX Η, Ν NH,</td><td> 74,13</td>

<td>GIVES</td><td>□ amine</td><td>H, H NH,</td><td> 83.15</td>

<td>B-SM-26DA</td><td>□ amine</td><td></td><td> 128221</td>

<td>B-SM-27DA</td><td>□ amine</td><td>\ -? NH,</td><td> 114.18</td>

<td>B-SM-28TA</td><td>Triamine</td><td>----—------ CsssJ 2HQ NH.</td><td> 196.06</td>

<td>B-SM-29TA</td><td>Tri amine</td><td>HA ^ yNH, ΗγΗ NH,</td><td> 125,13</td>

<td>3-SM-31- GIVES</td><td>□ amine</td><td>ÍHO</td><td> 184.07</td>

<td>B-SM-32OA</td><td>□ amine '</td><td>TO NH, W,</td><td> 136.2</td>

Additional amine monomers that can be used in polymers of the invention include portions of vicinal amines. The polymer can be a homopolymer that includes repeating units of vicinal amines or is a copolymer that includes one or more repeating units of vicinal amines and other monomers, such as, for example, acrylates, methacrylates, acrylamides, methacrylamides, vinyl esters, vinylamides, olecin, styrenic, etc. The size of the polymer can range from, for example, about 500 to about 1,000,000 Daltons.

ES 2 330 693 T3

A vicinal amine monomer useful in the polymers of the invention is the monomer shown in the formula

VII:

<img file="ES2330693T3_D0014.tif" />

where n is zero, one, or greater than 1, each R is independently an appropriate chemical group that complements the valence of nitrogen, and each R 'is independently H, alkyl, or amino.

In another embodiment, the polymer is characterized by a repeating unit having the formula

<img file="ES2330693T3_D0015.tif" />

or a copolymer thereof, in which n is zero, one or greater than 1, each R is, independently, an appropriate chemical group that complements the valence of nitrogen, each R 'is, independently, H, alkyl or amino, and X is a negatively charged organic or inorganic counter ion.

ES 2 330 693 T3

<img file="ES2330693T3_D0016.tif" />

The polymers of the present invention also include polymers characterized by a repeating unit having the formula

<img file="ES2330693T3_D0017.tif" />

where n is zero, one, or greater than 1, each R is independently an appropriate chemical group that complements the valence of nitrogen, each R 'is independently H, alkyl, or amino, and X is a negatively charged organic or inorganic counter ion.

In one embodiment, the R groups of nearby nitrogen atoms are linked together to form a structure such as that represented in formula X

<img file="ES2330693T3_D0018.tif" />

where Q is a bond, alkyl, alkylamino, alkylcarbonyl, alkenyl, aryl, or heterocyclyl.

ES 2 330 693 T3

In the polymers described in the present application, n is zero, one or greater than 1. In preferred embodiments n is 0-5, even more preferably n is zero or 1.

The value of n 'depends on the desired properties of the polymer, the potential use of the polymer and the synthesis techniques used.

The pendant nitrogen atom of formulas VII, VIII, IX and X can be linked to atoms, such as, for example, C, H, O, S, P and N, so that the pendant groups are a nitroso radical, nitro , nitroxide, nitrone, nitrene, isocyanate, carbazide, hydrazino, diazo, imine, or amidine, guanidine, sulphamate, phosphoramidate and heterocycle groups.

Some examples of appropriate R groups include H, halogen, R ", CO2H, CO2R", COR ", C (= NR") (NR "), CN, CONH2, CONR" 2, OR ", SO3R", Si (R ") 3 and P (O) (OR") 2. Appropriate R "groups include H, or an optionally substituted alkyl, acyl, alkylamino, alkenyl, heterocyclyl, and aryl group. The preferred R 'is H, methyl or amino.

The substituents of the R "groups can be ionic entities with oxygen, nitrogen, phosphorus or sulfur. Some examples of substituents are carboxylate, sulfonate, sulfamate, sulfon group, phosphonate, phosphazene, phosphoramidate group, quaternary ammonium groups or primary and secondary amine groups, eg, alkylamines or arylamines. Some examples of other suitable substituents include hydroxy, alkoxy, carboxamide, sulfonamide, halogen, alkyl, aryl, hydrazine, guanadine, urea, and carboxylic acid esters.

Preferred R groups include H and the following groups:

<img file="ES2330693T3_D0019.tif" />

The negatively charged counter ions, X, can be organic ions, inorganic ions, or combinations thereof. Inorganic ions suitable for use in this invention include halide (especially chloride), carbonate, bicarbonate, sulfate, bisulfate, hydroxide, nitrate, persulfate, and sulfite. Appropriate organic ions include acetate, ascorbate, benzoate, citrate, dihydrogen citrate, hydrogen citrate, oxalate, succinate, tartrate, taurocholate, glycolate, and cholate. The X^- preferred is chloride or carbonate.

ES 2 330 693 T3

In a preferred embodiment, the counterion does not have a detrimental side effect for the patient and is chosen to provide a therapeutic or nutritional benefit for the patient.

Another monomer that can be used in the polymers of the invention has the formula XI shown below,

<img file="ES2330693T3_D0020.tif" />

where R "'is H or CH₃, and R has the same meaning as above. Preferred structures of formula XI are those in which R = H.

In one embodiment, the polymer is a copolymer where one of the repeating units is a monomer such as those described in the present application.

The copolymers of the present invention may be alternating or random copolymers. Generally, the monomers that can be copolymerized with the amine precursors include one or more monomers selected from the group consisting of styrene, substituted styrene, alkyl acrylate, substituted alkyl acrylate, alkyl methacrylate, substituted alkyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N, N-dialkylacrylamide, N, N-dialkylmethacrylamide, isoprene, butadiene, ethylene, vinyl acetate, N-vinyl amide, maleic acid derivatives, vinyl ether, allyl, methallyl monomers, and combinations thereof. Functionalized versions of these monomers can also be used. Specific monomers or comonomers that can be used in this invention include, but are not limited to, methyl methacrylate, ethyl methacrylate, propyl methacrylate (all isomers), butyl methacrylate (all isomers), 2-ethylhexyl methacrylate, isobornyl methacrylate, methacrylic acid, benzyl methacrylate, phenyl methacrylate, methacrylonitrile, α-methylstyrene, methyl acrylate, ethyl acrylate, propyl acrylate (all isomers), butyl acrylate (all isomers), 2-ethylhexyl acrylate, isobornyl acrylate, acrylic acid, benzyl acrylate, phenyl acrylate, acrylonitrile, styrene, glycidyl methacrylate, 2-hydroxyethyl methacrylate (all hydroxypropyl methacrylate (all hydroxypropyl methacrylate) isomers), hydroxybutyl methacrylate (all isomers), N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, triethylene glycol methacrylate, itaconic anhydride, itaconic acid, glycidyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate (all isomers), hydroxybutyl acrylate (all isomers), N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl acrylate, triethylene glycol acrylate, methacrylamide, N-methyl acrylamide N, N-dimethylacrylamide, N-tert-butylmethacrylamide, Nn-butylmethacrylamide, N-methylolmethacrylamide, N-ethylolmethacrylamide, N-tert-butylacrylamide, Nn-butylacrylamide, N-methylolacrylamide, 4-acryl acrylamide, N-methylolacrylamide, 4-acrylamide vinylbenzoic acid (all isomers), diethylaminostyrene (all isomers), α-methylvinylbenzoic acid (all isomers), diethylamino α-methylstyrene (all isomers), p-vinylbenzenesulfonic acid, sodium salts of p-vinylbenzenesulfonic acid, methacrylate trimethoxysilylpropyl, triethoxysilylpropyl methacrylate, tributoxysilylpropyl methacrylate, dimethoxymethylsilylpropyl methacrylate, diethoxymethylsilylpropyl methacrylate, dibutoxymethylsilylpropyl methacrylate, diisopropoximetilsililpropilo methacrylate, dimethoxysilylpropyl methacrylate, diethoxysilylpropyl methacrylate, dibutoxysilylpropyl methacrylate, diisopropoxysilylpropyl methacrylate methacrylate acrylate, trimethoxysilylpropyl acrylate, triethoxysilylpropyl acrylate, tributoxisililpropilo acrylate dimetoximetilsililpropilo acrylate, diethoxymethylsilylpropyl acrylate, dibutoximetilsililpropilo acrylate diisopropoximetilsililpropilo, Dimethoxysilylpropyl acrylate, diethoxysilylpropyl acrylate, dibutoxysilylpropyl acrylate, diisopropoxysilylpropyl acrylate, maleic anhydride, N-phenylmaleimide, N-butylmaleimide, N-vinylformamide, N-vinyl acetaminophen, allyl alcohol, allylamide ethyl vinyl, butyl vinyl ether, butadiene, isoprene, chloroprene, ethylene, vinyl acetate, and combinations thereof. Preferred monomers or comonomers are acrylamide, dimethylacrylamide, N-vinyl formamide, N-vinylacetamide, vinyl acetate, methyl acrylate, and butyl acrylate.

ES 2 330 693 T3

Other monomers that can be used in the polymer of the invention include:

<img file="ES2330693T3_D0021.tif" />

where each R, independently, is H or a substituted or unsubstituted alkyl group, such as, for example, a lower alkyl (eg, having between 1 and 5 carbon atoms, inclusive), alkylamino (eg, having between 1 and 5 carbon atoms, inclusive, such as ethylamino) or aryl (eg, phenyl).

<img file="ES2330693T3_D0022.tif" />

where each R, independently, is H or a substituted or unsubstituted alkyl group (eg, having between 1 and 5 carbon atoms, inclusive), alkylamino (eg, having between 1 and 5 carbon atoms, inclusive, such as ethylamino) or aryl (eg, phenyl), and each X is a negatively charged exchangeable counterion.

Another suitable monomer is a structure of formula

<img file="ES2330693T3_D0023.tif" />

where R is H or a substituted or unsubstituted alkyl group (eg, having between 1 and 5 carbon atoms, inclusive), alkylamino (eg, having between 1 and 5 carbon atoms, inclusive, such as, for example, ethylamino ) or aryl (eg, phenyl).

ES 2 330 693 T3

Another suitable monomer is a structure of formula

<img file="ES2330693T3_D0024.tif" />

where R₁ and R₂, independently, are H or a substituted or unsubstituted alkyl group (eg, having between 1 and 5 carbon atoms, inclusive) and alkylamino (eg, having between 1 and 5 carbon atoms, inclusive, as, for eg, ethylamino) or aryl (eg, phenyl), and each X is an exchangeable negatively charged counterion. In one embodiment, at least one of the R groups is a hydrogen atom.

Another suitable monomer is a structure of formula

<img file="ES2330693T3_D0025.tif" />

where R1 and R2, independently, are H or a substituted or unsubstituted alkyl group containing 1 to 20 carbon atoms, an alkylamino group (eg, having 1 to 5 carbon atoms, inclusive, as, for example, ethylamino) or an aryl group containing 6 to 12 carbon atoms (eg, phenyl).

Another suitable monomer is a structure of formula

<img file="ES2330693T3_D0026.tif" />

<img file="ES2330693T3_D0027.tif" />

where R₁ and R₂ and R₃independently are H or a substituted or unsubstituted alkyl group containing 1 to 20 carbon atoms, an alkylamino group (eg, having 1 to 5 carbon atoms inclusive, such as ethylamino) or an aryl group containing 6 to 12 atoms (eg, phenyl), and each X is a negatively charged exchangeable counterion.

In each case, for these monomers, the R groups can carry one or more substituents. Appropriate substituents include therapeutic anionic groups, eg, quaternary ammonium groups, or amine groups, eg, primary and secondary alkylamines or arylamines. Examples of other suitable substituents include hydroxy, alkoxy, carboxamide, sulfonamide, halogen, alkyl, aryl, hydrazine, guanadine, urea, and carboxylic acid esters, for example.

ES 2 330 693 T3

The negatively charged counterions, X^-They can be organic ions, inorganic ions or combinations thereof. Inorganic ions suitable for use in this invention include halide (especially chloride), carbonate, bicarbonate, sulfate, bisulfate, hydroxide, nitrate, persulfate, and sulfite. Appropriate organic ions include acetate, ascorbate, benzoate, citrate, dihydrogen citrate, hydrogen citrate, oxalate, succinate, tartrate, taurocholate, glycolate, and cholate.

Guanidino group-containing polymers are also useful as compositions that can be produced by the processes described in the present application to have the desired properties and that can chelate anions such as, for example, phosphate and oxalate. Such polymers are described in US Patent Nos. 6,132,706 and 5,968,499, which are included in their entirety by reference herein. Briefly, the guanidino groups are attached to the polymer backbone. The nature of the polymer backbone is not of great importance since the chelating effect is due to the guanidino groups. Preferred polymers in which crosslinking and other factors can be controlled include polymers having a polyethylene backbone crosslinked with divinylbenzene. Polymers having an inorganic backbone can also be used, for example polyphosphazene polymers. The polymers can be copolymers derived from two or more different types of monomers. Additional examples of useful polymers are carbohydrate polymers, including cellulose and agarose. Guanidino groups are attached to the polymer backbone by means of a chemical bond through the terminal NH group of the guanidino group (NH2-C (= NH) -NH-). Guanidino groups can be chemically attached to the polymer backbone directly or through some form of grouping that acts as a "spacer" through which it is attached to the polymer backbone. Various forms of attachment can be used, with the preferred forms varying depending on the basic type of polymer. For example, alkylene groups of 1-4 carbon atoms, amide groups, ether groups, or a combination thereof can be used. The preferred mode of attachment of the guanidino groups to the polymer backbone will obviously depend on the nature of the backbone, but, for simplicity, direct bonding between backbone atoms and the NH group of the guanidino group is preferred whenever possible.

Methods of preparing guanidino-containing polymers will be apparent to the person skilled in the art, but, by way of example, can be prepared following the explanations of Schnaar, RL and Lee, YC, 1975, Biochemistry 14, 1535-1541, included herein in their entirety by reference, which describe a method for binding biologically active ligands to a polymer matrix, or the polymers can also be conveniently prepared by reaction with a polymer containing amino groups attached to the polymer backbone of (a) 3,5-dimethylpyrazole-1-carboxamidine nitrate, (b) S-methylthiouronium sulfate, or (c) O-methylpseudourea acid sulfate.

The preferred monomers of the invention are amines. The most preferred monomers for use in the polymers of the invention include allylamine, vinylamine, ethyleneimine, methylene 1,3-diaminopropane and N, N, N ', N'tetrakis (3-aminopropyl) 1,4 diaminobutane, 1,2, 3,4 tetra-aminobutane, formula 1 and formula 2, where formula 1 and formula 2 are the following structures:

<img file="ES2330693T3_D0028.tif" />

In some embodiments, the polymers of the invention are composed of one or more amine monomers and one or more crosslinkers, where the polymer is produced by a process where the amine is present in the solvent prior to crosslinking in an amine: solvent ratio from about 3: 1 to about 1: 3 and the total content of crosslinkers added to the reaction mixture is such that the average number of connections to the amine monomers is between about 2.05 and about 6, or between about 2.2 and about 4.5. In some embodiments, the polymers of the invention are a phosphate chelating polymer composed of one or more amine monomers and one or more crosslinkers, where the polymer is produced by a process where the total content of crosslinkers added to the mixture The reaction rate is such that the average number of connections with the amine monomers is between 2.2 and 4.5. In preferred embodiments, the amine monomer is chosen from the group consisting of 1,3-diaminopropane and N, N, N ', N'-tetrakis (3-aminopropyl) 1,4-diaminobutane, and where the crosslinking agent is chosen from the group consisting of 1,3 dichloropropane and epichlorohydrin. In some embodiments, the polymers of the invention are composed of one or more amine monomers and one or more crosslinkers, where the amine monomers are not polyallylamine monomers and / or the crosslinkers are not epichlorohydrin.

In some embodiments, eg, in phosphate chelating polymers, it is desirable to keep the chloride to amine ratio of the final polymer below certain levels. In some embodiments, this is from about 0 to about 35 mol%, preferably from about 0 to about 15 mol%. The monomers can be chosen according to this criterion.

ES 2 330 693 T3

D. Crosslinking agents

Crosslinkers include those described in U.S. Patent Nos. 5,496,545, 5,667,775,

6,509,013, 6,132,706 and 5,968,499 and in United States Patent Applications 10 / 806,495 and

10/701.385.

Crosslinking agents are typically compounds that have at least two functional groups chosen from a halogen group, a carbonyl group, an epoxy group, an ester group, an acid anhydride group, an acid halide group, an isocyanate group, a vinyl group and a chloroformate group. The crosslinking agent can be attached to the carbon skeleton or pendant nitrogen of the amine polymer. Examples of cross-linkers that are suitable for the synthesis of the polymers of the present invention include, but are not limited to, the cross-linkers shown in Table 2.

