Compounds and compositions for delivering active agents

Description of the invention

The invention relates to compounds, pharmaceutical compositions containing them, and unit dosage forms. The compounds are suitable for the formation of non-covalent mixtures with the active agents for administration to animals orally, rectally or by other routes.

Conventional means for the delivery of active agents are often severely limited by biological, chemical, and physical barriers. These barriers are typically imposed by the environment through which delivery occurs, the environment associated with the delivery target, and / or the target itself. Such barriers are particularly limited by active biological or chemical agents.

When delivering biologically and chemically active pharmacological and therapeutic agents to animals, these barriers are imposed by the body. Examples of physical barriers are the skin, lipid bilayers, and the membranes of various organs, which are relatively impermeable to some active agents but must be overcome before an end, such as the circulatory system, is achieved. Chemical barriers include, but are not limited to, differences in pH in the gastrointestinal (GI) tract and degrading enzymes.

These barriers are especially important when designing oral delivery systems. In the absence of biological, chemical, and physical barriers, oral delivery could be the route of choice for administering many biologically or chemically active agents to animals. Among the many agents that are usually unsuitable for oral administration, mention may be made of biologically or chemically active peptides such as calcitonin and insulin; polysaccharides, in particular mucopolysaccharides including, but not limited to, heparin, heparinoids; antibiotics; and other organic substances. These agents quickly become ineffective or are broken down in the gastrointestinal tract by acid hydrolysis, enzyme action, etc. In addition, the size and structure of macromolecular drugs can inhibit absorption.

Earlier routes of oral administration of pharmacological agents have involved the simultaneous administration of excipients (e.g., resorcinols and non-ionic surfactants such as polyoxyethylene oleyl ether and polyethylene n-hexadecyl ether) to artificially increase the permeability of the intestinal walls as well as simultaneous administration of enzyme inhibitors (e.g. pancreatic trypsin inhibitors, diisopropyl fluorophosphate (DFF) and trazylol) to inhibit enzymatic degradation. Liposomes have also been described as drug delivery systems for insulin and heparin. See, for example, U.S. Patent No. 4,239,754; Patel et al. (1976), FEBS Letters, Vol. 62, p. 60; and Hashimonoto et al. (1979), Endocrinology Japan, Vol. 26, p. 337. However, wide-ranging use of such drug delivery systems is excluded because: (1) these systems require toxic amounts of excipients or inhibitors; (2) suitable loads are not available, i.e. low molecular weight active agents, (3) the systems have poor stability and inadequate shelf life, (4) the systems are difficult to manufacture; (5) the systems do not provide protection for the active agent (charge); (6) the systems adversely alter the active agent; or (7) the systems do not allow or support the absorption of the active agent.

More recently, microspheres of artificial polymers of mixed amino acids (proteinoids) have been used to deliver pharmaceuticals. U.S. Patent No. 4,925,673 describes, for example, proteinoid compounds in the form of drug-containing microspheres, and methods for their preparation and use. Such proteinoid microspheres are useful for the delivery of many active agents. In addition, some modified amino acids can also be used to deliver pharmaceuticals. See, e.g., U.S. Patent Nos. 5,629,020; 5,643,957; 5,650,386 and 5,776,888.

However, there remains a need for simple, inexpensive delivery systems that can be readily manufactured and that can deliver multiple active agents in a variety of ways.

This task is fulfilled by the compounds of the invention which are useful for the delivery of active agents.

Structurally similar compounds and compositions for drug delivery are known from WO 96/30036 A1 and WO 98/34632 A1, but none of these documents disclose compounds of the invention.

The compounds of the invention include the following compounds selected from the group consisting of compounds of formula

PL 212 652 B1

<img file="PL212652B1_D0001.tif" />

X wherein n, m and X are as defined in the table below

<td>n</td><td>m</td><td>X</td><td>Relationship no</td>

<td> 7</td><td> 0</td><td>2-OH, 5-F</td><td> 54</td>

<td> 3</td><td> 0</td><td>2-OH, 5-Cl</td><td> 105</td>

<td> 4</td><td> 0</td><td>2-OH, 5-Cl</td><td> 116</td>

<td> 5</td><td> 0</td><td>2-OH, 5-Cl</td><td> 117</td>

<td> 6</td><td> 0</td><td>2-OH, 5-Cl</td><td> 118</td>

and their salts.

