Pharmaceutical formulations comprising intranasal morphine and use thereof

The invention relates to nasal pharmaceutical compositions containing morphine or a pharmaceutically acceptable salt thereof at pH 3.0-7.0. The compositions of the present invention provide improved absorption useful in inducing analgesic or anesthetic reactions in mammals.

BACKGROUND OF THE INVENTION

Morphine or (-) 7,8-didehydro-4,5a-epoxy-17-methylmorphinan-3,6a-diol is a phenanthrene derivative having the following general structure:

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Morphine is a centrally acting narcotic analgesic that acts as an agonist of 30, primarily miu, kappa and. probably the delta receptor in the central nervous system. By acting on these receptors, morphine relieves pain and induces, via anesthesia, the central effect of receptors on the perception of pain, and the concomitant receptor-mediated modulating effect on the central deleterious sensation. Some of the side effects caused by morphine include drowsiness, respiratory depression and euphoria.

Various morphine salts are known in the pharmaceutical art. For example, morphine sulfate is one of the most commonly prescribed morphine formulations. Other morphine salts such as morphine tartrate and morphine lactate are described in U.S. Pat. No. 5,888d 132, issued to Hill, and U.S. Pat. No. 5,378,474 issued to Morella et al. for the treatment and prophylaxis of pain or tenderness. Several polar morphine compositions, including morphine-3-glucuronide and morphine-6-glucuronide, are described in Illum. 5,629,011.

Morphine is used for a variety of clinical indications. Some examples of such indications include pain relief by treating acute or chronic pain, analgesia during surgery, and relieving fear during acute pulmonary edema.

Several methods of administration are used to represent morphine. These techniques include oral, injectable, oral, and intranasal drug delivery. For example, oral or injectable morphine sulfate is usually given for cancer pain. Morphine sulfate for oral or injection is available from Roxane Pharmaceuticals Ine., US.

Several other ways of presentation were explored. For example, morphine intranasal formulation appeared promising for its rapid onset and onset of action. In addition, intranasal administration promises minimal absorption retention, is less invasive than intravenous delivery, and achieves therapeutically active plasma levels. For example, the intranasal presentation of morphine is described in Illum. U.S. Patent No. 5,629,011 to Hussain; 4,464,378. issued for the treatment of chronic and acute pain. Full U.S. Pat. No. 5,629,011 and U.S. Pat. 4,464,378 Descriptions Enable by mentioning them as links.

When examining intranasal drug presentations, their pharmacokinetics are frequently examined. For example, drug ionization is considered to have a direct effect on the membrane penetration of drugs and thus on the ability to be absorbed by the blood stream. Namely, the ionization of the drugs and the potential for their absorption is determined by the pH of the drug dissociation constant pK as well as the solution in which the drugs are dissolved. As described by Mayersohn in Modern Pharmaceutics, Banker &amp; Rhodes, 1979, d.2, p. 40, the parent compounds are best absorbed from alkaline solutions having a pH&gt; pK_{; i}. Thus, it is contemplated that compositions for the delivery of parent drugs, particularly intranasal compositions, are best absorbed by the blood stream when the parent drugs are formulated in a soluble composition having a pH greater than the drug dissociation constant. In this way, basic drugs such as morphine will be best absorbed in the base solution as it will be in a non-ionized state.

For example, morphine is known to be a basic drug with pK_a About 8. Morphine sulfate was considered to be an alkaline solution having a pH greater than 7.0 in order to ensure efficient membrane penetration and absorption by intranasal delivery.

Intranasal compositions of morphine sulfate at pH below 7.0 will contain more than 90% of the drug in its ionized form. Such drug ionization is likely to have poor intranasal absorption. Therefore, several morphine spray formulations are formulated with a pH between 7.0 and 8.0. For example, U.S. Pat. U.S. Patent No. 5,629,011 to Hussain; Morphine formulations for intranasal spray formulation with pPI 7.2 ± 0.2 were described in 4,464,378. These references contemplate the addition of different absorption enhancers for the purpose of achieving therapeutically effective levels of morphine by intranasal administration at such pH range.

Accordingly, efforts have focused on the addition of absorption enhancers for intranasal morphine formulations. A few examples of absorption enhancers include chitosan microspheres, cationic polymers, bioadhesive agents, surfactants, fatty acids, chelating agents, mucobial agents, and cyclodextrin.

Based on the foregoing, morphine compositions are required to provide enhanced absorption in the case of intranasal administration. Accordingly, the present invention provides an intranasal pharmaceutical composition containing morphine or a pharmaceutically acceptable salt thereof at a pH of 3.0 to 7.0. Such compositions provide therapeutically effective amounts of morphine to induce analgesic and anesthetic reactions.