TABLE 2

<td>Label</td><td>Structure</td><td>P.m</td>

<td>X-EP-1</td><td>° L&gt; ^</td><td> 92,52</td>

<td>X-EP-2</td><td></td><td> 174,19</td>

<td>X-EP-3</td><td>_&lt;p&gt; ^ cAo</td><td></td>

<td>X-EP-4</td><td></td><td> 302,37</td>

<td>X-EP-5</td><td>° ν η or</td><td> 297,27</td>

<td>X-EP-6</td><td></td><td> 277,32</td>

<td>X-EP-7</td><td>r ^ í</td><td> 86,09</td>

ES 2 330 693 T3

<img file="ES2330693T3_D0029.tif" />

ES 2 330 693 T3

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ES 2 330 693 T3

<td>Label</td><td>Structure</td><td>P.m</td>

<td>X-Mc-1</td><td>or</td><td> 168,2</td>

<td>X-Mc-2</td><td>or</td><td> 118,16</td>

<td>X-Mc-3</td><td></td><td> 249,27</td>

<td>X-IC-1</td><td>OCN'x / X / X / x nco</td><td> 168,19</td>

<td>X-lC-2</td><td>NCO</td><td> 174,16</td>

<td>X-IC-3</td><td>cf '—NCO</td><td> 188,18</td>

<td>X-íC-4</td><td>ocnOQ '³⁰</td><td> 222,28</td>

ES 2 330 693 T3

<td>Label</td><td>Structure</td><td>P.m</td>

<td>X-ME-1</td><td> 0</td><td> 86,09</td>

<td>X-ME-2</td><td> 0</td><td> 158,16</td>

<td>X-ME-3</td><td> 0</td><td> 146,14</td>

<td>X-ME-4</td><td>F 0</td><td> 194,19</td>

<td>X-ME-5</td><td>^{/ j}yTt⁰'' or 0. or O'Xj)</td><td> 234,2</td>

<td>X-ME-6</td><td>I ° x ° ^ΟγΥγ / ° Χ _xor 0</td><td> 252,22</td>

<td>X-ME-7</td><td></td><td> 194,19</td>

ES 2 330 693 T3

<td>Label</td><td>Structure</td><td>P.m</td>

<td>X-ME-6</td><td>oh o 0 OH</td><td> 178,14</td>

<td>X-ME-9</td><td> 0</td><td> 108,53</td>

Examples of suitable crosslinking agents are diacrylates and dimethacrylates (eg, ethylene glycol diacrylate, propylene glycol diacrylate, butylene glycol diacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, butylene glycol dimethacrylate, polyethylene glycol dimethacrylate, methyl ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate). methylene-bismethacrylamide, ethylene-bisacrylamide, ethylene-bismethacrylamide, ethylidene-bisacrylamide, divinylbenzene, bisphenol A dimethacrylate, bisphenol A diacrylate, diepoxides, dihalides, diisocyanates, diacyl chlorides, dianhydrides, and dimethyl esters.

Examples of preferred crosslinking agents include epichlorohydrin, 1,4-butanediol diglycidyl ether, 1,2-ethanediol diglycidyl ether, 1,3-dichloropropane, 1,2-dichloroethane, 1,3-dibromopropane, 1,2-dibromoethane, succinyl dichloride, dimethyl succinate, toluene diisocyanate, acryloyl chloride, methyl acrylate, ethylene bisacrylamide, and pyromellitic dianhydride.

E. Polymerization

Polymerization can be achieved by methods known in the art, examples of which are illustrated in detail in the Examples disclosed in the present application. As described above, the polymerization conditions can be regulated to produce polymers with the desired characteristics.

The crosslinking reaction is carried out either in a block solution (ie, using the pure amine and crosslinking compounds) or in a dispersed medium. The crosslinking reaction that results in gel formation can be carried out using a variety of processes; These processes fall into two categories:

i) homogeneous processes in which the functional precursor of the amine (small molecule amine or high molecular weight polyamine) is soluble in the continuous phase and where the gel, obtained through a crosslinking reaction, is obtained in the form of a block gel or as a gel suspension in said continuous phase. The bulk gel process describes a situation where all of the solvent is trapped in the gel lattice to form a mass that is then fragmented into smaller particles by extrusion, grinding, or related methods. When using a block process the solvents are chosen so that they can dissolve the reactants together and do not interfere with the crosslinking reaction of the amine. Appropriate solvents include water, low boiling point alcohols (methanol, ethanol, butanol), dimethylformamide, dimethyl sulfoxide, acetone, methyl ethyl ketone, etc. A gel suspension is typically obtained where the viscosity of the reaction medium is in the lower range and the shear rate is high, whereby gel fragments are produced which remain in suspension in the form of a light liquid mixture.

ii) Heterogeneous processes in which the functional amine precursor (small molecule amine or high molecular weight polyamine) is made insoluble in the continuous phase so that it forms small dispersed droplets or particles which are then subjected to a crosslinking reaction, forming granules or particles of irregular shape that are kept in suspension in said continuous phase.

Homogeneous processes can be impractical for crosslinked material with limited expansion ratios, as, for example, those considered in this invention: the typical degree of crosslinking for the desired range of expansion ratio and pore size usually causes a time very short gelling and high local viscosity, both being impractical in large-scale manufacturing.

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A preferred mode of synthesis for the present invention is the use of heterogeneous processes. Such processes are also called dispersed medium polymerization and include reverse suspension, direct suspension, precipitation polymerization, emulsion polymerization and microemulsion polymerization, aerosol reaction, etc. The continuous phase can be chosen from nonpolar solvents such as, for example, toluene, benzene, hydrocarbons, halogenated solvents, supercritical carbon dioxide, etc. With a direct suspension or emulsion process, water can be used, although brine is also useful to "salt" the amine and crosslinking reagents in a separate phase of small droplets, as described in US Patent 5,414,068. . The monomer precursors can be dispersed in the continuous phase either in the pure state or in the form of a solution. The amine and the crosslinker are preferably incorporated in two different stages, in which the amine is dispersed first in the form of small droplets and subsequently the crosslinker is added to the reaction medium and migrates to the dispersed phase. The crosslinking reaction takes place in the droplet phase without causing any significant increase in viscosity in the dispersion. This has the advantage of dissipating the heat generated by the exothermic reaction, while ensuring good homogeneity of the gel in the granules. A preferred mode of synthesis comprises the following steps:

i) dissolving the amine monomer or amine polymer in water ii) neutralizing a fraction of the amine with an acid, such as, for example, HCl, iii) dispersing said amine solution in a water-immiscible solvent to form an emulsion iv) add the crosslinking agent to the emulsion in a stepwise manner

v) allow the crosslinking reaction to proceed to completion vi) remove water by distillation vii) isolate the granules by filtration viii) wash and dry

In this process the polymer particles are obtained in the form of spherical granules, the diameter of which is preferably kept in the range of 5 to 500 microns, preferably 25 to 250 microns. In some of these embodiments, the granules have an average diameter of less than 40 microns.

Thus, in one aspect, the invention provides a method for preparing an anion-chelating polymer that chelates a target anion, comprising combining an amine monomer with a cross-linker through a heterogeneous process, wherein the phosphate-chelating polymer is characterized by al Minus two of the following attributes: a) an expansion ratio of less than about 5, or less than about 4.5, or less than about 4, or less than about 3; b) be less than approximately 20% of the weight of the polymer accessible to non-interacting solutes of molecular weight greater than approximately twice the MW of the target anion, where said percentage is measured in a physiological medium; and c) an ion chelation interference relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer. In some embodiments, the amine monomer is a polyallylamine. In some embodiments, the crosslinker is epichlorohydrin.

In another aspect, the invention provides an anion chelating polymer that chelates a target ion, where the polymer is produced by a process that comprises crosslinking a polyallylamine by a heterogeneous process, and where said polymer is characterized by at least two of the following attributes : a) an expansion ratio of less than about 5, or less than about 4.5, or less than about 4, or less than about 3; b) be less than approximately 20% of the weight of the polymer accessible to non-interacting solutes of molecular weight greater than approximately twice the MW of the target anion, where said percentage is measured in a physiological medium; and c) an ion chelation interference relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer. In one embodiment, the polyallylamine is cross-linked by epichlorohydrin.

As discussed above, the molar ratios of crosslinker to amine determine the amount of gel material formed, as well as the density of its crosslinking. Too small a ratio can lead to incomplete crosslinking and the formation of soluble oligomers, while too high a ratio can produce an extremely compact network with poor chelating properties. The amine component can be a single or a combination of various amines, and the same applies to the crosslinking component. For any new combination of amines and crosslinkers, optimization may be necessary, as the functionality of either one can influence the extent of gel formation and swelling characteristics. In some embodiments, eg, embodiments of low molecular weight monomers crosslinked by crosslinking agents with an Fb of 2, molar ratios between crosslinking agent and amine (B / A) ranging from about 0.2 to about 10, preferably about 0.5 to about 5, and most preferably

ES 2 330 693 T3 about 0.5 to about 2. These ratios can be modified depending on whether the amine monomer is a high molecular weight or a low molecular weight monomer, and / or the Fb value of the crosslinker (see exhibit and table above).

In some cases, the polymers crosslink after polymerization. One method of achieving such cross-linking involves reacting the polymer with dysfunctional cross-linkers, such as, for example, epichlorohydrin, succinyl dichloride, the diglycidyl ether of bisphenol A, pyromellitic dianhydride, toluene diisocyanate, and ethylenediamine. A typical example is the reaction of poly (ethyleneimine) with epichlorohydrin. In this example, epichlorohydrin (1 to 100 parts) is added to a solution containing polyethyleneimine (100 parts) and heated to promote the reaction. A typical example is the reaction of polyvecinalamine with epichlorohydrin. In this example, epichlorohydrin (1 to 200 parts) is added to a solution containing polyvecinalamine (100 parts) and heated to promote the reaction. Other methods of inducing crosslinking in already polymerized materials include, but are not limited to, exposure to ionizing radiation, ultraviolet radiation, radical electron beams, and pyrolysis.

The crosslinking reaction is carried out in batch or semi-continuous mode. In the latter mode, the amine or crosslinker is incorporated as an initial charge and the co-reactant is measured over a given period of time. In one embodiment, a prepolymer is first prepared by incorporating all of the amine component and then continuously adding a portion of the crosslinker, forming a syrup. The syrup is then emulsified in the form of small drops in a continuous oil phase, the remainder of the crosslinking agent being added to form crosslinked granules. When the crosslinker is an alkyl halide compound, a base can be used to recover the acid formed during the reaction. Inorganic or organic bases are suitable. NaOH is preferred. The ratio of base to crosslinker is preferably between about 0.5 and about 2.

In some embodiments, the polymers are subsequently subjected to amination (subsequent reaction with 3-chloropropylamine). In this embodiment, a preliminary reaction is carried out between an amine monomer and a crosslinker to form a gel, and subsequently the gel is reacted with an aminoalkyl halide where the aminoalkyl groups are chemically attached to the gel by means of replacement of the halide by amine functional gels.

All polymers described in the present application can be further cross-linked and labeled with an anion, eg, phosphate. In one embodiment, the target anion (eg, phosphate or oxalate) is present during polymerization and is then removed by washing when the polymerization reaction is complete. The method is called "imprinting" and it tends to increase the chemical affinity of the gel for the solute containing the anion by creating small "molded" pockets in the gel that have a high capacity to recognize and chelate a given anion. Examples of phosphate imprinted gels are described in, eg, Fujiwara et al., Analytical Sciences, April 2000, vol. 16, 407, and No. 703 of the monographic collection of the ACS symposium, “Molecular and Ionic Recognition with Imprinted Polymers”, Bartsch, RA and Maeda, M. editores, 1998, Cap. 22, 315. Typically, the anion is present in a molar ratio to amine (expressed as nitrogen atoms) from about 10% to about 100%, more preferably from about 10% to about 60%, most preferably from about 30% to about 50%. Most preferably, the anion is incorporated as the acid (eg, phosphoric acid, oxalic acid) and the amine as the free base, so that the ammonium / anion salt is formed in situ. The crosslinking is then performed as described above, using the appropriate ratio of crosslinking agent to amine to obtain the desired gel characteristics in terms of swelling ratio, critical permeation volume, and interference in chelation. The gel formed immediately after crosslinking is then thoroughly washed in a very acidic (eg, pH &lt;2) or very basic (eg, pH&gt; 12) medium to remove the imprinted anion and then washed again with a neutral medium. If all the parameters are kept the same (eg, the ratio of the amine to the crosslinker, the ratio of the monomer to the solvent), the printing method described here usually increases the chelating capacity by a factor of 1.1 , 1.3 or even 1.5.

III. Pharmaceutical Compositions

In one aspect, the invention provides pharmaceutical compositions. In one embodiment, the pharmaceutical compositions are chewable tablets. In another embodiment, the pharmaceutical compositions are liquid formulations.

The pharmaceutical compositions of the present invention include compositions in which the polymers of the invention, eg, cross-linked amine polymers, are present in an effective amount, ie, in an amount effective to achieve a therapeutic and / or prophylactic benefit. The actual effective amount for a particular application will depend on the patient (eg, age, weight), the condition being treated, and the route of administration. Determination of the effective amount is entirely within the knowledge of those skilled in the art, especially in light of what is disclosed in the present application.

The effective amount for use in humans can be determined from animal models. For example, a human dose can be formulated to achieve circulating and / or gastrointestinal concentrations that have been shown to be effective in animals.

ES 2 330 693 T3

The pharmaceutical compositions comprise the polymer, eg, cross-linked amine polymers, one or more pharmaceutically acceptable carriers, diluents or excipients, and optionally additional therapeutic agents.

The pharmaceutical compositions to be used according to the present invention can be formulated in a conventional manner using one or more physiologically acceptable carriers comprising excipients and auxiliaries that facilitate the processing of the active compounds to give preparations that can be used pharmaceutically. The appropriate formulation depends on the chosen route of administration. Some appropriate methods for the preparation of pharmaceutical compositions of the amines are well known in the art, eg, Gennaro, AR (ed), Remington's Pharmaeutical Sciences, 20^to edition, Lippincott, Williams and Wilkins, Baltimore MD (2001), which is included in full for reference in this document.

The present pharmaceutical compositions are generally prepared by known methods using well known and readily available ingredients. In making the compositions of the present invention, the ion chelating polymer, eg, phosphate chelating polymer, may be present alone, may be mixed with a support, diluted in a support, or contained in a support that may be in the form of a capsule, envelope, paper or other container. When the support serves as a diluent, it can be a solid, semi-solid or liquid material that acts as a vehicle, excipient or medium for the polymer. Thus, the compositions can be in the form of tablets, pills, powders, lozenges, sachets, capsules, elixirs, suspensions, syrups, aerosols, (as a solid or in a liquid medium), soft or hard gelatin capsules, sterilized packaged powder. , etc. The preferred formulations are chewable tablets and liquid formulations. Examples of carriers, excipients, and diluents that can be used in these formulations, as well as others, include foods, beverages, lactose, dextrose, sucrose, sorbitol, mannitol, starches, acacia, alginates, tragacanth, gelatin, calcium silicate, cellulose. microcrystalline, polyvinylpyrrolidone, cellulose, methylcellulose, propylhydroxybenzoates and talc.

In another aspect of the invention, the anion (eg, phosphate) chelating polymer is formulated as a free amine, free of counterions. Some short- and medium-term studies have shown that maintenance hemodialysis patients treated with Renagel (polyallylamine hydrochloride) have significantly lower serum bicarbonate levels than patients treated with calcium-containing phosphate binders (that is, they do not contain chlorides). It has been shown (Brezina, B et al., Kidney International, vol.66, suppl.90 (2004), 39-45) that SEVELAMER hydrochloride (trade name of the active pharmaceutical ingredient of Renagel) gives rise to an amount of acid causing acidosis. Acidosis can have serious side effects for this category of patients. In another embodiment, the crosslinked amine polymer is a polyamine polymer wherein the chloride content of the polymer is less than about 40% mole of the content of the amine group, more preferably less than about 20% mole of the content of the amine group, and, even more preferably, less than about 5% of the content of the amine group. More preferably, the polymer is essentially free of chlorine.

A. Chewable tablets

In some embodiments, the polymers of the invention are supplied as pharmaceutical compositions in the form of chewable tablets.

Patient follow-up is recognized today as one of the main limiting factors for patients to adhere to recommendations regarding the treatment of ion imbalance disorders, such as hyperphosphatemia. For example, in treating hyperphosphatemia using current phosphate chelating polymers, such as Renagel, recent studies suggest that patients should take an average of nine to ten 800 mg tablets per day, having to take 25% of the patient population even higher daily doses of twelve to fifteen pills. Renagel is in swallowable tablet form and is administered with the amounts of fluids required to swallow the tablets, increasing discomfort for ESRD patients who are under fluid restriction. The low follow-up of the treatment by the patients due to the large daily doses stands out as a factor that clearly impacts the acceptance of this class of drugs.

An easier to take pharmaceutical formulation would be desirable. Although in many cases administration of the drug by chewable tablets would be very advantageous, its use has been limited because formulators have encountered difficulties in achieving satisfactory sensory characteristics. When chewing a tablet, the following sensory parameters are important: graininess, pastiness, dryness, texture, and overall pleasant taste.

Today's chewable tablets are mostly used in areas where significant amounts of active ingredients need to be administered and include over-the-counter products such as vitamins, antacids, laxatives, and pain relievers. Prescription chews include prenatal vitamins and chewable antibiotics and antivirals that require oral administration of large doses. Although they are often large, their geometry needs to be optimized to allow for easy chewing and appropriate chewing 'hardness'. Rounded beveled shapes with a height / diameter ratio of around 0.3 to 0.4 are common.

ES 2 330 693 T3

In addition to the active ingredient, the following types of excipients are commonly used: a sweetening agent to provide the necessary pleasant taste, plus a binder when the former is inadequate to provide a sufficient consistency to the tablet; a lubricant to minimize friction effects on the die wall and facilitate tablet ejection; and in some formulations a small amount of a disintegrant is added to facilitate chewing. In general, the excipient levels in currently available chewable tablets are on the order of 3-5 times those of the active ingredients, while the sweetening agents make up the bulk of the non-active ingredients.