Also within the scope of the invention is a pharmaceutical composition which comprises (A) a biologically active agent selected from the group consisting of parathyroid hormone (PTH), heparin, growth hormones, calcitonin, and mixtures thereof; and (B) a compound selected from the group consisting of compounds of formula

<img file="PL212652B1_D0002.tif" />

wherein n, m and X are as defined above, their salts and mixtures. Compositions containing the compounds of the invention and the active agents are useful for delivering the active agents to selected biological systems and have increased or improved bioavailability compared to the bioavailability of the active agent administered alone.

A composition that comprises (A) a biologically active agent selected from the group consisting of parathyroid hormone (PTH), heparin, growth hormones, calcitonin, and mixtures thereof is preferred; and (B) a compound of formula

<img file="PL212652B1_D0003.tif" />

where n is 7, m is 0,

X is 2-OH, 5-F (54).

Also preferred is a composition which comprises a biologically active agent (A) as defined above and (B) a compound of formula

PL 212 652 B1

<img file="PL212652B1_D0004.tif" />

where n is 3, m is 0,

X is 2-OH, 5-Cl (105), or (B) a compound of formula

<img file="PL212652B1_D0005.tif" />

where n is the number 4, m is the number 0,

X is 2-OH, 5-Cl (116) or (B) a compound of formula

<img file="PL212652B1_D0006.tif" />

where n is the number 5, m is the number 0,

X is 2-OH, 5-Cl (117) or (B) a compound of formula

<img file="PL212652B1_D0007.tif" />

where n is the number 6, m is the number 0,

X is 2-OH, 5-Cl (118).

Compositions which contain the compounds of the invention Nos. 54, 105, 116, 117, 118, the structures of which are shown above, with parathyroid hormone as active ingredient, with either heparin or growth hormones or calcitonin, are preferred.

The invention also encompasses a unit dosage form which, in addition to the composition of the invention, also contains at least one of the ingredients listed in (a) to (g), including (a) an excipient, (b) a diluent, (c) a disintegrant, ( d) a lubricant, (e) a plasticizer, (f) a colorant, (g) a dose carrier.

The compounds of the invention may be in the form of the carboxylic acid and / or its salt. Salts include, but are not limited to, organic and inorganic salts such as sodium salts.

Many of the compounds described herein can be derived from amino acids and can be readily prepared from amino acids by methods known to those skilled in the art based on this disclosure.

And the methods described in WO 96/30036, WO 97/36480, US Patent Nos. 5,643,957 and US Patent Nos. 5,650,386. For example, compounds can be prepared by reacting a single amino acid with an appropriate acylating agent or amino modifying agent that reacts with a free amino residue present in the amino acid to form an amide. Protecting groups can be used to avoid undesired side reactions, as is known to those skilled in the art. Protective groups are described in TW Greene Protecting Groups in Organic Synthesis, Wiley, New York (19881).

The compound can be purified by recrystallization or fractionation over one or more solid chromatographic supports, or a combination of both methods can be used. Suitable solvent systems for recrystallization include, but are not limited to, acetonitrile, methanol, and tetrahydrofuran. The fractionation can be carried out by chromatography using a suitable support such as alumina and methanol / n-propanol mixtures as the mobile phase; reverse phase chromatography using trifluoroacetic acid / acetonitrile mixtures as the mobile phase; and by ion exchange chromatography, using water or an appropriate buffer as the mobile phase. When anion exchange chromatography is performed, a 0-500 mM sodium chloride gradient is preferably used.

Compositions of the invention can be prepared by mixing an aqueous solution of a compound of the invention with an aqueous solution of the active ingredient just prior to administration. Alternatively, the compound and the biologically or chemically active ingredient may be mixed during the manufacturing process.