An important consideration when designing a chewable tablet that contains an ion chelating polymer is the swelling rate of the polymer. Since the invention provides polymers that have low swelling, they can be used in chewable formulations without the unpleasant and sometimes dangerous side effects that accompany chewable tablets of higher swelling polymers. An example of a highly dilated material that causes difficulties during oral administration that can result in obstruction and blockage of the esophagus is Psyllium. Psyllium comes from the crushed seeds of the Plantago ovata plant, an herb native to parts of Asia, the Mediterranean regions of Europe, and North Africa, and is commonly used as a laxative in the United States. Psyllium typically dilates 35-50 times and must be ingested with a large amount of fluids. Insufficient accompaniment of fluids in administration can cause the fiber to dilate and result in obstruction and even rupture of the esophagus. Psyllium is contraindicated in patients with dysphagia and / or a narrow esophagus.

The present invention provides chewable tablets containing a polymer or polymers of the invention and one or more pharmaceutical excipients suitable for the formulation of a chewable tablet. The polymer used in the chewable tablets of the invention preferably has a swelling ratio while transiting the oral cavity and in the esophagus of less than about 5, preferably less than about 4, more preferably less than about 3, more preferably less than 2, 5, and most preferably less than about 2. In some embodiments the polymer is an anion chelating polymer such as a phosphate or oxalate chelating polymer; In a preferred embodiment, the polymer is a phosphate chelating polymer. The tablet comprising the polymer, combined with appropriate excipients, provides acceptable organoleptic properties such as, for example, texture, taste and pastiness, and at the same time does not present a risk of obstruction of the esophagus after chewing and contact with saliva.

In some aspects of the invention, polymers provide mechanical and thermal properties that typically characterize excipients, thus reducing the amount of excipients required by the formulation. In some embodiments, the active ingredient (eg, the polymer, preferably an anion chelating polymer) constitutes above about 30%, more preferably above about 40%, even more preferably above about 50%. %, and most preferably more than about 60% by weight of the chewable tablet, the balance comprising appropriate excipients. In some embodiments the polymer eg, an anion chelating polymer comprises from about 0.6 g to about 2.0 g of the total tablet weight, preferably from about 0.8 g to about 1.6 g. In some embodiments, the polymer eg, an anion chelating polymer, comprises more than about 0.8 g of the tablet, preferably more than about 1.2 g of the tablet, and most preferably more than about 1, 6 g of the tablet. The polymer is prepared to have an appropriate strength / friability ratio and particle size to provide the same qualities for which excipients are often used, eg, adequate hardness, good texture, compressibility, etc. The particle size for the polymers used in the chewable tablets of the invention is less than about 80, 70, 60, 50, 40, 30, or 20 microns in mean diameter. In preferred embodiments the particle size is less than about 80, more preferably less than about 60, and most preferably, less than about 40 microns.

Pharmaceutical excipients useful in the chewable tablets of the invention include a binder, such as, for example, microcrystalline cellulose colloidal silicon dioxide and combinations thereof (Prosolv 90), carbopol, providone, and xanthan gum; a flavoring agent, such as, for example, sucrose, mannitol, xylitol, maltodextrin, fructose, or sorbitol; a lubricant, such as, for example, magnesium stearate, stearic acid, sodium stearylfumurate, and vegetable-derived fatty acids; and optionally, a disintegrant, such as, for example, croscarmellose sodium, gellan gum, low substituted hydroxypropyl cellulose ether, sodium starch glycolate. Other additives can include plasticizers, pigments, talc, etc. Such additives and other suitable ingredients are well known in the art; see, eg, Gennaro, AR (ed) Remington's Pharmaceutical Sciences, 20^to Edition.

In some embodiments the invention provides a pharmaceutical composition formulated as a chewable tablet, comprising a phosphate chelating polymer and an appropriate excipient. In some embodiments the invention provides a pharmaceutical composition formulated as a chewable tablet, comprising a phosphate chelating polymer, a supplement, and a lubricant. In some embodiments the invention provides a pharmaceutical composition formulated as a chewable tablet, comprising a phosphate chelating polymer, a complement, and a lubricant, in which the complement is chosen from the group consisting of sucrose, mannitol, xylitol, maltodextrin, fructose and sorbitol; and wherein the lubricant is a magnesium salt of a fatty acid, such as, for example, magnesium stearate.

ES 2 330 693 T3

The tablet can be of any size and shape compatible with chewability and disintegration in the mouth, preferably cylindrical in shape, with a diameter from about 10mm to about 40mm and a height from about 2mm to about 10mm, more preferably , a diameter of about 22mm and a height of about 6mm.

In one embodiment, the polymer has a transition temperature of greater than about 30 ° C, preferably greater than about 50 ° C.

In another embodiment, the polymer is pre-formulated with a low molecular weight, high Tg / high melting point excipient such as mannitol, sorbose or sucrose, to form a solid solution in which the polymer and the excipient they are intimately mixed. Mixing methods, such as, for example, spray-dried extrusion, freeze-drying, lyophilization, or wet granulation, are useful. The indication of the mixing level is obtained by known physical methods such as, for example, differential scanning calorimetry or dynamic-mechanical analysis.

Methods of preparing chewable tablets containing pharmaceutical ingredients, including polymers, are known in the art. See, eg, European Patent Application No. EP373852A2 and US Patent No. 6,475,510, and Remington's Pharmaceutical Sciences, all of which are included herein by reference in their entirety.

B. Liquid formulations

In some embodiments, the polymers of the invention are supplied as pharmaceutical compositions in the form of liquid formulations. In some embodiments, the pharmaceutical composition contains an ion chelating polymer dispersed in an appropriate liquid carrier. Appropriate liquid excipients are known in the art; see eg, Remington's Pharmaceutical Sciences.

IV. Treatment methods

In another aspect, the invention provides methods of treating ion imbalance disorders. The term "ion imbalance disorders", as used in the present application, refers to conditions in which the level of an ion present in the body is abnormal. In one embodiment, the invention provides methods for treating a phosphate imbalance disorder. The term "phosphate imbalance disorders", as used in the present application, refers to conditions in which the level of phosphorus present in the body is abnormal. An example of a phosphate imbalance disorder includes hyperphosphatemia. The term "hyperphosphatemia", as used in the present application, refers to a condition in which the element phosphorus is present in the body at an elevated level. Typically, a patient is frequently diagnosed with hyperphosphatemia if the blood phosphate level is, for example, above about 4.5 milligrams per deciliter of blood and / or the glomerular filtration rate is reduced to, for example, more of about 20%.

Thus, for example, the invention provides methods of removing an anion in an animal by administering an effective amount of a polymer of the invention to the animal. In some embodiments, the polymer is an anion chelating polymer, where the polymer chelates a target anion (eg, phosphate or oxalate), and where the polymer is characterized by at least two of the following attributes: a) a ratio of dilation less than about 5; b) a gel pore volume distribution measured in a physiological medium characterized by being a fraction of said pore volume accessible to non-interacting solutes, with a molecular weight greater than approximately twice the MW of the target anion, less than approximately 20% of the weight of the gel; and c) an ion chelation interference relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer. In some embodiments, the target anion of the polymer is phosphate; In some embodiments, the phosphate is eliminated from the gastrointestinal tract; In some embodiments, the method of administration is the oral route. In some embodiments, the animal is afflicted by at least one disease from the group consisting of hyperphosphatemia, hypocalcemia, hyperthyroidism, depressed renal synthesis of calcitrol, tetany due to hypocalcemia, renal failure, ectopic calcification of soft tissues, and ESRD. In some embodiments, the animal is a human. It will be appreciated that any polymer described in the present application may be useful for chelating an anion in an animal and / or for the treatment of conditions caused by ion imbalance in an animal. In preferred embodiments, the polymer is a phosphate chelating polymer, where the polymer is characterized by at least one of the following attributes: a) a swelling ratio of less than about 5, preferably less than about 2.5; b) a distribution of the pore volume of the gel measured in a physiological medium characterized by being a fraction of said pore volume accessible to non-interacting solutes, of molecular weight greater than approximately 200, of less than approximately 20% of the weight of the gel ; and c) an ion chelation interference relative to phosphate of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer. In some embodiments, the expansion ratio is less than about 2.8, or less than about 2.7, or less than about 2.6.

ES 2 330 693 T3

Other diseases that can be treated with the methods, compositions and kits of the present invention include hypocalcemia, hyperparathyroidism, hungry bone syndrome, depressed renal synthesis of calcitrol, tetany due to hypocalcemia, renal failure, and ectopic calcification. in soft tissues, including calcifications in the joints and in tissues of the lungs, kidneys, conjunctiva, and myocardium. The present invention can also be used for the treatment of ESRD and dialysis patients, including the prophylactic treatment of any of the foregoing.

Likewise, the polymers described in the present application can be used as a complement to other therapies, eg, those that employ a control of the intake of phosphorus in the diet, inorganic dialysis metal salts and / or other polymer resins.

The compositions of the present invention are also useful for removing chloride, bicarbonate, iron, oxalate, and bile acid ions from the gastrointestinal tract. Polymers that remove oxalate ions find application in the treatment of disorders of oxalate imbalance, such as oxalosis or hyperoxaluria, which increase the risk of kidney stone formation. Polymers that remove chloride ions find application in the treatment of acidosis, heartburn, acid reflux disease, heartburn or gastritis, for example. In some embodiments, the compositions of the present invention are useful for removing fatty acids, bilirubin, and related compounds. Some embodiments can also chelate and remove high molecular weight molecules such as proteins, nucleic acids, vitamins, or cellular debris.

The present invention provides methods, pharmaceutical compositions and kits for the treatment of an animal. The term "animal" or "animal subject", as used in the present application, includes humans as well as other mammals. One embodiment of the invention is a method of removing phosphate from the gastrointestinal tract of an animal by administering an effective amount of at least one of the cross-linked amine polymers described in the present application.

The term "treatment" and its grammatical equivalents, as used in the present application, includes achieving a therapeutic benefit and / or a prophylactic benefit. Therapeutic benefit refers to the eradication, amelioration, or prevention of the underlying disorder being treated. For example, in a hyperphosphatemia patient, the therapeutic benefit includes eradication or amelioration of the underlying hyperphosphatemia. Likewise, a therapeutic benefit is achieved with the eradication, improvement or prevention of one or more of the physiological symptoms associated with the underlying disorder, so that an improvement is observed in the patient, even though the patient may still have the underlying disorder. . For example, the administration of cross-linked amine polymers, described in the present application, to a patient suffering from renal failure and / or hyperphosphatemia provides a therapeutic benefit not only when the patient's serum phosphate level has decreased, but also when the patient's serum phosphate level is decreased. notes an improvement in the patient with respect to other disorders that accompany renal failure and / or hyperphosphatemia, such as ectopic calcification and renal osteodystrophy. For prophylactic benefit, for example, the cross-linked amine polymers may be administered to a patient who is at risk of developing hyperphosphatemia, or to a patient who exhibits one or more of the physiological symptoms of hyperphosphatemia, even though a diagnosis may not have been made. hyperphosphatemia. For example, the polymers of the invention can be administered to a patient with chronic kidney disease who has not been diagnosed with hyperphosphatemia.

Doses of polymer, eg, cross-linked amine polymers, in animals will depend on the disease being treated, the route of administration and the physical characteristics of the animal being treated. In some embodiments using cross-linked amine polymers, the dose levels of the cross-linked amine polymers for therapeutic and / or prophylactic uses can be from about 1 g / day to about 30 g / day. It is preferred that these polymers are administered in conjunction with food. Polymers can be administered once a day, twice a day, or three times a day. The preferred dose range is from about 2 g / day to 20 g / day, and an even more preferred dose range is from about 3 g / day to about 7 g / day. The dosage of the polymers described in the present application may be less than about 50 g / day, preferably less than about 40 g / day, even more preferably less than about 30 g / day, even more preferred less than about 20 g / day. , and, less than about 10 g / day is most preferred.

Preferably, ion chelating polymers, eg, cross-linked amine polymers, used to achieve therapeutic and / or prophylactic benefits can be administered alone or in the form of a pharmaceutical composition as described in the present application. For example, the cross-linked amine polymers of the present invention can be administered in conjunction with other active pharmaceutical agents depending on the condition being treated. Some examples of pharmaceutical agents that can be co-administered include, but are not limited to, proton pump inhibitors, calcimimetics (eg, cinacalcet), vitamin D and analogs thereof, and phosphate binders. Some examples of suitable phosphate chelators include, but are not limited to, aluminum carbonate, calcium carbonate, calcium acetate (PhosLo), lanthanum carbonate (Fosrenol), and Renagel. This co-administration can include simultaneous administration of the two agents in the same dosage form, simultaneous administration in different dosage forms, and administration separately. For example, for the treatment of hyperphosphatemia, cross-linked amine polymers can be co-administered with calcium salts that are used to treat hypocalcemia caused by hyperphosphatemia. The calcium salt and the polymer can be formulated together in the same dosage form and administered simultaneously. Alternatively, the calcium salt and the polymer can be administered simultaneously, when both

ES 2 330 693 T3 agents have independent formulations. In another alternative, the calcium salt can be administered immediately followed by the polymer, or vice versa. In the separate administration protocol, the polymer and calcium salt can be administered within a few minutes, a few hours, or a few days apart.

The polymer can be administered by injection, topically, orally, percutaneously, or rectally. Preferably, the polymer or the pharmaceutical composition comprising the polymer is administered orally. The oral form in which the polymer is administered can comprise a powder, tablet, capsule, solution, or emulsion. The effective amount can be administered in a single dose or in a series of doses separated by appropriate time intervals, such as, for example, hours.

The invention provides methods for the removal of anionic contaminants from wastewater by contacting the wastewater with an anion chelating polymer of the invention, in which the anionic contaminants, eg, phosphate, are absorbed by the polymer.

V. Kits

In still another aspect, the present invention provides kits for the treatment of anion gap disorders, eg, for the treatment of phosphate gap disorders. These kits comprise a polymer or polymers described in the present application and instructions that explain the use of the kit according to the various methods and approaches described in the present application. Such kits may also include information, such as, for example, references to scientific literature, instruction sheets for use, results of clinical trials and / or summaries of these, etc., that indicate or establish the action and / or advantages of the composition. . Such information may be based on the results of various studies, for example, studies using experimental animals incorporating in vivo models, and studies based on human clinical trials. The kits described in this application may have been provided, marketed, and / or promoted to healthcare providers, including physicians, nurses, pharmacists, National Drug Formulary officials, etc. Kits for cosmetic use can be provided, marketed and / or promoted directly to consumers.

All publications and patent applications mentioned in this specification are included in the present application by reference, as if each of the individual publications or patent applications were specifically and individually indicated to be included by reference.

It will be apparent to one of ordinary skill in the art that many changes and modifications can be made to the disclosures offered in the present application without departing from the spirit or scope of the appended claims.

Examples

Example 1

Phosphate chelation measurement protocols

In this Example several protocols are described to measure the ability of a polymer to chelate an anion (in this case phosphate).

Measurements of phosphate chelating capacity in a non-interfering buffer

An aliquot of dry polymer of weight P (g) was mixed with a fixed volume V (l) of the following buffer: 20 mM H₃PO₄, 80 mM NaCl, 100 mM sodium salt of MES (morpholinoethanesulfonic acid) and a pH of 6.5. When a single chelation measurement was made, the last buffer was used. When multiple measurements were made, eg, for the graphical representation of a chelation isotherm, the phosphate concentration of the buffer was varied. The initial concentration of the phosphate ion is designated by P_initial(mM). The solution can be referred to as a non-interfering buffer since it does not contain other alternative solutes that compete with phosphate ions to bind to the polymer resin. After reaching equilibrium, the resin was decanted by centrifugation and the residual phosphate concentration of the supernatant was analyzed by ion chromatography, P_eq(mM). Chelation capacity was calculated as V * (P_initial-P_eq) / P, expressed in mmol / g, as indicated in the tables for the corresponding polymers.

Chelation capacity in a gastrointestinal simulant

This method was designed to reproduce the conditions of use of a phosphate chelating polymer in a GI tract and to measure the chelation characteristics of the polymer in relation to phosphate (target solute) in the presence of other metabolites (competing solutes). A liquid food was artificially digested in the presence of pepsin

ES 2 330 693 T3 and pancreatic juice to produce a gastrointestinal (GI) simulant. The sequence of incorporation of the enzymes and the pH profile were controlled so that the digestion process was simulated down to the level of the jejunum:

The following components were added one by one in the following order: 291 g powdered milk, 72.8 g Beneprotein, 152 g dextrose, 156 g Polycose g and 17.6 g NaCl, to ~ 2.5 l H₂Or double distilled until dissolved (stirred vigorously, but foaming was avoided). When the NaCl had dissolved, 240 g of corn oil was added. The volume was then made up to 4 L with double distilled H2O. The mixture was vigorously stirred for 2 hours. At that time, the pH was ~ 6.4. Then, 153 ml of 3M HCl was added dropwise to a final pH of 2.0 (~ 150 ml). The mixture was stirred for 15 minutes, after which the pH rose to ~ 2.1. Next, 800 ml of pepsin was added to 10 mM HCl to achieve a final concentration of 1 mg / ml. The mixture was stirred at room temperature for 30 minutes, after which the pH was ~ 2.3. Then, 5 μl of a standard solution of pancreatin and bile salts in 100 mM NaHCO were added.₃, pH 8.4, until reaching a final concentration of 0.3 mg / ml of pancreatin and 2 mg / ml of bile salts. The mixture was stirred for 120 minutes at room temperature, after which the pH was ~ 6.5. The mimic food was stored at -80 ° C for one month before being used.

An aliquot of the GI simulant was centrifuged and the supernatant was analyzed for phosphate content. The phosphate chelation assay was as described above with a non-interfering buffer, except that liquid from the GI simulant was used.

Chelation capacity in ex vivo aspirates

Using a tube placed in the lumen of the small intestine, healthy patients were given a food with the same composition as the preparation for the GI simulant described above, and then aliquots of the chyme were sampled.

Subjects were intubated with a double-lumen polyvinyl tube with a mercury-loaded bag at the end of the tube to facilitate movement of the tube in the small intestine. Using fluoroscopy to guide placement, one of the dual lumen tube openings was placed in the stomach and the other was placed in the ligament of Treitz (in the upper jejunum).

After correct placement of the tube, 550 ml of the liquefied test food (supplemented with a marker, polyethylene glycol (PEG) - 2 g / 550 ml) was infused into the stomach through the gastric opening at a rate of 22 ml per minute. . It took approximately 25 minutes for all the food to reach the stomach, simulating the length of time required to eat normal meals.

Chyme was aspirated from the jejunum of the tube whose lumen had been located at the ligament of Treitz. This fluid was collected continuously at 30 minute intervals over a two and a half hour period. This resulted in 5 samples that were mixed, their volume measured, and lyophilized.

A phosphate chelation test was carried out on the ex vivo aspirates. The phosphate chelation method was as described above with a non-interfering buffer, except that the liquid from the aspirate was used ex vivo (after reconstitution of the freeze-dried material in the appropriate amount of deionized water). The phosphate chelating capacity in the ex vivo aspirate was calculated in the same way as in the experiments with GI simulants.

Example 2

Crosslinked Polymer Libraries Formed by Block Solution Process and Measurement of Phosphate Chelating Capability

Creation of Polymer Libraries

Each of the following five examples comprises a library comprised of up to 24 cross-linked polymers. The polymers have been prepared in batch feed reactors placed in a 4x6 matrix arrangement. Each reactor had a volume of 350 microliters or 3 ml, was subjected to magnetic stirring and its temperature was controlled. In a typical method, the amines, cross-linkers, solvents, and optionally bases were dispersed by robot in each reactor, and optionally stirred. The reactors were then sealed and heated to the indicated temperature for 15 hours. The reactor matrix was then disassembled and cross-linked polymer blocks were transferred to glass flasks, ground, repeatedly washed with deionized water, and lyophilized. The five libraries are identified below in Table 3 along with the corresponding reaction conditions used in their creation.

ES 2 330 693 T3

TABLE 3

<td>Example</td><td>Library Identification</td><td>Reaction temperature (° C)</td><td>Reactor volume (microliters)</td>

<td> 1</td><td> 100275</td><td> 85</td><td> 350</td>

<td> 2</td><td> 100277</td><td> 60</td><td> 350</td>

<td> 3</td><td> 100279</td><td> 80</td><td> 350</td>

<td> 4</td><td> 100353</td><td> 80</td><td> 350</td>

<td> 5</td><td> 100384</td><td> 80</td><td> 3000</td>

Measurements of phosphate chelating ability in a non-interfering buffer

The phosphate ion chelation capacities were also determined for each of the polymers in the libraries. For the method, see Example 1.

Results

Tables 4-8 show the materials and amounts used in the formation of the polymers of each of the 5 libraries, as well as the phosphate chelation capabilities measured in a non-interfering buffer for the polymers formed. The items in the tables correspond to the weight in mg of the chemicals used in each reaction well, as well as the phosphate chelating capacity of the polymer gel obtained (a blank item indicates that no cross-linked gel was formed in that particular reaction ).

(Table goes to next page)

ES 2 330 693 T3

TABLE 4

Library: Tray 3 (ID: 100275) Unit: mg

<td>Row</td><td>Cabbage</td><td>Water</td><td>B-SM- 2 2-DA</td><td>X-Cl- 3</td><td>NaOH</td><td>DMSO</td><td>Phosphate chelation</td>

<td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>(mmol / g)</td>

<td> 1</td><td> 1</td><td> 128,51</td><td> 67,74</td><td> 51,63</td><td> 9,14</td><td> 0,00</td><td></td>

<td> 1</td><td> 2</td><td> 130,70</td><td> 57,94</td><td> 61,82</td><td> 10,94</td><td> 0,00</td><td></td>

<td> 1</td><td> 3</td><td> 132,33</td><td> 50,61</td><td> 69,43</td><td> 12,29</td><td> 0,00</td><td></td>

<td> 1</td><td> 4</td><td> 133,59</td><td> 44,93</td><td> 75,33</td><td> 13,33</td><td> 0,00</td><td> 3,042</td>

<td> 1</td><td> 5</td><td> 134,60</td><td> 40,39</td><td> 80,04</td><td> 14,17</td><td> 0,00</td><td> 0</td>

<td> 1</td><td> 6</td><td> 135,43</td><td> 36,69</td><td> 83,89</td><td> 14,85</td><td> 0,00</td><td> 0</td>

<td> 2</td><td> 1</td><td> 136,42</td><td> 32,26</td><td> 88,50</td><td> 15,66</td><td> 0,00</td><td> 3,703</td>

<td> 2</td><td> 2</td><td> 137,05</td><td> 29,41</td><td> 91,45</td><td> 16,19</td><td> 0,00</td><td> 3,624</td>

<td> 2</td><td> 3</td><td> 137,58</td><td> 27,03</td><td> 93,93</td><td> 16,63</td><td> 0,00</td><td> 2,858</td>

<td> 2</td><td> 4</td><td> 138,03</td><td> 25,00</td><td> 96,03</td><td> 17,00</td><td> 0,00</td><td> 2,566</td>

<td> 2</td><td> 5</td><td> 138,42</td><td> 23,26</td><td> 97,84</td><td> 17,32</td><td> 0,00</td><td> 2,761</td>

<td> 2</td><td> 6</td><td> 138,76</td><td> 21,74</td><td> 99,42</td><td> 17,60</td><td> 0,00</td><td> 2,82</td>

<td> 3</td><td> 1</td><td> 132,04</td><td> 64,98</td><td> 49,52</td><td> 17,53</td><td> 34,60</td><td></td>

<td> 3</td><td> 2</td><td> 134,77</td><td> 55,13</td><td> 58,82</td><td> 20,82</td><td> 47,26</td><td></td>

<td> 3</td><td> 3</td><td> 136,79</td><td> 47,87</td><td> 65,67</td><td> 23,25</td><td> 57,22</td><td></td>

<td> 3</td><td> 4</td><td> 138,34</td><td> 42,30</td><td> 70,93</td><td> 25,11</td><td> 65,27</td><td> 3,087</td>

<td> 3</td><td> 5</td><td> 139,57</td><td> 37,90</td><td> 75,09</td><td> 26,58</td><td> 71,91</td><td> 2,946</td>

<td> 3</td><td> 6</td><td> 140,56</td><td> 34,32</td><td> 78,47</td><td> 27,78</td><td> 77,48</td><td> 2,535</td>

<td> 4</td><td> 1</td><td> 141,75</td><td> 30,06</td><td> 82,48</td><td> 29,20</td><td> 79,73</td><td> 2,674</td>

<td> 4</td><td> 2</td><td> 142,50</td><td> 27,35</td><td> 85,04</td><td> 30,11</td><td> 90,45</td><td> 3,038</td>

<td> 4</td><td> 3</td><td> 143,13</td><td> 25,09</td><td> 87,18</td><td> 30,86</td><td> 97,98</td><td> 2,895</td>

<td> 4</td><td> 4</td><td> 143,66</td><td> 23,17</td><td> 88,99</td><td> 31,50</td><td> 103,56</td><td> 2,571</td>

<td> 4</td><td> 5</td><td> 144,12</td><td> 21,52</td><td> 90,54</td><td> 32,05</td><td> 107,86</td><td> 2,636</td>

<td> 4</td><td> 6</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td> 5,374</td>

ES 2 330 693 T3

TABLE 5

<td>Biblic</td><td>&gt; teak</td><td>: Band;</td><td>to 1 (ID</td><td> : 10021</td><td>Π) Unit</td><td>ad: mg</td><td>Chelation</td>

<td>Row</td><td>Cabbage</td><td>Water</td><td>B-SM- 20-TeA</td><td>X-EP- 1</td><td>X-EP-4</td><td></td><td>phosphate (mmol / g)</td>

<td> 1</td><td> 1</td><td> 123,69</td><td> 110,75</td><td> 12,95</td><td> 0,00</td><td>DMF</td><td></td>

<td> 1</td><td> 2</td><td> 124,02</td><td> 107,66</td><td> 16,36</td><td> 0,00</td><td> 0,00</td><td></td>

<td> 1</td><td> 3</td><td> 124,33</td><td> 104,74</td><td> 19,59</td><td> 0,00</td><td> 0,00</td><td></td>

<td> 1</td><td> 4</td><td> 124,63</td><td> 101,98</td><td> 22,65</td><td> 0,00</td><td> 0,00</td><td></td>

<td> 1</td><td> 5</td><td> 124,91</td><td> 99,35</td><td> 25,55</td><td> 0,00</td><td> 0,00</td><td> 4,183</td>

<td> 1</td><td> 6</td><td> 125,17</td><td> 96,86</td><td> 28,31</td><td> 0,00</td><td> 0,00</td><td> 4,237</td>

<td> 2</td><td> 1</td><td> 125,59</td><td> 92,98</td><td> 32,61</td><td> 0,00</td><td> 0,00</td><td> 4,631</td>

<td> 2</td><td> 2</td><td> 125,89</td><td> 90,08</td><td> 35,81</td><td> 0,00</td><td> 0,00</td><td> 4594</td>

<td> 2</td><td> 3</td><td> 126,18</td><td> 87,37</td><td> 38,81</td><td> 0,00</td><td> 0,00</td><td> 4,667</td>

<td> 2</td><td> 4</td><td> 126,45</td><td> 84,81</td><td> 41,64</td><td> 0,00</td><td> 0,00</td><td> 4,586</td>

<td> 2</td><td> 5</td><td> 126,71</td><td> 82,40</td><td> 44,31</td><td> 0,00</td><td> 0,00</td><td> 4,535</td>

<td> 2</td><td> 6</td><td> 126,95</td><td> 80,12</td><td> 46,83</td><td> 0,00</td><td> 0,00</td><td> 4,311</td>

<td> 3</td><td> 1</td><td> 0,00</td><td> 181,12</td><td> 0,00</td><td> 34,60</td><td> 0,00</td><td></td>

<td> 3</td><td> 2</td><td> 0,00</td><td> 159,58</td><td> 0,00</td><td> 47,26</td><td> 104,77</td><td></td>

<td> 3</td><td> 3</td><td> 0,00</td><td> 142,63</td><td> 0,00</td><td> 57,22</td><td> 118,23</td><td> 3,112</td>

<td> 3</td><td> 4</td><td> 0,00</td><td> 128,93</td><td> 0,00</td><td> 65,27</td><td> 128,56</td><td> 2,991</td>

<td> 3</td><td> 5</td><td> 0,00</td><td> 117,63</td><td> 0,00</td><td> 71,91</td><td> 136,73</td><td> 2,798</td>

<td> 3</td><td> 6</td><td> 0,00</td><td> 108,15</td><td> 0,00</td><td> 77,48</td><td> 143,35</td><td> 3,271</td>

<td> 4</td><td> 1</td><td> 0,00</td><td> 104,33</td><td> 0,00</td><td> 79,73</td><td> 148,83</td><td> 3,258</td>

<td> 4</td><td> 2</td><td> 0,00</td><td> 86,08</td><td> 0,00</td><td> 90,45</td><td> 156,12</td><td> 3,062</td>

<td> 4</td><td> 3</td><td> 0,00</td><td> 73,27</td><td> 0,00</td><td> 97,98</td><td> 160,76</td><td> 2,176</td>

<td> 4</td><td> 4</td><td> 0,00</td><td> 63,77</td><td> 0,00</td><td> 103,56</td><td> 164,62</td><td> 2,228</td>

<td> 4</td><td> 5</td><td> 0,00</td><td> 56,46</td><td> 0,00</td><td> 107,86</td><td> 167,88</td><td> 2,407</td>

<td> 4</td><td> 6</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td> 170,67</td><td> 5,224</td>

<td> 4</td><td> 6</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td></td>

ES 2 330 693 T3

TABLE 6

<td colspan="2">library</td><td colspan="3">Tray 3 (ID: 100279</td><td colspan="3">Unit: mg</td>

<td>Row</td><td>Cabbage</td><td>Water</td><td>B-SM- 20-TeA</td><td>X-Cl- 3</td><td>X-Cl- 2</td><td></td><td>Phosphate chelation (mmol / g)</td>

<td> 1</td><td> 1</td><td> 123,95</td><td> 108,47</td><td> 15,49</td><td> 0,00</td><td></td><td></td>

<td> 1</td><td> 2</td><td> 124,34</td><td> 104,88</td><td> 19,47</td><td> 0,00</td><td></td><td></td>

<td> 1</td><td> 3</td><td> 124,70</td><td> 101,51</td><td> 23,19</td><td> 0,00</td><td></td><td></td>

<td> 1</td><td> 4</td><td> 125,04</td><td> 98,36</td><td> 26,68</td><td> 0,00</td><td></td><td></td>

<td> 1</td><td> 5</td><td> 125,36</td><td> 95,40</td><td> 29,97</td><td> 0,00</td><td></td><td> 3,958</td>

<td> 1</td><td> 6</td><td> 125,66</td><td> 92,61</td><td> 33,06</td><td> 0,00</td><td></td><td> 4,309</td>

<td> 2</td><td> 1</td><td> 126,13</td><td> 88,30</td><td> 37,82</td><td> 0,00</td><td></td><td> 4,417</td>

<td> 2</td><td> 2</td><td> 126,47</td><td> 85,14</td><td> 41,33</td><td> 0,00</td><td></td><td> 4,424</td>

<td> 2</td><td> 3</td><td> 126,78</td><td> 82,19</td><td> 44,59</td><td> 0,00</td><td></td><td> 4,392</td>

<td> 2</td><td> 4</td><td> 127,08</td><td> 79,44</td><td> 47,64</td><td> 0,00</td><td></td><td> 4,407</td>

<td> 2</td><td> 5</td><td> 127,36</td><td> 76,87</td><td> 50,49</td><td> 0,00</td><td></td><td> 4,14</td>

<td> 2</td><td> 6</td><td> 127,62</td><td> 74,46</td><td> 53,16</td><td> 0,00</td><td></td><td> 4,314</td>

<td> 3</td><td> 1</td><td> 0,00</td><td> 118,41</td><td> 0,00</td><td> 26,19</td><td></td><td></td>

<td> 3</td><td> 2</td><td> 0,00</td><td> 102,78</td><td> 0,00</td><td> 29,56</td><td></td><td></td>

<td> 3</td><td> 3</td><td> 0,00</td><td> 90,80</td><td> 0,00</td><td> 32,14</td><td></td><td></td>

<td> 3</td><td> 4</td><td> 0,00</td><td> 81,32</td><td> 0,00</td><td> 34,18</td><td></td><td></td>

<td> 3</td><td> 5</td><td> 0,00</td><td> 73,64</td><td> 0,00</td><td> 35,84</td><td></td><td></td>

<td> 3</td><td> 6</td><td> 0,00</td><td> 67,28</td><td> 0,00</td><td> 37,21</td><td></td><td> 2,237</td>

<td> 4</td><td> 1</td><td> 0,00</td><td> 58,81</td><td> 0,00</td><td> 39,03</td><td></td><td> 2,403</td>

<td> 4</td><td> 2</td><td> 0,00</td><td> 53,43</td><td> 0,00</td><td> 40,19</td><td></td><td> 2,704</td>

<td> 4</td><td> 3</td><td> 0,00</td><td> 48,96</td><td> 0,00</td><td> 41,15</td><td></td><td> 2,614</td>

<td> 4</td><td> 4</td><td> 0,00</td><td> 45,17</td><td> 0,00</td><td> 41,97</td><td></td><td> 1,714</td>

<td> 4</td><td> 5</td><td> 0,00</td><td> 41,93</td><td> 0,00</td><td> 42,67</td><td></td><td> 2,294</td>

<td> 4</td><td> 6</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td></td><td> 5,295</td>

ES 2 330 693 T3

TABLE 7

<td colspan="4">Library: Tray 1 (ID:</td><td> 100353:</td><td colspan="3">Unit: mg</td>

<td>Row</td><td>Cabbage</td><td>B-SM- 20-TeA</td><td>B-SM- 2 2-DA</td><td>X-CI- 3</td><td>NaOH</td><td></td><td>Phosphate chelation (mmol / g)</td>

<td> 1</td><td> 1</td><td> 142,77</td><td> 11,14</td><td> 33,97</td><td> 24,05</td><td></td><td></td>

<td> 1</td><td> 2</td><td> 117,71</td><td> 9,19</td><td> 44,82</td><td> 31,73</td><td></td><td></td>

<td> 1</td><td> 3</td><td> 100,13</td><td> 7,82</td><td> 52,42</td><td> 37,12</td><td></td><td> 5,838</td>

<td> 1</td><td> 4</td><td> 87,12</td><td> 6,80</td><td> 58,05</td><td> 41,10</td><td></td><td> 5,38</td>

<td> 1</td><td> 5</td><td> 77,10</td><td> 6,02</td><td> 62,39</td><td> 44,17</td><td></td><td> 5,549</td>

<td> 1</td><td> 6</td><td> 69,15</td><td> 5,40</td><td> 65,83</td><td> 46,61</td><td></td><td> 5,826</td>