The solutions may optionally contain additives such as phosphate salts as buffers, citric acid, glycols or other dispersing agents. Stabilizing additives may also be incorporated into the solution, preferably at a concentration ranging between about 0.1 and 20% (w / v).

The amount of active ingredient is an amount effective to achieve the purpose for which the active agent is intended. The amount of active ingredient in the composition will usually be a pharmacologically, biologically or therapeutically effective amount. However, when the composition is used in a unit dosage form such as a capsule, tablet, powder or liquid, the amount may be smaller as such form may contain a mixture of more than one active agent, or it may contain a pre-divided amount that is pharmacologically, biologically or therapeutically effective. . Thus, the total effective amount may be administered in cumulative doses containing, collectively, pharmacologically, biologically, or therapeutically effective amounts of the active agent.

The total amount of active agent to be used can be determined by those skilled in the art. However, since the compositions can deliver the active agents more effectively than heretofore, smaller amounts of the active agents can be used than the amounts used in current forms or delivery systems, while achieving the same blood levels and the same therapeutic effects.

The compounds of the invention deliver active agents, especially in systems for oral, nasal, sublingual, intraduodenal, subcutaneous, buccal, colonic, rectal, vaginal, mucosal, pulmonary, transdermal, intradermal, parenteral, intravenous, intramuscular and ocular administration systems. as well as by crossing the blood-brain barrier.

Dosage unit forms contain one or a combination of excipients, diluents, disintegrants, lubricants, plasticizers, colorants, aromatics, taste masking agents, sugars, sweeteners, salts, and carriers, including, but not limited to, water. , 1,2-propanediol, ethanol, olive oil or a combination thereof.

The compounds and compositions of the invention are useful for administering biologically active agents to animals, including, but not limited to, birds, such as chickens, mammals, such as cows, pigs, dogs, cats, primates, and especially humans. The system is particularly advantageous for delivering active agents that would otherwise degrade or become less effective under the conditions that the active agent encounters before reaching the target zone (i.e. the area where the active agent in the composition of the invention is to be released) and in the animal to which the agent is administered. The compounds and compositions of the invention are also useful for the administration of particularly active agents that cannot be delivered by a given route, especially oral, or agents for which improved delivery is desired. This delivery can be improved by delivering more active agent over a period of time or over a period of time (to obtain a faster delivery effect).

After administration, the active agent present in unit dose form is absorbed into the bloodstream. The bioavailability of an agent is readily determined by measuring the known pharmacological activity in the blood.

For example by the increase in blood clotting time caused by heparin, by the decrease of calcium levels in the bloodstream caused by calcitonin. Alternatively, blood levels of the active agent itself can be measured directly.

The following examples illustrate the invention without limiting its scope. All parts are by weight unless otherwise stated.

Example 1 - Preparation of 105

4-Bromobutyric acid (26.17 g, 0.16 mol) and a few drops of sulfuric acid were added to methanol (150 ml). This solution was heated to reflux for 3 1/4 hours. TLC (EtOAc / hexane, 1: 1) showed complete ester formation. The mixture was concentrated in vacuo to an oil. The oil was dissolved in methylene chloride and washed with water, saturated sodium bicarbonate, and brine. The organic layer was dried over sodium sulfate and concentrated in vacuo.

₁

20.26 g of methyl (4-bromo) butanoate, the structure of which was confirmed by the method, were obtained ¹H NMR.

6-chlorocarsalam (karsalam is (2H-1,3-benzoxazine-2,4 (3H) -dione) (12.4 g, 1.12 eq.), Methyl (4-bromo) butanoate (10.13 g, 1.0 eq.) And 10.13 g of sodium carbonate (10.13 g, 1.12 eq.) Were stirred in 50 mL of DMA. The solution was refluxed for 4.5 hours, then cooled to room temperature overnight. Water and 2N NaOH solution were added to the filtrate The mixture was heated for 2.5 hours HPLC indicated complete hydrolysis. The solution was acidified with concentrated HCl to pH = about 1. The resulting white solid was filtered and treated with P2O5 in vacuo overnight. The solid was recrystallized from methanol / water, filtered and dried, yielding 7.35 g of compound. CHN calculated for C 11 H 12 NO 4 Cl: C, 51.28; H, 4.69; N, 5.44; Found C, 50.92; H, 4.59; N, 5.46. Melting point: 136-140 ° C. It should be noted that for other batches of this compound prepared by the same process, which gave a purer product by elemental analysis, the melting points were in the range of 153-155 ° C.