<td> 2</td><td> 1</td><td> 64,71</td><td> 5,05</td><td> 67,75</td><td> 47,97</td><td></td><td> 5,452</td>

<td> 2</td><td> 2</td><td> 57,99</td><td> 4,53</td><td> 70,66</td><td> 50,03</td><td></td><td> 3,358</td>

<td> 2</td><td> 3</td><td> 52,54</td><td> 4,10</td><td> 73,01</td><td> 51,70</td><td></td><td> 3,45</td>

<td> 2</td><td> 4</td><td> 48,02</td><td> 3,75</td><td> 74,97</td><td> 53,08</td><td></td><td> 4,27</td>

<td> 2</td><td> 5</td><td> 44,22</td><td> 3,45</td><td> 76,61</td><td> 54,42</td><td></td><td> 3,469</td>

<td> 2</td><td> 6</td><td> 40,98</td><td> 3,20</td><td> 78,02</td><td> 55,24</td><td></td><td> 4,058</td>

<td> 3</td><td> 1</td><td> 111,71</td><td> 26,16</td><td> 39,87</td><td> 28,23</td><td></td><td></td>

<td> 3</td><td> 2</td><td> 89,37</td><td> 20,93</td><td> 51,04</td><td> 36,14</td><td></td><td></td>

<td> 3</td><td> 3</td><td> 74,48</td><td> 17,44</td><td> 58,49</td><td> 41,41</td><td></td><td> 5,154</td>

<td> 3</td><td> 4</td><td> 63,85</td><td> 14,95</td><td> 63,81</td><td> 45,18</td><td></td><td> 5,784</td>

<td> 3</td><td> 5</td><td> 55,87</td><td> 13,08</td><td> 67,80</td><td> 48,01</td><td></td><td> 5,596</td>

<td> 3</td><td> 6</td><td> 49,66</td><td> 11,63</td><td> 70,91</td><td> 50,20</td><td></td><td> 5,287</td>

<td> 4</td><td> 1</td><td> 46,24</td><td> 10,83</td><td> 72,62</td><td> 51,42</td><td></td><td> 5,261</td>

<td> 4</td><td> 2</td><td> 41,13</td><td> 9,63</td><td> 75,17</td><td> 53,23</td><td></td><td> 4,743</td>

<td> 4</td><td> 3</td><td> 37,04</td><td> 8,67</td><td> 77,22</td><td> 54,67</td><td></td><td> 4,076</td>

<td> 4</td><td> 4</td><td> 33,69</td><td> 7,89</td><td> 78,90</td><td> 55,86</td><td></td><td> 3,924</td>

<td> 4</td><td> 5</td><td> 30,90</td><td> 7,24</td><td> 80,29</td><td> 56,85</td><td></td><td> 2,896</td>

<td> 4</td><td> 6</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td></td><td> 5,287</td>

ES 2 330 693 T3

TABLE 8

<td colspan="3">Library:</td><td colspan="2">Tray 1 (ID:</td><td colspan="2">100384) Unit:</td><td rowspan="2">mg</td><td rowspan="2">Phosphate chelation (mmol / g)</td>

<td></td><td>Row</td><td>Cabbage</td><td>X-CI-3</td><td>B-SM- 2 2-DA</td><td>Water</td><td>NaOH</td>

<td></td><td> 1</td><td> 1</td><td> 643,88</td><td> 422,44</td><td> 1752,36</td><td> 227,94</td><td></td><td></td>

<td></td><td> 1</td><td> 2</td><td> 692,40</td><td> 378,56</td><td> 1743,80</td><td> 245,12</td><td></td><td> 4,362</td>

<td></td><td> 1</td><td> 3</td><td> 731,79</td><td> 342,94</td><td> 1736,85</td><td> 259,06</td><td></td><td> 4,09</td>

<td></td><td> 1</td><td> 4</td><td> 764,40</td><td> 313,44</td><td> 1731,10</td><td> 270,61</td><td></td><td> 3,198</td>

<td></td><td> 1</td><td> 5</td><td> 791,85</td><td> 288,62</td><td> 1726,26</td><td> 280,33</td><td></td><td> 2,951</td>

<td></td><td> 1</td><td> 6</td><td> 815,27</td><td> 267,44</td><td> 1722,12</td><td> 288,62</td><td></td><td> 2,005</td>

<td></td><td> 2</td><td> 1</td><td> 643,86</td><td> 422,44</td><td> 1752,36</td><td> 227,94</td><td></td><td></td>

<td></td><td> 2</td><td> 2</td><td> 692,40</td><td> 378,56</td><td> 1743,80</td><td> 245,12</td><td></td><td></td>

<td></td><td> 2</td><td> 3</td><td> 731,79</td><td> 342,94</td><td> 1736,85</td><td> 259,06</td><td></td><td></td>

<td></td><td> 2</td><td> 4</td><td> 764,40</td><td> 313,44</td><td> 1731,10</td><td> 270,61</td><td></td><td> 4,794</td>

<td></td><td> 2</td><td> 5</td><td> 791,85</td><td> 288,62</td><td> 1726,26</td><td> 280,33</td><td></td><td></td>

<td></td><td> 2</td><td> 6</td><td> 815,27</td><td> 267,44</td><td> 1722,12</td><td> 288,62</td><td></td><td> 4,332</td>

<td></td><td> 3</td><td> 1</td><td> 643,88</td><td> 422,44</td><td> 1752,36</td><td> 227,94</td><td></td><td></td>

<td></td><td> 3</td><td> 2</td><td> 692,40</td><td> 378,56</td><td> 1743,80</td><td> 245,12</td><td></td><td></td>

<td></td><td> 3</td><td> 3</td><td> 731,79</td><td> 342,94</td><td> 1736,85</td><td> 259,06</td><td></td><td></td>

<td></td><td> 3</td><td> 4</td><td> 764,40</td><td> 313,44</td><td> 1731,10</td><td> 270,61</td><td></td><td> 4,511</td>

<td></td><td> 3</td><td> 5</td><td> 791,85</td><td> 288,62</td><td> 1726,26</td><td> 280,33</td><td></td><td> 5,086</td>

<td></td><td> 3</td><td> 6</td><td> 815,27</td><td> 267,44</td><td> 1722,12</td><td> 288,62</td><td></td><td> 4,61</td>

<td></td><td> 4</td><td> 1</td><td> 643,88</td><td> 422,44</td><td> 1752,36</td><td> 227,94</td><td></td><td></td>

<td></td><td> 4</td><td> 2</td><td> 692,40</td><td> 378,56</td><td> 1743,80</td><td> 245,12</td><td></td><td></td>

<td></td><td> 4</td><td> 3</td><td> 731,79</td><td> 342,94</td><td> 1736,85</td><td> 259,06</td><td></td><td></td>

<td></td><td> 4</td><td> 4</td><td> 764,40</td><td> 313,44</td><td> 1731,10</td><td> 270,61</td><td></td><td></td>

<td></td><td> 4</td><td> 5</td><td> 791,85</td><td> 288,62</td><td> 1726,26</td><td> 280,33</td><td></td><td> 4,816</td>

<td></td><td> 4</td><td> 6</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td> 0,00</td><td></td><td> 5,17</td>

Example 3

Synthesis of 1,3-Diaminopropane / Epichlorohydrin Crosslinked Granules Formed in a Suspension Process

A 3 liter reaction vessel was used, comprising a round bottom three neck flask with four side flow regulators. The reaction flask was provided with an oil heating bath, a cold water reflux condenser, and a mechanical stirrer with a 3 inch impeller. In this reaction vessel, a solution of 1,3-diaminiopropane (90.2 g, 1.21 mol) in 90.2 g of water, a surfactant (6.4 g of sodium salt of branched dodecylbenzenesulfonic acid dissolved in 100 g of water) and 1 kg of toluene. This initial charge was stirred at 600 rpm for 2 minutes and continued at 300 rpm for 10 minutes before adding the epichlorohydrin. The 300 rpm speed was maintained throughout the remainder of the experiment. The solution was heated to 80 ° C and was also kept at this temperature throughout the remainder of the experiment.

ES 2 330 693 T3

In another vessel, a 40 mass% solution of epichlorohydrin in toluene was prepared. Using a syringe pump, 1.2 equivalents of epichlorohydrin (134.7 g, (1.45 mol)) were added to the reaction vessel with the initial charge over a period of 3 hours. The reaction was allowed to continue for a further two hours before adding 0.75 equivalents of sodium hydroxide (36.5 g (0.91 mol)) in a 40% by weight solution. The sodium hydroxide solution was added to the reaction via syringe pump over a period of 2.5 hours. The reaction was kept at 80 ° C for another 8 hours.

After this time, the granules that had formed were purified by eliminating toluene, washing them with 1000 ml of acetone, then with methanol, a 20% solution of NaOH (to eliminate the surfactant) and then twice more with deionized water. . The granules were freeze-dried for 3 days to produce a fine white powder weighing 160 g (92% yield) and having a mean diameter of 93 pm.

Example 4

Synthesis of a 1,3-diaminopropane / 1,3-dichloropropane cross-linked polymer

Using water as the solvent, 1000 mg of B-SM-22-DA was mixed with 1524 mg of X-Cl-3 and 2524 mg of water in a 20 ml scintillation vial. The reaction was subjected to magnetic stirring and kept at a temperature of 80 ° C overnight, and then at 90 ° C for a further two hours. 34% by weight of the reaction mixture (1716 mg) was purified by 3 steps of washing in water / centrifugation and 144.7 mg of polymer powder of the present example was obtained.

Example 5

Synthesis of a 1,3-diaminopropane / 1,3-dichloropropane cross-linked polymer

Using water as the solvent, 2000 mg of B-SM-22-DA was mixed with 3048 mg of X-Cl-3 and 5048 mg of water in a 20 ml scintillation vial. The reaction was subjected to magnetic stirring and kept at a temperature of 80 ° C overnight.

After three hours of reaction, 3597 mg of a 30% by weight solution of NaOH in water was added to eliminate the acid formed during the reaction, since the crosslinking agent used was an alkyl halide. 20.3% by weight of the reaction mixture (2773.5 mg) was purified by 3 steps of washing in water / centrifugation and 591.3 mg of polymer powder of the present example was obtained.

Example 6

Synthesis of Crosslinked Granules Prepared with 1,3-Diaminopropane / 1,3-Dichloropropane Using a Prepolymer Approach

Prepolymer preparation

The reaction vessel used was a 250 ml round bottom two necked flask, fitted with a cold water reflux condenser and a magnetic stirrer, operating under an argon atmosphere. A solution of 1,3-diaminopropane (31.15 g, 0.42 mol) dissolved in 30.15 g of water is introduced into this reaction vessel. This initial charge is stirred at 300 rpm. The solution was heated to 80 ° C and was kept at this temperature throughout the entire experiment. Using a syringe pump, 1 equivalent (47.47 g, 40.0 mL, 0.42 mole) of 1,3-dichloropropane (Aldrich 99%) was added over a 2 hour period. The reaction was allowed to continue for another two hours before adding 10 mol% (relative to 1,3-diaminopropane) of sodium hydroxide (1.68 g (0.042 mol) of NaOH, completing the solution to 40% by weight of water). The sodium hydroxide solution was added to the reaction via pipet over a period of 2 minutes. The reaction was kept at 80 ° C for another 4 hours. At 80 ° C the solution is viscous and on cooling to 25 ° C it becomes a solid block that is easily soluble in water.

Purification

Water is added to the solid block, washing it with 200 ml of water and 200 ml of MeOH. It is then added to a 1 liter beaker containing a 50/50 MeOH / isopropyl alcohol solution. The white polymer precipitates. After placing the suspension in a centrifuge, the supernatant liquid is removed. This process is repeated another two times using isopropyl alcohol. The white precipitate is then dried under reduced pressure and at room temperature to remove isopropyl alcohol. Isolated polymer molecular weight: Mn (GPC with respect to polyethyleneimine standard) ~ 600

ES 2 330 693 T3

Synthesis of the cross-linked particles

The white prepolymer (8.7 g) was placed in a flask with 1.3 g of branched dodecylbenzenesulfonic acid sodium salt (a 30% by weight solution in water) and 34.8 g of toluene. This gave a 20% solution by weight of polymer suspended in toluene. The polymer was ground into micrometer particles with a mechanical grinder (Brand: IKA. Model: Ultra-Turax T8). 2.2 g of the resulting suspension were introduced into a 10 ml reaction flask equipped with a heater, a mechanical stirrer and a syringe pump. The reaction flask was charged with another 3779 g of toluene. The flask was heated to 80 ° C and the stirrer was turned on (500 rpm). After 3 hours of stirring at this temperature, 112.2 mg (0.0012 mol) of epichlorohydrin were added over a period of 1.5 hours. The reaction was allowed to continue for another two hours before adding 224.4 mg (0.0056 mol) of sodium hydroxide (in a 40% by weight solution in water), which was incorporated over a period of 2 hours. The reaction was allowed to cool to room temperature and stirring was stopped. The granules were purified by removing toluene, washing with methanol, then with a 20% NaOH solution (to remove surfactant), and two more times with deionized water. The granules were freeze-dried for 3 days to provide a fine white powder. The chelating capacity measured in a non-interfering buffer was 3.85 mmol / g.

Example 7

Synthesis and isolation of a low molecular weight polymer (prepolymer) prepared with 1,3-diaminopropane / 1,3-dichloropropane 1

Abbreviations used in the following examples epichlorohydrin: ECH

N, N, N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane: BTA

Chelation capacity: CQ

In this example, the effect of varying the ratio of monomer (in this case a prepolymer) to solvent in the reaction mixture on chelating capacity and expansion ratio was demonstrated. This Example describes a process consisting of two parts: first, the synthesis of an adduct of a soluble prepolymer from 1,3-diaminopropane and 1,3-dichloropropane, and, second, the preparation of insoluble granules by subsequent crosslinking of the prepolymer with ECH. The second reaction consisted of a reverse suspension process in which the ratio of water to prepolymer was varied. The impact of this variation on chelation performance and dilation was evaluated.

Synthesis of the prepolymer

Step 1 (Prepolymer preparation): The reaction vessel used was a 250 ml round bottom two necked flask fitted with a cold water reflux condenser and a magnetic stirrer, operating under an argon atmosphere. A solution of 1,3-diaminopropane (31.15 g, 0.42 mol) dissolved in 30.15 g of water was introduced into this reaction vessel. This initial charge was stirred at 300 rpm. The solution was heated to 80 ° C and was kept at this temperature throughout the entire experiment. Using a syringe pump, 1 equivalent (47.47 g, 40.0 ml, 0.42 mol) of 1,3 dichloropropane (Aldrich 99%) was added over a 2 hour period. The reaction was allowed to continue for another two hours before adding 10 mol% (relative to 1,3-diaminopropane) of sodium hydroxide (1.68 g (0.042 mol) of NaOH, completing the solution to 40% by weight of water). The sodium hydroxide solution was added to the reaction via pipet over a period of 2 minutes. The reaction was kept at 80 ° C for another 4 hours. At 80 ° C the solution was viscous and on cooling to 25 ° C it transformed into a solid block that was easily soluble in water.

Step 2 (Purification): Water was added to the solid block, washing it with 200 ml of water and 200 ml of MeOH. It was then added to a 1 liter beaker containing a 50/50 MeOH / isopropyl alcohol solution. The white polymer precipitated. After centrifugation, the supernatant liquid was removed. This process was repeated another two times using isopropyl alcohol. The white precipitate was then dried under reduced pressure and at room temperature to remove isopropyl alcohol. Isolated polymer molecular weight: Mn (GPC with respect to polyethyleneimine standard) ~ 600

Synthesis of Crosslinked Micrometer Particles Prepared with a 1,3-Diaminopropane / 1,3 Dichloropropane Prepolymer in a 24-Well Parallel Semi-Continuous Polymerization Reactor

The white prepolymer (8.7 g) was placed in a flask with 1.3 g of branched dodecylbenzenesulfonic acid sodium salt (a 30% by weight solution in water) and 34.8 g of toluene. This gave a 20% solution by weight of polymer suspended in toluene. The emulsion was ground into micrometer particles with a high-pressure homogenizer.

ES 2 330 693 T3 speed (Brand: IKA. Model: Ultra-Turax T8). 2.2 g of the resulting suspension was charged into 24 of the 10 ml flasks of the reactor, which was fitted with a heater, a mechanical stirrer and a syringe pump. Another 3779 g of toluene was charged to each reaction flask. The flasks were heated to 80 ° C and the shaker was turned on (500 rpm). Water was added to the tubes in the amount necessary to obtain various ratios of prepolymer to water. After 3 hours of stirring at this temperature, the desired amount of epichlorohydrin was added (in this Example, epichlorohydrin was added to an amount equal to 20% of the dry weight of the prepolymer) over a period of 1.5 hours. . The reaction was allowed to continue for another two hours before adding 224.4 mg (0.0056 mol) of sodium hydroxide (in a 40% by weight solution in water), which was incorporated over a period of 2 hours. The reaction was allowed to cool to room temperature and stirring was stopped. The granules were purified by removing toluene, washing with methanol, and then with a 20% NaOH solution (to remove the surfactant), and finally with HCl to potentiate the granules. The granules were then washed twice with deionized water to remove excess HCl. The granules were freeze-dried for 3 days to provide a fine white powder.

The chelating capacity (CQ) and the dilatation ratio of the granules synthesized by this method were analyzed in a non-interfering buffer and in a gastrointestinal simulant. The results are summarized in Table 9.

TABLE 9

1,3-dianunopmpane / 1,3-didoropmpane / ECH gel granules. Effect of the ratio of monomer to water on Chelation Capacity and Dilation

<td>Ratio of monomer to water</td><td>CQ (mmol / g) Do not interferent and</td><td>CQ (mmol / g) Simulant GI</td><td>Dilation (g of H₂O / g polymer</td>

<td> 1, 67</td><td> 3,85</td><td> 1, 54</td><td> 2, 92</td>

<td> 1, 42</td><td> 3, 68</td><td> 1,43</td><td> 3,34</td>

<td> 1,25</td><td> 3, 61</td><td> 1,34</td><td> 3,50</td>

<td> 1,11</td><td> 3,55</td><td> 1,34</td><td> 3,70</td>

<td> 0,83</td><td> 3,31</td><td> 1,16</td><td> 5,22</td>

<td> 0,55</td><td> 2,90</td><td> 0,91</td><td> 14,00</td>

These results show that the chelation capacities both in non-interfering buffer and in GI simulant increase as the ratio of monomer to water increases, while the expansion ratio decreases and reaches the desired range.

Example 8

Synthesis of Crosslinked Micrometer Particles from Crushed BTA / ECH Bulk Gel Using a 24-Well Parallel Polymerization Reactor

In this example, the effect of varying the ratio of crosslinking agent to monomer on chelating capacity and expansion ratio was demonstrated.

The following standard solution was prepared: 2 molar equivalents of concentrated HCl were added to 1 molar equivalent of BTA over a period of 2 hours. Water was then added to the solution until the resulting solution reached the following composition in weight percentages: BTA 45% by weight, HCl 10% by weight and water 45% by weight. 0.6 g of the prepared standard solution was introduced into each flask of a 24-well reactor having 5 ml flasks. The desired amount of epichlorohydrin was added to each vial to achieve the monomer: crosslinker ratio tested.

ES 2 330 693 T3

The reactor was heated to 80 ° C for 9 hours. The reactor was allowed to cool. Water was added to each vial to swell the resulting gel. The gel was then ground into micrometer particles with a high speed homogenizer (Brand: IKA. Model: Ultra-Turax T8). The particles were purified by removing water, washing with methanol, then with a 20% NaOH solution, and finally with HCl to protonate the amine functionalized particle. The particles were then washed twice with deionized water to remove excess HCl. The particles were freeze-dried for 3 days to provide a fine white powder.

The results of the studies on chelating and dilation capacity are summarized in Table 10.

TABLE 10

Gel BTA / ECH: Dilation Data and Chelation Capacities versus crosslinker content. Block gels (The ratio of monomer to water is 75% or by weight in Pajarita (2HCl) in water). Monomer to water ratio ranges from 3.5 (ECH: BTA = 0.85) to 4.8 (ECH: BTA = 6.4)

<td>Molar ratio ECH: BTA</td><td>CQ (mmol / g) Not interfering</td><td>CQ (mmol / g) Simulant GI</td><td>Dilation Ratio (g of H₂O / g polymer</td>

<td> 0,70</td><td> 0,00</td><td> 0,00</td><td></td>

<td> 0,85</td><td> 2,23</td><td> 0,35</td><td></td>

<td> 1,00</td><td> 2,46</td><td> 0,49</td><td> 16, 68</td>

<td> 1,15</td><td> 2,57</td><td> 0,49</td><td> 10, 98</td>

<td> 1,30</td><td> 2,84</td><td> 0,58</td><td> 6,15</td>

<td> 1,45</td><td> 2,91</td><td> 0,65</td><td> 4,69</td>

<td> 1,60</td><td> 2,91</td><td> 0,77</td><td> 3,85</td>

<td> 1,79</td><td> 2,88</td><td> 0,85</td><td> 3, 13</td>

<td> 1,98</td><td> 0,00</td><td> 0, 98</td><td> 2,77</td>

<td> 2,00</td><td> 2,46</td><td> 1,00</td><td> 2,55</td>

<td> 2,00</td><td> 2,46</td><td> 1,00</td><td> 2,55</td>

<td> 2,16</td><td> 2,73</td><td> 0,99</td><td> 2,46</td>

<td> 2,35</td><td> 2,67</td><td> 0, 96</td><td> 2,20</td>

<td> 2,40</td><td> 2,17</td><td> 0,93</td><td> 1,97</td>

<td> 2,40</td><td> 2,17</td><td> 0,93</td><td> 1,97</td>

<td> 2,80</td><td> 1,86</td><td> 0, 82</td><td> 1,81</td>

<td> 2,80</td><td> 1,86</td><td> 0,82</td><td> 1,81</td>

<td> 3,20</td><td> 1,63</td><td> 0,73</td><td> 1,84</td>

<td> 3,20</td><td> 1, 63</td><td> 0,73</td><td> 1,84</td>

<td> 3,60</td><td> 1,28</td><td> 0,64</td><td> 1,57</td>

<td> 3,60</td><td> 1,28</td><td> 0, 64</td><td> 1,57</td>

<td> 4,00</td><td> 1,09</td><td> 0,58</td><td> 1,57</td>

ES 2 330 693 T3

<td> 4,00</td><td> 1,09</td><td> 0,58</td><td> 1,57</td>

<td> 4,40</td><td> 0.88</td><td> 0,45</td><td> 2, 03</td>

<td> 4,40</td><td> 0,88</td><td> 0,45</td><td> 2,03</td>

<td> 4,90</td><td> 0,42</td><td> 0,35</td><td> 1,47</td>

<td> 4,90</td><td> 0,42</td><td> 0,35</td><td> 1,47</td>

<td> 5,40</td><td> 0,42</td><td> 0,28</td><td> 1,50</td>

<td> 5,40</td><td> 0,42</td><td> 0,28</td><td> 1,50</td>

<td> 5, 90</td><td> 0,07</td><td> 0,27</td><td> 1,55</td>

<td> 5, 90</td><td> 0, 07</td><td> 0,27</td><td> 1,55</td>

<td> 6,40</td><td> 0,06</td><td> 0,22</td><td> 1,55</td>

<td> 6,40</td><td> 0,06</td><td> 0,22</td><td> 1,55</td>

These data show that the chelating capacity in the GI simulant goes through a maximum as the ratio of the crosslinker to the amine varies. In this particular system, the optimal chelation capacity in the GI simulant is observed at a ratio of the crosslinking agent of 1.8 to 2.8, which corresponds to a NC value of 3.6 to 5.6 respectively. In this crosslinking range, the dilation ratio is minimal. Similar tests can be performed routinely for other monomers and crosslinkers using this polymerization protocol to determine what is the ratio that provides the desired results for the particular use that will be given to the polymer.

Example 9

Synthesis of Crosslinked Micrometric BTA / ECH Granules by Reverse Suspension

The following standard solution was prepared: 2 molar equivalents of concentrated HCl were added to 1 molar equivalent of BTA over a period of 2 hours. Then water and a surfactant (sodium salt of branched dodecylbenzenesulfonic acid, 30% by weight, in water) were added to the solution until the resulting solution reached the following composition in weight percentages: BTA 41.8% by weight , HCl 9.4% by weight, water 41.1% by weight and surfactant (30% by weight in water) 7.7% by weight.

The reaction vessel used was a 0.25 liter three necked round bottom flask with four lateral flow regulators equipped with an oil heating bath, a cold water reflux condenser and a mechanical stirrer with a propellant. 1 inch. 25 g of the prepared standard solution and 75 g of toluene were introduced into this reaction vessel.

In another vessel, a 40 mass% solution of epichlorohydrin in toluene was prepared. Using a syringe pump, the desired amount of ECH was added over a 90 minute period. The reaction was allowed to continue for a further two hours before starting a dehydration using a Dean Stark apparatus. The reaction reached its end point when all the water had been removed from the system. The granules were purified by removing the toluene, washing them with methanol, then with a 20% NaOH solution (to remove the surfactant) and finally with HCl to protonate the granules. They were then washed twice with deionized water to remove excess HCl. The granules were freeze-dried for 3 days to provide a fine white powder.

The results of the studies on chelating and dilation capacity are summarized in Table 11.

ES 2 330 693 T3

TABLE 11

BTA / ECH Gel Granules: Dilation and Chelation Capabilities vs. Crosslinker Content

<td>Molar ratio ECH: BTA</td><td>CQ (mmol / g) Not interfering</td><td>CQ (mmol / g) Digested feed</td><td>Expansion ratio (g of H₂O / g polymer</td>

<td> 1,00</td><td> 2,50</td><td> 0, 58</td><td> 25,29</td>

<td> 1,00</td><td> 2,77</td><td> 0,55</td><td> 13,01</td>

<td> 1,25</td><td> 2,97</td><td> 0,65</td><td> 7,69</td>

<td> 1,25</td><td> 3,03</td><td> 0, 61</td><td> 7,07</td>

<td> 1,50</td><td> 3, 13</td><td> 0,71</td><td> 4,41</td>

<td> 1,50</td><td> 3,14</td><td> 0, 69</td><td> 3,99</td>

<td> 1,75</td><td> 3, 13</td><td> 0,78</td><td> 3,06</td>

<td> 1,75</td><td> 3, 10</td><td> 0, 87</td><td> 3,41</td>

<td> 2,00</td><td> 3, 07</td><td> 0, 99</td><td> 3,13</td>

<td> 2,00</td><td> 2,80</td><td> 1,00</td><td> 2,82</td>

<td> 2,00</td><td> 2,82</td><td> 0,73</td><td> 3, 17</td>

<td> 2,50</td><td> 2,76</td><td> 1,03</td><td> 2,48</td>

<td> 3,00</td><td> 2,56</td><td> 0, 82</td><td> 2,40</td>

<td> 3,50</td><td> 0,00</td><td> 0,71</td><td> 2,28</td>

<td> 3,00</td><td> 2,32</td><td> 0,70</td><td> 2,25</td>

<td> 3,00</td><td> 2, 61</td><td> 0,80</td><td> 2.03</td>

<td> 3,50</td><td> 2,81</td><td> 0,59</td><td> 1,85</td>

<td> 4,00</td><td> 0, 00</td><td> 0, 58</td><td> 1, 99</td>

<td> 4,00</td><td> 2,19</td><td> 0,77</td><td> 1, 93</td>

<td> 4,50</td><td> 2,11</td><td> 0,30</td><td> 1,99</td>

<td> 5,00</td><td> 1,96</td><td> 0, 55</td><td> 1,72</td>

These results show that the chelating capacity in the GI simulant goes through a maximum when varying the ratio of the crosslinker to the amine. In this particular system the optimal chelating capacity in the GI simulant is observed at a crosslinker ratio of 1.75 to 3, which corresponds to a NC value of 3.5 to 6 respectively. In this crosslinking range, the dilation ratio is minimal. Similar tests can be performed routinely for other monomers and crosslinkers using this polymerization protocol to determine what is the ratio that provides the desired results for the particular use that will be given to the polymer.

ES 2 330 693 T3

Example 10

Synthesis of Crosslinked Micrometer Particles from a Crushed Polyallylamine / ECH Gel Block Using a 24-Well Parallel Polymerization Reactor

This Example illustrates the synthesis of a polymer using a high molecular weight monomer and varying the ratios of the monomer to water in the reaction mixture. The conditions employed were identical to those described in Example 8, except that polyallylamine (Mw = 60,000 g / mol) was used instead of BTA. The ratio of ECH to allylamine repeat unit was 1: 0.106 (corresponding to NC of 2.2). The initial ratio of polyallylamine to water was varied from 1: 1 to 1.4. Cross-linked polyallylamine, isolated from Renagel tablets, was used as a comparative example.

<td>Molar ratio of amine to water</td><td>CQ (mmol / g) Not interfering</td><td>CQ (mmol / g) Digested food</td><td>Expansion ratio (g of H₂O / g polymer</td>

<td> 0,20</td><td> 3,66</td><td> 0, 92</td><td> 19,00</td>

<td> 0,33</td><td> 4,12</td><td> 1,36</td><td> 6, 00</td>

<td> 0,50</td><td> 4,20</td><td> 1,62</td><td> 4,00</td>

<td>Renagel</td><td> 3,85</td><td> 1,40</td><td> 9,00</td>

These data indicate that a higher ratio of amine to water resulted in a lower expansion ratio and was accompanied by a higher chelating capacity in the GI simulant. Similar tests can be performed routinely for other monomers and crosslinkers using this polymerization protocol to determine what is the ratio that provides the desired results for the particular use that will be given to the polymer.

Example 11

Measurement of the level of interference in chelation

This Example illustrates the measurement of chelation interference using a polymer of the invention and, as a comparison, a prior art polymer. A cross-linked polyamine material (EC172A) was prepared according to the protocol described in Example 4, with a BTA: ECH molar ratio of 2.5 and a ratio (BTA + ECH) to water of 1.73. His interference in chelation was compared to that of Renagel.

The "degree of chelation interference" or "chelation interference", as used in the present application, refers to the percentage reduction in chelating ability relative to the target ion observed between chelation experiments in a non-buffer. interfering agent and in a gastrointestinal (GI) simulant, at the same concentration of the target anion at equilibrium. First, an isotherm of chelation was obtained in a non-interfering buffer by plotting chelation capacity versus phosphate concentration at equilibrium for a variety of phosphate concentrations. The isotherm was then adjusted by an exponential function to predict the chelating capacity at any phosphate concentration. The chelation capacity measured in the GI simulant on the same isotherm was then represented by placing in the graph the point that represents the phosphate concentration with respect to the phosphate chelation at equilibrium for the GI simulant and drawing a vertical line through this point to intersect the non-interfering isotherm. The degree of interference was then calculated as (CQNI-CQGI) / CQNI * 100.

Chelation interference for EC172A is shown in the Table below and in Figure 3.

<td>Pinicial (mM)</td><td>Small (mM)</td><td>CQ (mmol / g)</td><td>CQ Predicted (mmol / g)</td><td>Interference (%)</td>

<td> 6,25</td><td> 3,31</td><td> 1,18</td><td> 2,17</td><td> 45, 7</td>

<td> 6,25</td><td> 3,28</td><td> 1,19</td><td> 2,16</td><td> 45, 0</td>

<td> 6,25</td><td> 3,24</td><td> 1,21</td><td> 2,15</td><td> 44,0</td>

ES 2 330 693 T3

Renagel chelation interference is shown in the Table below and in Figure 4.

<td>Initial p (mM)</td><td>P eq (mM)</td><td>CQ (mmol / g)</td><td>CQ Predicted (mmol / g)</td><td>Interference (%)</td>

<td> 6,25</td><td> 2,70</td><td> 1,42</td><td> 4,53</td><td> 68,7</td>

<td> 6,25</td><td> 2,54</td><td> 1,48</td><td> 4,46</td><td> 66, 7</td>

The chelation interference of EC172AEC172A is approximately 34% lower than that of Renagel.

Example 12

Ion chelation properties in ex vivo human aspirates

A cross-linked polyamine material (EC172A) was prepared according to the protocol described in Example 4, with a BtA: ECH molar ratio of 2.5 and a ratio (BTA + ECH) to water of 1.73. The phosphate chelating capacity of this material was then analyzed in a human aspirate obtained as in Example 1.

The phosphate chelation of EC172A was compared to that of the cross-linked polyallylamine active ingredient isolated from Renagel (Genzyme). The EC172A shows a much lower level of interference, as well as a much lower expansion index (2.5 vs 9 for Renagel)

<td></td><td>P^r eq Average (mM)</td><td>SD (mM)</td><td>CQ Average (mmol / g)</td><td>SD (mM)</td><td>CQ Predicted (mmol / g)</td><td>oo Interference</td>

<td>PFAA Renagel</td><td> 2,37</td><td> 0,01</td><td> 1,32</td><td> 0,00</td><td> 4,37</td><td> 70</td>

<td>EC172A</td><td> 1,55</td><td> 0,04</td><td> 1,64</td><td> 0,02</td><td> 1,68</td><td> 2,5</td>

In another experiment, both materials, EC172A and Renagel, were used in a different ex vivo human aspirate to quantify the degree of interference in phosphate chelation produced by competing solutes such as citrate anions and bile acids. Citrate anions and bile acids were titrated by ion chromatography and enzymatic assays respectively. The data shown below (average of six volunteers) indicates that the polymer of the present invention exhibits much better overall phosphate selectivity and chelation.

<td rowspan="2"></td><td>[PO4]</td><td>CQ (PO4)</td><td>[citrate]</td><td>CQ (citrate)</td><td>(Bile acid)</td><td>CQ (Bile)</td>

<td>mM</td><td>mmol / g</td><td>mM</td><td>mmol / g</td><td>mM</td><td>mmol / g</td>

<td>Control (without polymer)</td><td> 5,722</td><td></td><td> 1,667</td><td></td><td> 4,928</td><td></td>

<td>Renagel</td><td> 3,019</td><td> 1,078</td><td> 0,596</td><td> 0,429</td><td> 1,32</td><td> 1,443</td>

<td>EC172A</td><td> 1,78</td><td> 1,573</td><td> 1,316</td><td> 0,141</td><td> 4,65</td><td> 0,109</td>

ES 2 330 693 T3

Example 13

Measurement of gel porosity using the solute partition technique

This Example illustrates the measurement of gel porosity. These measurements were carried out with a polymer of the invention and with a commercially available phosphate chelating polymer for comparison purposes. As polymer of the invention, a cross-linked polyamine material (EC172A) was prepared according to the protocol described in Example 10, with a BTA: ECH molar ratio of 2.5 and a ratio of (BTA + ECH) to water of 1. 73. For comparison, the same porosity measurements were carried out with Renagel.