Example 2: Preparation of compound 118

To a 250 mL three-necked round bottom flask containing 6-chlorocarsalam (10.0 g, 0.0506 mol) and dimethylacetamide (50 mL) was added sodium carbonate (5.37 g, 0.0506 mol). Ethyl 5-bromoheptanoate (10.91 g, 0.0460 mol) was added to the reaction mixture with stirring in one portion, and then the reaction mixture was heated and kept at 80 ° C for 16 hours. Heating was discontinued and the reaction mixture was cooled to room temperature. The mixture was then vacuum filtered and the filter cake washed with two 20 ml portions of ethyl alcohol. Water was added to the filtrate until precipitation of an orange-brown solid was observed. The material was isolated by vacuum filtration and washed first with 20 ml of ethyl alcohol and then with 20 ml of heptane. The solid was transferred to a round bottom flask and 200 mL of 2N NaOH was added. It was then refluxed for 1 hour, then cooled to 25 ° C and the reaction mixture acidified with 2N HCl solution. A white solid precipitated which was isolated by filtration, recrystallized from ethyl alcohol: water 30:70 and dried overnight in vacuo. 9.55 g (63.0%) of the product was isolated. Melting point: 115-116 ° C. Post-combustion analysis:% C: 59.09 (calculated), 55.93 (found); % H: 6.01 (calc.), 6.09 (found); % N: 4.67 (calculated), 4.64 (found). Analysis¹H NMR: (d6-DMSO): δ 12.7, s, 1H (COOH); δ 12.0, s, 1H (OH); δ 8.88, t, 1H (NH); δ 7.94, d, 1H (H ortho to the amide); δ 7.42; dd, 1H (H para versus amide); δ 6.92, d, 1H (H ortho to the hydroxide); δ 3.27, q, 2H, (CH2 alpha versus amide); δ 2.20, t, 2H (CH2 alpha versus COOH); δ 1.40, m, 4H (CH2 beta versus amide, CH2 beta versus COOH); δ 1.30, m, 4H (remaining aliphatic CH2).

Compounds 116 and 117 were also prepared by this method using the appropriate starting materials.

Example 3 Delivery of Heparin

An colonic delivery (IC) composition containing the delivery agent compound and USP sodium heparin in 25% aqueous propylene glycol was prepared by mixing. Either the sodium salt of the compound was used, or the free acid was converted to the sodium salt using one equivalent of sodium hydroxide (1.0 N). Generally, powdered compound and heparin are mixed, 25% aqueous propylene glycol and NaOH solution are added, sonicated and then diluted to 3.0 volume. The pH is checked and adjusted to 7-8 if necessary. The final amounts of compound and heparin per dose are given in Table 1 below.

Male Sprague-Dawley rats weighing 200-250 g were fasted for 24 hours and then administered ketamine (44 mg / kg) and chlorpromazine 15 minutes prior to drug administration.

PL 212 652 B1 (1.5 mg / kg). Fasting rats were given solutions at a dose of 1 ml / kg. Blood samples were taken by cardiac puncture and then ketamine (44 mg / kg) was administered. Heparin activity was determined using the partial thromboplastin activation time (APTT) according to the method of JB Henry, Clinical Diagnosis and Management by Laboratory Methods; Philadelphia, PA; WB Saunders (1979). The results are given in Table 1 below.