The probes were 8 polyethylene glycols (PEG) with a MW from 200 to 20,000 Da, and 4 polyethylene oxides (PEO) (30,000 to 230,000 Da).

All probes were dissolved in 30 mM of ammonium acetate buffer pH 5.5 (concentration 5 g / l). The probe solutions were added to a bath of EC172A in HCl (5 ml / g) and Renagel in HCl (dry gel 15 ml / g) previously measured; then they were stirred for 4 days in a Vortexer equipment.

The probe solutions were diluted 10x before CL analysis using a Polymer Lab Evaporative Light Scattering Detector (to be in the linear range of the detector that guarantees that the peak area ratio is equal to the concentration weight ratio).

Calculating the volume not accessible Volume = m_sw+ [1-c_before/ c_after] m_solv, where M_sw amount of water absorbed by the gel [g / g of dry gel] m_solv amount of water in which the probe was dissolved at the beginning [g / g dry gel] c_beforeand c_after: probe concentrations before and after equilibrium. The ratio c_before/ c_after is equal to the peak area ratio obtained by LC analysis.

The results of this Comparative Example are shown in Figures 5 and 6; Figure 5 illustrates the results in terms of molecular weight, while Figure 6 illustrates the results in terms of solute size. EC172A shows constant molecular exclusion for solutes down to MW as low as 200, compared to Renagel, which shows reduced exclusion for MW as high as 1000.

Example 14

Subsequent modification of the granules with chloropropylamine hydrochloride

Preparation of the standard solution • Chloropropylamine hydrochloride (B-SM-34-A) in water at 50% by weight - d = 1.132 • Sodium hydroxide in water at 30% by weight (by diluting a 50% solution in weight) - d = 1,335

Synthesis

FR-0005-144, a phosphate chelating polymer prepared according to Example 9 with a BTA: ECH molar ratio of 2.5, and a ratio (BTA + ECH) to water of 1.73 was used as a substrate for a subsequent amination. The FR-0005-144 granules were transferred to 4 ml vials (two 4x6 trays each containing 21 vials) and water, chloropropylamine, a standard hydrochloride solution and a standard sodium hydroxide solution were added using a liquid dispensing robot. The vials were sealed with a cap and the trays were mounted in reactors equipped with an individual heating and stirring system.

Heating and stirring were switched on for 12 hours: The reactor temperature was set at 85 ° C and the stirring speed at 1200 rpm.

Purification

Each of the materials was transferred to disposable culture tubes (16x100 mm), washed once with methanol, twice with a 1M hydrochloric acid solution in water, and three times with water. The granules were separated each time by centrifugation.

They were then dried in a lyophilizer and their titer was analyzed as digested food, non-interfering buffer and expansion ratio. The results are shown below in Table 12 and in Figure 7.

ES 2 330 693 T3

TABLE 12

Characteristics of the polymers prepared by subsequent modification of the granules with chloropropylamine hydrochloride

<td>FR- 0005- 144</td><td>Water</td><td>B-SM- 34-A</td><td>NaOH</td><td>Ratio in i weight B-SM- 3 4-A vs ΝΕ- Ο 005- 144</td><td>Mole ratio NaOH (vs B-SM- 3. 4- GIVES)</td><td>CQ Screen AD (mmol / g)</td><td>1 CQ Screen NEITHER (mmol / g)</td><td>Expansion ratio (g of H₂O / g of polymer</td>

<td> 222,.1</td><td> 864,5</td><td> 22,2</td><td> 1,71</td><td> 0,1</td><td> 0,25</td><td> 0, 94</td><td> 2,84</td><td> 2,91</td>

<td> 233,3</td><td> 883,0</td><td> 46,7</td><td> 3,59</td><td> 0,2</td><td> 0,25</td><td> 0,91</td><td> 2,94</td><td> 2,69</td>

<td> 203,7</td><td> 749, 0</td><td> 61,1</td><td> 4,70</td><td> 0, 3</td><td> 0,25</td><td> 0, 95</td><td> 2,85</td><td> 2,83</td>

<td> 209,1</td><td> 746, 3</td><td> 83,6</td><td> 6,43</td><td> 0,4</td><td> 0,25</td><td> 0,97</td><td> 2, 91</td><td> 2,64</td>

<td> 209</td><td> 723,5</td><td> 104,5</td><td> 8,04</td><td> 0,5</td><td> 0,25</td><td> 0,97</td><td> 2.89</td><td> 2,58</td>

<td>iiilll</td><td> 0. 0</td><td>llllill</td><td>lililí</td><td></td><td></td><td>ilo li lilll Aói8 |? lig ·</td><td>iSIlilllilllllS</td><td></td>

<td> 227</td><td> 7 61,3</td><td> 136,2</td><td> 10, 48</td><td> 0,6</td><td> 0,25</td><td> 0,96</td><td> 2,90</td><td> 2,60</td>

<td> 235</td><td> 7 62,8</td><td> 164,5</td><td> 12,65</td><td> 0,7</td><td> 0,25</td><td> 1,00</td><td> 2,97</td><td> 2,67</td>

<td> 231,3</td><td> 725, 9</td><td> 185,0</td><td> 14,23</td><td> 0,8</td><td> 0,25</td><td> 0,99</td><td> 2,88</td><td> 2,86</td>

<td> 278,5</td><td> 844 ,1</td><td> 2.50,7</td><td> 19,28</td><td> 0,9</td><td> 0,25</td><td> 0,99</td><td> 2,90</td><td> 3,38</td>

<td> 1 236,2</td><td> 690,4</td><td> 236,2</td><td> 18,1.7</td><td> 1,0</td><td> 0,25</td><td> 1,00</td><td> 2,96</td><td> 2,73 )</td>

<td>lililí</td><td>lilllll</td><td>llillll</td><td>lililí</td><td></td><td>Ri: 113ii || Ol | l</td><td>PRgttsjiS gAÓlgútapi g</td><td></td><td>loiililliilillliliiillii</td>

<td> ,</td><td></td><td></td><td> _ *</td><td></td><td>,,, X</td><td></td><td>x, vx</td><td> 2,85</td>

<td> 271</td><td> 1021,5</td><td> 54,2</td><td> 8,34</td><td> 0,2</td><td> 0,5</td><td> 0,95</td><td> 2,81</td><td> 2,74</td>

<td> 247</td><td> 902,5</td><td> 74,1</td><td> 11,40</td><td> 0,3</td><td> 0, 5</td><td> 0, 97</td><td> 2,85</td><td> 2,85</td>

<td> 225,5</td><td> 797,9</td><td> 90,2</td><td> 13,87</td><td> 0,4</td><td> 0,5</td><td> 0,97</td><td> 2,93</td><td> 2,61</td>

<td> 238,2</td><td> 815, 4</td><td> 119,1</td><td> 18,32</td><td> 0,5</td><td> 0, 5</td><td> 1,01</td><td> 2,84</td><td> 2,68</td>

<td> 270,7</td><td>lllillll</td><td>iilijiil</td><td>lililí</td><td></td><td>lililí</td><td> 0,89</td><td> 2,73</td><td> 2,98</td>

<td> 199,7</td><td> 660,5</td><td> 119,8</td><td> 18,43</td><td> 0,6</td><td> 0, 5</td><td> 0, 98</td><td> 2,91</td><td> 2,70</td>

<td> 230,6</td><td> 735, 1</td><td> 161,4</td><td> 2 4,83</td><td> 0,7</td><td> 0,5</td><td> 1,01</td><td> 3,03</td><td> 2,46</td>

<td> 221,3</td><td> 680, 9</td><td> 177,0</td><td> 27,23</td><td> 0,8</td><td> 0,5</td><td> 0, 98</td><td> 2,92</td><td> 2,58</td>

<td> 212,5</td><td> 629, 3</td><td> 191,3</td><td> 2 9,42</td><td> 0,9</td><td> 0,5</td><td> 1,02</td><td> 3,04</td><td> 2,61.</td>

<td> 200,4</td><td> 570,4</td><td> 200,4</td><td> 30,8 3</td><td> 1,0</td><td> 0,5</td><td> 1.,06</td><td> 2,93</td><td> 2.46</td>

<td>iiliil</td><td>lilllll</td><td>lilllll</td><td>lilllll</td><td>ililliiS</td><td></td><td></td><td></td><td></td>

<td> 213,1</td><td> 826,17</td><td> 21,3</td><td> 4,92</td><td> 0,1</td><td> 0, 7 5</td><td> -0,94</td><td> 2,80</td><td> • 2,92</td>

ES 2 330 693 T3

Example 15

Synthesis of cross-linked micrometer particles from phosphate using N, N '(tetra-3-aminopropyl) 1,4-diaminobutane / epichlorohydrin

The following standard solution was prepared: 1 molar equivalent of phosphoric acid (Aldrich, 85% by weight in water) was added to 1 molar equivalent of N, N '(tetra-3-aminopropyl) 1,4-diaminobutane over a 2 hour period. Water was then added to the solution until the resulting solution reached the following composition in percentages by weight: N, N '(tetra-3-aminopropyl) 1,4-diaminobutane 42% by weight, H₃PO₄ 13% by weight and water 45% by weight. The reactor contained 24 wells, used 5 ml flasks, and each flask contained a magnetic stir bar. 0.6-0.7 g of the prepared standard solution was placed in each flask. The agitators were turned on. The desired amount of pure epichlorohydrin was added to each vial. The reactor was heated to 60 ° C for 1 hour and then heated to 80 ° C for 8 hours. The reactor was allowed to cool. Water was added to each vial to swell the resulting gel. The gel was transferred to a 4x6 tray with 10 ml test tubes. The gel was then crushed into micrometer particles with a mechanical grinder (Brand: IKA. Model: Ultra-Turax T8). The particles were purified by removing water, washing with methanol and subsequently washing with a 20% NaOH solution. The gel particles were subsequently washed with 1.0 molar HCl, mixed for 30 minutes, and then the gel was allowed to stand and the supernatant liquid was decanted. This process was repeated 5 times to protonate the functionalized amine particle with chloride and replace the bound H3PO4. The gel particles were then washed with a 20% NaOH solution to deprotonate the functionalized amine particles. The gel particles were then washed twice with deionized water to remove excess NaOH / NaCl. The gel particles were freeze-dried for 3 days to produce a fine white powder. The synthesis is summarized in Table 13.

ES 2 330 693 T3

TABLE 13

Synthesis of gels that have been molecularly imprinted with phosphoric acid. ID 102776

<td>Row</td><td>Cabbage</td><td>B-SM- twenty- Torch (mg)</td><td>B-SM- 20-TeA (Moles)</td><td>Acid Phosphoric (mg)</td><td>Water (mg)</td><td>X-EP- 1 (mg)</td><td>X-EP-1 (Moles)</td><td>B- YE- twenty- Torch/ H3PO4</td><td>X- EP- 1 B- YE- twenty- Torch</td><td>Gel Present in well</td>

<td> 1.0</td><td> 1.0</td><td> 347,5</td><td> 0,0011</td><td> 107,7</td><td> 369, 8</td><td> 71,1</td><td> 0,0008</td><td> 1,0</td><td> 0,70</td><td>X</td>

<td> 1.0</td><td> 2.0</td><td> 339, 5</td><td> 0,0011</td><td> 105,2</td><td> 361,4</td><td> 79, 4</td><td> 0,0009</td><td> 1,0</td><td> 0, 80</td><td>X</td>

<td> 1.0</td><td> 3.0</td><td> 337,7</td><td> 0,0011</td><td> 104,6</td><td> 359, 4</td><td> 88,8</td><td> 0,0010</td><td> 1,0</td><td> 0, 90</td><td> ✓</td>

<td> 1.0</td><td> 4.0</td><td> 352, 1</td><td> 0,0011</td><td> 109, 1</td><td> 374,8</td><td> 102,9</td><td> 0,0011</td><td> 1,0</td><td> 1,00</td><td>z</td>

<td> 1.0</td><td> 5.0</td><td> 355, 4</td><td> 0,0011</td><td> 110, 1</td><td> 378,2</td><td> 114,3</td><td> 0,0012</td><td> 1,0</td><td> 1, 10</td><td> ✓</td>

<td> 1.0</td><td> 6.0</td><td> 366, 1</td><td> 0,0012</td><td> 113, 4</td><td> 389, 6</td><td> 128,4</td><td> 0,0014</td><td> 1,0</td><td> 1,20</td><td> ✓</td>

<td> 2.0</td><td> 1.0</td><td> 355,3</td><td> 0,0011</td><td> 110, 1</td><td> 378, 1</td><td> 135,0</td><td> 0,0015</td><td> 1,0</td><td> 1,30</td><td> ✓</td>

<td> 2.0</td><td> 2.0</td><td> 338,6</td><td> 0,0011</td><td> 104,9</td><td> 360,4</td><td> 138,6</td><td> 0,0015</td><td> 1,0</td><td> 1,40</td><td>z</td>

<td> 2.0</td><td> 3.0</td><td> 356,2</td><td> 0,0011</td><td> 110,4</td><td> 379, 1</td><td> 156,2</td><td> 0,0017</td><td> 1,0</td><td> 1,50</td><td> ✓</td>

<td> 2.0</td><td> 4.0</td><td> 349,7</td><td> 0,0011</td><td> 108,3</td><td> 372,2</td><td> 163, 5</td><td> 0,0018</td><td> 0, 99</td><td> 1, 61</td><td> ✓</td>

<td> 2.0</td><td> 5.0</td><td> 342,2</td><td> 0,0011</td><td> 106, 0</td><td> 364,2</td><td> 170, 0</td><td> 0,0018</td><td> 1,0</td><td> 1,70</td><td>z</td>

<td> 2.0</td><td> 6.0</td><td> 351,4</td><td> 0,0011</td><td> 108, 9</td><td> 374,1</td><td> 184,9</td><td> 0,0020</td><td> 1,0</td><td> 1,80</td><td>z</td>

<td> 3.0</td><td> 1.0</td><td> 364,1</td><td> 0,0012</td><td> 112,8</td><td> 387,5</td><td> 212,8</td><td> 0,0023</td><td> 1,0</td><td> 2,00</td><td> ✓</td>

<td> 3.0</td><td> 2.0</td><td> 351,2</td><td> 0,0011</td><td> 108, 8</td><td> 373, 8</td><td> 246, 4</td><td> 0,0027</td><td> 1,0</td><td> 2,40</td><td>z</td>

<td> 3.0</td><td> 3.0</td><td> 358,3</td><td> 0,0011</td><td> 111,0</td><td> 381,4</td><td> 293,2</td><td> 0,0032</td><td> 1,0</td><td> 2,81</td><td>z</td>

<td> 3.0</td><td> 4.0</td><td> 340,2</td><td> 0,0011</td><td> 105, 4</td><td> 362,1</td><td> 318,2</td><td> 0,0034</td><td> 1,0</td><td> 3,20</td><td>z</td>

<td> 3.0</td><td> 5.0</td><td> 368,9</td><td> 0,0012</td><td> 114,3</td><td> 392, 6</td><td> 388,2</td><td> 0,0042</td><td> 1,0</td><td> 3,59</td><td>z</td>

<td> 3.0</td><td> 6.0</td><td> 360, 5</td><td> 0,0011</td><td> 111,7</td><td> 383,7</td><td> 421,5</td><td> 0,0046</td><td> 1,0</td><td> 4,00</td><td>z</td>

<td> 4.0</td><td> 1.0</td><td> 345, 3</td><td> 0,0011</td><td> 107,0</td><td> 367,5</td><td> 444,0</td><td> 0,0048</td><td> 1,0</td><td> 4,40</td><td>z</td>

<td> 4.0</td><td> 2.0</td><td> 364,0</td><td> 0,0012</td><td> 112,8</td><td> 387,4</td><td> 510,7</td><td> 0,0055</td><td> 1,0</td><td> 4,80</td><td>z</td>

<td> 4.0</td><td> 3.0</td><td> 351,2</td><td> 0,0011</td><td> 108, 8</td><td> 373, 7</td><td> 533,7</td><td> 0,0058</td><td> 1,0</td><td> 5,20</td><td>z</td>

<td> 4.0</td><td> 4.0</td><td> 365, 5</td><td> 0,0012</td><td> 113,2</td><td> 389,0</td><td> 598,3</td><td> 0,0065</td><td> 0, 99</td><td> 5, 63</td><td>z</td>

<td> 4.0</td><td> 5.0</td><td> 368, 5</td><td> 0,0011</td><td> 111,1</td><td> 381,6</td><td> 628, 8</td><td> 0,0068</td><td> 1,0</td><td> 6, 02</td><td>z</td>

Polymers synthesized as described above chelate phosphate.

Although preferred embodiments of the present invention have been shown and described in the present application, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described in the present application may be employed in practicing the invention. The purpose of the following claims is to define the scope of the invention and which methods and structures within the scope of these claims and their equivalents are covered by the claims.

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A list of additional embodiments of the invention follows.

Embodiment 1. An anion chelating polymer, where the polymer chelates a target anion, and where said polymer is characterized by at least two of the following attributes:

a) an expansion ratio of less than about 5;

b) less than about 20% of the weight of the gel accessible to non-interacting solutes of molecular weight greater than about twice the MW of the target anion when said percentage is determined in a physiological environment; Y

c) an interference in ion chelation relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer.

Embodiment 2. The polymer with the attributes of embodiment 1, where said polymer chelates bile acids or citrate with a capacity less than 2 mmol / g.

Embodiment 3. The polymer with the attributes of embodiment 1, where the expansion ratio is measured in an isotonic solution and / or neutral pH.

Embodiment 4. The polymer with the attributes of embodiment 1, where the polymer comprises amine groups.

Embodiment 5. The polymer with the attributes of embodiment 4, where the amine monomers are chosen from the group consisting of allylamine, vinylamine, ethyleneimine, Formula 1 and Formula 2, where Formula 1 and Formula 2 are the following structures:

<img file="ES2330693T3_D0031.tif" />

Embodiment 6. The polymer with the attributes of embodiment 1, where the amine monomers and non-polymeric amine monomers are chosen from the group consisting of 1,3 diaminopropane, and N, N, N ', N'- tetrakis (3-aminopropyl) 1,4 diaminobutane, 1,2,3,4 tetra-aminobutane.

Embodiment 7. The polymer with the attributes of embodiment 1, where the polymer comprises a non-polymeric amine monomer and a crosslinker.

Embodiment 8. The polymer with the attributes of embodiment 1, where the crosslinking agent is present in an amount greater than 50% by moles of the total amine content of the monomers.

Embodiment 9. An anion chelating polymer comprising a non-polymeric amine monomer and a crosslinker. Where the polymer is obtained by a heterogeneous method and the expansion ratio of the polymer is less than 5.

Embodiment 10. A pharmaceutical composition comprising the polymer with the attributes of embodiment 1 to 9, and a pharmaceutically acceptable excipient.

Embodiment 11. The composition with the attributes of embodiment 1 where the target anion is chosen from the group consisting of phosphate and oxalate.

Embodiment 12. The composition with the attributes of Embodiment 1 where the target anion is phosphate.

Embodiment 13. An anion chelating polymer comprising a non-polymeric amine monomer and a crosslinker, where the polymer is characterized by at least one of the following attributes:

a) an expansion ratio of less than about 5;

ES 2 330 693 T3

b) less than about 20% of the weight of the gel accessible to non-interacting solutes of molecular weight greater than about 200, when said percentage is determined in a physiological environment; Y

c) an interference in ion chelation relative to phosphate of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer.

Embodiment 14. A phosphate chelating polymer comprising a non-polymeric amine monomer and a crosslinker, wherein said polymer is characterized by at least one of the following attributes:

a) an expansion ratio of less than about 5;

b) less than about 20% of the weight of the gel accessible to non-interacting solutes of molecular weight greater than about 200, when said percentage is determined in a physiological environment; Y

c) an interference in ion chelation relative to phosphate of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer.

Embodiment 15. A phosphate chelating polymer 4, wherein said polymer is characterized by at least one of the following attributes:

a) less than about 20% of the weight of the gel accessible to non-interacting solutes of molecular weight greater than about 200, when said percentage is determined in a physiological environment; Y

b) an interference in ion chelation relative to phosphate of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer.

Embodiment 16. The polymer with the attributes of embodiment 15, where the polymer comprises non-polymeric amine monomers and a crosslinking agent, wherein the crosslinking agent is present in an amount greater than 50% by mole of the total amine content of monomers.

Embodiment 17. The polymer with the attributes of embodiment 14, where said polymer chelates bile acids or citrate with a capacity less than 2 mmol / g.

Embodiment 18. The polymer with the attributes of embodiment 14, where the expansion ratio is measured in an isotonic solution and / or physiological pH.

Embodiment 19. The polymer with the attributes of embodiment 15, where said polymer has a chelating capacity greater than about 0.5 mol / g.

Embodiment 20. The polymer with the attributes of embodiment 15, where said polymer is a polyimine polymer, and where the chloride content of the polymer is less than about 35% by mole of the amine group content.

Method of realization 21. The polymer with the attributes of embodiment 1 comprising one or more amine monomers and one or more crosslinkers, where the polymer is produced by a method in which the amine is in the solvent prior to crosslinking in a ratio of amine: solvent from about 3: 1 to about 1: 3 and the total content of crosslinkers added to the reaction mixture is such that the average number of connections to the amine monomers (NC) is between about 2.05 and about 6.

Embodiment 22. The composition with the attributes of embodiment 21 where the total content of crosslinkers added to the mixture is such that NC is between about 2.2 and about 4.5.

Embodiment 23. The polymer with the attributes of Embodiment 1 produced by a method wherein the target anion is present during the crosslinking reaction.

Embodiment 24. The polymer with the attributes of embodiment 1, where the crosslinking reaction comprises the steps of:

a) adding the amine monomer as a free base and adding the target anion in its acid form;

b) adding a crosslinking agent;

c) carrying out the crosslinking reaction, and

d) washing away the target ion.

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Embodiment 25. The polymer with the attributes of embodiment 1, where the polymer is produced by a method that comprises

a) forming a soluble prepolymer (i) by adding the amine monomer, and then (ii) adding a fraction of the crosslinking agent to form a syrup;

b) emulsifying the syrup in oil; Y

c) adding the remaining fraction of the crosslinker to form crosslinked granules.

Embodiment 26. The polymer with the attributes of embodiment 1 comprising one or more amine monomers and one or more crosslinkers, where the polymer is produced by a method that comprises

a) carrying out a first reaction between an amine monomer and a crosslinker to form a gel;

b) reacting the gel with an alkylamino halide, where an alkylamino group is chemically attached to the gel by substitution of the halide.

Embodiment 27. A pharmaceutical composition comprising the polymer with the attributes of Embodiment 21 and a pharmaceutically acceptable excipient.

Embodiment 28. The polymer with the attributes of embodiment 1, where the polymer is in the form of particles, and where the polymer particles are covered by an outer shell.

Embodiment 29. An ion chelating polymer comprising one or more amine monomers and one or more crosslinkers where the polymer is produced by a method where the content of crosslinkers added to the reaction mixture is such that the average number of connections with amine monomers it is between about 2.2 and about 4.5.

Embodiment 30. The polymer with the attributes of embodiment 29, where the amine monomer is chosen from the group consisting of 1,3-diaminopropane, and N, N, N ', N'-tetrakis (3-aminopropyl) 1 , 4-diaminobutane, 1,2,3,4 tetra-aminobutane, and where the crosslinking agent is chosen from the group consisting of 1,3-dichloropropane and epichlorohydrin.

Embodiment 31. A pharmaceutical composition comprising the polymer with the attributes of embodiment 29 and a pharmaceutically acceptable excipient.

Embodiment 32. An ion chelating polymer comprising N, N, N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane, 1,2,3,4 tetra-aminobutane cross-linked with epichlorohydrin where the polymer is produced by a method where the initial concentration ratio of N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane, 1,2,3,4 tetraaminobutane to water is from about 1: 3 to about 1: 4 .

Embodiment 33. The polymer with the attributes of embodiment 32, where the initial concentration ratio of N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane, 1,2,3,4 tetra-aminobutane The water is about 1.5: 1 to about 4: 1.

Embodiment 34. A pharmaceutical composition comprising the polymer with the attributes of Embodiment 32 and a pharmaceutically acceptable excipient.

Embodiment 35. A phosphate chelating polymer comprising N, N, N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane, 1,2,3,4 tetra-aminobutane and the crosslinking agent epichlorohydrin where the crosslinking agent Epichlorohydrin added to the reaction mixture is between about 200% and about 300% of the total content in N ', N'tetrakis (3-aminopropyl) 1,4 diaminobutane, 1,2,3,4 tetra-aminobutane.

Embodiment 36. The polymer with the attributes of embodiment 35, where where the polymer is produced by a method where the ratio of monomers to water in the initial reaction mixture is between about 3: 1 and about 1: 1 .

Embodiment 37. The polymer with the attributes of embodiment 35, where the total epichlorohydrin crosslinker added to the reaction mixture is between about 230 and about 270% of the total content of N ', N'-tetrakis (3-aminopropyl ) 1,4 diaminobutane, 1,2,3,4 tetra-aminobutane.

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Embodiment 38. The polymer with the attributes of Embodiment 35, where the total epichlorohydrin crosslinker added to the initial reaction mixture is approximately 250 mol% of the total content of

N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane, 1,2,3,4 tetra-aminobutane.

Embodiment 39. The polymer with the attributes of embodiment 38, produced by a method where the ratio of (N ', N'-tetrakis (3-aminopropyl) 1,4 diaminobutane, 1,2,3,4 tetra-aminobutane + epichlorohydrin) to water is about 1.73: 1.

Embodiment 40. The polymer with the attributes of embodiment 35, where the polymer is in the form of hemispherical beads.

Embodiment 41. A phosphate chelating polymer comprising polyallylamine monomers and crosslinking epichlorohydrin, wherein the polymer is produced by dissolving the polyallylamine monomers in a monomer to water ratio of about 3: 1 to about 1: 3.

Embodiment 42. The polymer with the attributes of Embodiment 41, where the total epichlorohydrin crosslinker added to the reaction mixture is approximately 10 mol% of the polyallylamine content.

Embodiment 43. A phosphate chelating polymer comprising a 1,3-diaminopropane crosslinker in a molar ratio of approximately 1: 1, where the prepolymer is further crosslinked by the epichlorohydrin crosslinker added to the reaction mixture is approximately 1 , 1: 1 to approximately 1.7: 1.

Embodiment 44. A pharmaceutical composition comprising the polymer with the attributes of Embodiment 10, 24, 31, or 34 is a liquid formulation comprising water and pharmaceutically acceptable excipients.

Embodiment 45. A pharmaceutical composition comprising the anion chelating polymer that binds a target anion and one or more pharmaceutically acceptable excipients, where the composition is in the form of a chewable or disintegrable tablet in the mouth, and where the polymer has a rate of dilation during the time necessary to travel through the oral cavity and esophagus less than approximately 5.

Embodiment 46. A pharmaceutical composition comprising the anion chelating polymer that binds a target anion and one or more pharmaceutically acceptable excipients, where the composition is in the form of a chewable or disintegrable tablet in the mouth, and where the polymer has the following: following attributes:

a) less than about 20% of the weight of the gel accessible to non-interacting solutes of molecular weight greater than about 200, when said percentage is determined in a physiological environment; Y

b) an interference in ion chelation relative to phosphate of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer.

Embodiment 47. The composition with the attributes of embodiment 46 where the polymer has a transition temperature greater than 50 ° C.

Embodiment 48. The composition with the attributes of embodiment 46 where the excipients are chosen from the group consisting of sucrose, mannitol, xylitol, maltodextrin, fructose, sorbitol and combinations thereof, and where the composition is produced by a method wherein the polymer is pre-formulated with said excipient to form a solid solution.

Embodiment 49. The composition with the attributes of embodiment 46 where the target anion of the polymer is phosphate.

Embodiment 50. The composition with the attributes of embodiment 46 where the polymer chelates an ion in vivo with a chelating capacity greater than 0.5 mmol / g.

Embodiment 51. The composition with the attributes of Embodiment 46 where the in vivo anion chelating polymer comprises greater than about 50% by weight of the tablet.

Embodiment 52. The composition with the attributes of embodiment 46 where the tablet is cylindrical in shape with a diameter of about 22mm and a height of about 4mm and the anion chelating polymer comprises more than about 1.6g.

Embodiment 53. The pharmaceutical composition with the attributes of embodiment 46 where the excipients are chosen from the group consisting of sweetening agents, binders, lubricants, and disintegrants.

Embodiment 54. The pharmaceutical composition with the attributes of Embodiment 53 where the polymer is present in particles less than about 40 µm in mean diameter.

ES 2 330 693 T3

Embodiment 55. The pharmaceutical composition with the attributes of embodiment 53 where the sweetening agent is chosen from the group consisting of sucrose, mannitol, xylitol, maltodextrin, fructose, and sorbitol, and combinations thereof.

Embodiment 56. A method of measuring interference in target ion chelation for an ion chelating polymer by:

a) adding the ion chelating polymer to a non-interfering buffer containing the target ion and measuring the ability of the polymer to chelate the target ion;

b) making an interfering buffer by artificially digesting a standardized food with mammalian GI enzymes and / or aspirating chyme from the upper gastrointestinal tract of mammals that have ingested said standardized food, where the standardized food contains the target ion;

c) adding the ion chelating polymer to the interfering buffer and measuring the chelating capacity of the target ion, where said capacity is obtained from the difference between the concentration of target ions in the interfering buffer before and after incorporation of the chelating polymer ion; Y

d) calculating the degree of interference in chelation, as the ratio of decrease in the chelating capacity of the target ion observed between the measurement of chelation in a non-interfering buffer and in the interfering buffer at the same equilibrium ion concentration.

Embodiment 57. A method for choosing an ion chelating polymer that chelates a target ion, said polymer comprising monomer and crosslinking, wherein said polymer is characterized by at least one of the following attributes:

a) an expansion ratio of less than about 5;

b) less than about 20% of the weight of the gel accessible to non-interacting solutes of molecular weight greater than about twice the MW of the target anion when said percentage is determined in a physiological environment; Y

c) an interference in ion chelation relative to the target anion of less than approximately 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer, said method comprising:

i) vary:

1) the ratio of crosslinker to monomer;

2) the ratio of (monomer + crosslinker) to solvent in the reaction medium;

3) the net charge of the polymer at physiological pH and tonicity; me

4) the hydrophilic / hydrophobic balance of the polymer backbone;

ii) evaluating the swelling capacity, porosity and interference in ion chelation of the resulting polymer; and iii) choosing a polymer that has at least one of said characteristics.

Embodiment 58. A method for improving the therapeutic properties and / or the suitability for administration and / or the pharmaceutical properties of a polyamine polymer, comprising at least one of the following steps:

a) crosslinking said polymer with a crosslinking agent, so that the average number of connections with the polyamine monomer is between about 2.05 and about 6; me

b) producing said polymer through a process where the polyamine is initially present in water in a polyamine: water ratio of from about 3: 1 to about 1: 3.

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Embodiment 59. A method for manufacturing an anion chelating polymer that comprises combining an amine monomer with a crosslinking agent through a heterogeneous process, and wherein the phosphate chelating polymer is characterized by at least two of the following attributes:

a) an expansion ratio of less than about 5;

b) less than about 20% of the weight of the gel accessible to non-interacting solutes of molecular weight greater than about twice the MW of the target anion when said percentage is determined in a physiological environment; Y

c) an interference in ion chelation relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer.

Embodiment 60. The method with the attributes of embodiment 59, where the amine monomer is a non-polymeric amine monomer.

Embodiment 61. The method with the attributes of embodiment 59, where the polymer comprises amine monomers and a crosslinker, where the amount of crosslinker is present in an amount that is greater than 50% by mole of the total content of amine monomers.

Embodiment 62. The method with the attributes of embodiment 59, where the amine monomer is a polyallylamine.

Embodiment 63. The method with the attributes of embodiment 59, where the crosslinking agent is epichlorohydrin.

Embodiment 64. An anion chelating polymer that chelates a target ion, where the polymer is produced by crosslinking an amine monomer with a crosslinking agent through a heterogeneous process, and where the polymer is characterized by at least two of the following attributes:

a) an expansion ratio of less than about 5;

b) less than about 20% of the weight of the gel accessible to non-interacting solutes of molecular weight greater than about twice the MW of the target anion when said percentage is determined in a physiological environment; Y

c) an interference in ion chelation relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer.

Embodiment 65. The polymer with the attributes of embodiment 64 where the amine monomer is a non-polymeric amine monomer.

Embodiment 66. The polymer with the attributes of embodiment 64, where the polymer comprises amine monomers and cross-linker, where the cross-linker is present in an amount that is greater than 50% by mole of the total content of amine monomers .

Embodiment 67. The polymer with the attributes of embodiment 64 where the amine monomer is a polyallylamine.

Embodiment 68. The polymer with the attributes of embodiment 64 where polyallylamine is crosslinked with epichlorohydrin.

Embodiment 69. A method of removing the anion from an animal, comprising administering an effective amount of a polymer to the animal, wherein the polymer is an anion-chelating polymer that chelates a target anion, and wherein said polymer is characterized by al minus two of the following attributes:

a) an expansion ratio of less than about 5;

b) less than about 20% of the weight of the gel accessible to non-interacting solutes of molecular weight greater than about twice the MW of the target anion when said percentage is determined in a physiological environment; Y

c) an interference in ion chelation relative to the target anion of less than about 60% when measured in a gastrointestinal simulant, relative to a non-interfering buffer.

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Embodiment 70. The method with the attributes of embodiment 69, where the polymer comprises a non-polymeric amine monomer and a crosslinker.

Embodiment 71. The method with the attributes of embodiment 69, where the polymer comprises amine monomers and crosslinker, where the crosslinker is present in an amount that is greater than 50% by mole of the total content of amine monomers .

Embodiment 72. The method with the attributes of embodiment 69, where the anion is phosphate.

Method of realization 73. The method with the attributes of way of realization 69, where the animal suffers at least one disease chosen from the group formed by those of the group formed by hyperphosphatemia, hypocalcemia, hyperthyroidism, depressed renal synthesis of calcitrol, tetany due to hypocalcemia , renal failure, ectopic calcification of soft tissues and ERT.

Embodiment 74. The method with the attributes of embodiment 72 where the animal is a human.

Embodiment 75. The method with the attributes of embodiment 72 where said phosphate is eliminated from the gastrointestinal tract.

Embodiment 76. The method with the attributes of embodiment 72 where said administration is oral.

Embodiment 77. The method with the attributes of embodiment 72 where said polymer is administered in conjunction with at least one of proton pump inhibitors, calcimimetics, vitamins and analogs thereof, or a phosphate chelator.

Embodiment 78. The method with the attributes of embodiment 77 where the phosphate chelator is at least one of aluminum carbonate, calcium carbonate, calcium acetate, lanthanum carbonate or SEVELAMER hydrochloride.