<td colspan="5">Table 1. Ophthalmic delivery of heparin</td>

<td>Relationship</td><td>Method of administration</td><td>Compound dose (mg / kg)</td><td>Heparin Dose (mg / kg)</td><td>Mean APTT Peak (sec)</td>

<td> 54</td><td>IC</td><td> 50</td><td> 25</td><td> 124±137</td>

Example 4 Oral Delivery of Recombinant Human Growth Hormone (rhGH)

A solution was prepared for oral gavage delivery (PO) of the delivery agent compound and rhGH in phosphate buffer. A solution of the compound was prepared with either the sodium salt of the compound or the free acid was salified by mixing and adding one equivalent of sodium hydroxide (1.0 N), followed by dilution with phosphate buffer. Final dosing solutions were prepared by mixing the compound solution with the stock solution. rhGH (usually at a concentration of 15 mg rhGH / ml) and dilution to the desired volume (usually 3.0 ml). Table 2 below lists the amounts of compound and rhGH per dose.

Male Sprague-Dawley rats weighing 200-250 g were fasted for 24 hours and then dosed with ketamine (44 mg / kg) and chlorpromazine (1.5 mg / kg) 15 minutes prior to drug administration. Rats were administered the solution in an amount of 1 ml / kg. Blood samples were serially drawn from the tail artery and the concentrations of rhGH were determined. Concentrations of rhGH were determined using an immunoassay kit (Kit # KIF4015 from Genzyme Corporation, Inc., Cambridge, MA).

The results are shown in Table 2 below.

<td colspan="5">Table 2. Oral delivery of rhGH to rats</td>

<td>Relationship</td><td>Method of administration</td><td>Compound dose (mg / kg)</td><td>RhGH dose (mg / kg)</td><td>Mean peak plasma rhGH (ng / ml)</td>

<td> 54</td><td>AFTER</td><td> 200</td><td> 3</td><td> 48 ± 33</td>

Example 5 Provision of Salmon Calcitonin (sCT)

Compositions for the oral (PO) delivery of the delivery agent compound and salmon calcitonin (sCT) in water were prepared by mixing. The amounts are given in Table 4. 450 mg of the compound was added to 2.0 mL of water. The sodium salt of the compound was used, or the free acid was converted to the sodium salt by mixing the resulting solution, adding one equivalent of sodium hydroxide (1.0N) and diluting with water. 90 µg of sCT was added to the solution. Water was then added to bring the final volume to 3.0 mL. The final solution concentration was 150 mg / ml. (For compounds 118 and 123, the solutions were diluted to 6.0 mL and the dose volume was doubled). The total sCT concentration was 30 µg / ml. (A different amount of sCT was used for compound 123, and when 2.0 ml / kg was administered, the final dose of sCT was 100 µg / kg).

Male Sprague-Dawley rats weighing 200-250 g were fasted for 24 hours and then dosed with ketamine (44 mg / kg) and chlorpromazine (1.5 mg / kg) 15 minutes prior to drug administration. Rats were administered the solution at 1 ml / kg (2 ml / kg for compounds 118 and 123). Blood samples were serially collected from the tail artery. Plasma sCT was determined using the EIA kit (Kit # EIAS-6003 from Peninsula Laboratories, Inc., San Carlos, CA). The standard kit application procedure was modified for compounds 104 and 105 as follows: incubate with 50 µl of peptide antibody for 2 hours with shaking in the dark, wash the plate, add plasma and biotinylated peptide, dilute with 4 ml of buffer and shake overnight in the dark. The results are shown in Table 3 below.

PL 212 652 B1

<td colspan="4">Table 3. Oral delivery of salmon calcitonin (sCT) to rats</td>

<td>Relationship</td><td>Compound dose (mg / kg)</td><td>SCT dose ^ g / kg)</td><td>Plasma sCT (pg / ml) ± SD (SE)</td>

<td> 105</td><td> 50</td><td> 25</td><td> 583 ±140</td>

<td> 105</td><td> 150</td><td> 30</td><td> 802 ± 669 (299)</td>

<td> 116</td><td> 150</td><td> 30</td><td> 724 ± 463 (207)</td>

<td> 117</td><td> 150</td><td> 30</td><td> 383 ± 292 (131)</td>

<td> 118</td><td> 150</td><td> 30</td><td> 276 ±319 (53)</td>

Patent claims