The essence of the invention

The present invention provides an intranasal pharmaceutical composition containing morphine or a pharmaceutically acceptable salt thereof at a pH of 3.0 to 7.0.

In one embodiment, the present invention provides a method of inducing analgesic and anesthetic reactions in a mammal comprising administering a therapeutically active amount of morphine or a pharmaceutically acceptable salt thereof at a pH of from 3.0 to 7.0.

In another embodiment, the invention provides a method of inducing analgesic and anesthetic reactions in a mammal comprising administering a therapeutically effective amount of morphine or pharmaceutically acceptable salt thereof at a pH of from 3.0 to 7.0 to a mammal in association with a nasal delivery system.

Brief description of the drawings

FIG. 1 is a graph depicting plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 4.0 and contained a buffer of sodium citrate dihydrate and citric acid.

FIG. 2 is a graph depicting the plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 6.0 and contained sodium citrate dihydrate buffer.

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FIG. 3 is a graph depicting plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 6.0 pi and had a Tvveen 20 absorption enhancer.

FIG. 4 is a graph depicting plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 6.0 and had an absorption enhancer, sodium salicylate.

FIG. 5 is a graph depicting plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 6.0 and had an absorption enhancer polyoxyl 40 stearate.

FIG. 6 is a graph depicting the plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 3.5 and had absorption enhancers of Tveen 20 and glyceryl monooleate.

FIG. 7 is a graph depicting plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 6.0 and had absorption enhancers of Tvveen 20 and glyceryl monooleate.

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FIG. (8 is a graph depicting the plasma concentrations of free morphine when morphine sulfate was administered intranasally. Compositions pll was 6.0 and had Twecn 20 and lecithin absorption enhancers.

FIG. 9 is a graph depicting plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 6.0 and had absorption enhancers Tween 20 and sodium lauryl sulfate.

FIG. 10 is a graph depicting plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 6.0 and had absorption enhancers of Tween 20 and oleic acid.

FIG. 11 is a graph depicting plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 3.5 and had absorption enhancers Tween 20 and oleic acid.

FIG. 12 is a graph depicting plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 6.0 and contained absorption enhancers Tween 20, sodium salicylate and sodium lauryl sulfate.

FIG. 13 is a graph depicting plasma concentrations of free morphine when morphine sulfate was administered intranasally. The formulation had a pH of 6.0 and contained absorption enhancers Tween 20, sodium salicylate and oleic acid.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

The present invention is an intranasal pharmaceutical composition containing morphine or a pharmaceutically acceptable salt thereof at a pH of 3.0 to 7.0. In this description, the pharmaceutical composition comprises a pharmaceutically acceptable carrier which has

3f) an active agent, i.e. morphine or a pharmaceutically acceptable salt thereof. For purposes of this invention, a pharmaceutical carrier "includes nasal aerosols, nasal drops, gels, ointments, creams and the like.

Morphine is (-) - 7, tS-didehydro-4,5-c-coxy-17-melmormorphinan-3,6 &lt;z-diol. The term "5 chemically modified equivalents" includes compositions which may have a chemical structure that is different from morphine but functions similarly in the body, such as prodrugs, analogs, biologically active moieties, and the like.

Chemically modified equivalents of morphine include oxymorphone or (-) - 4,5a-cpoxy10 3,14-hydroxy-17-methylmorphinan-6-one, hydromorphone or (-) - 4,5a-epoxy-3-hydroxy-17-methylmorphinan-6- one, levorphanol (-) - 17-methylmorphinan-3-ol, nalbuphine or (-) - 17 (cyclobutylmethyl) - 4,5a-epoxymorphinan-3,5a, 14-triol. naloxone or (-) - 17-allyl-4,5aepoxy-3,14-dihydroxymorphinan-6-one, naltrexone or (-) - 17- (cyclopropylmethyl) 4,5a-epoxy-3,14-dihydroxymorphinan-6-one , nalmefcn or 6-deoxo-6-methylene-15 naltrexone, butorphanol, or (-) - 17 - (cyclobutylmethyl) -morphinan-3,14-diol. buprenorphine or (-) - 17- (cyclopropylmethyl) -α- (1,1-dimethylethyl) -4,5-epoxy-18,19-dihydro-3-hydroxy-6-methoxy-α-methyl-6,14-ethenomorphinan- 7-methanol. codeine, buprenorphine, nalorphine, hydrocodone, oxycodone. butorphanol, and pharmaceutically acceptable salts thereof.

The present invention includes pharmaceutically acceptable salts of morphine. Examples of pharmaceutically acceptable salts include salts consisting of an acid and a base which do not substantially increase the toxicity of the compound. A few examples of suitable salts include alkali metal salts such as magnesium, potassium and ammonium. Salts of mineral acids include salts of hydrochloric acid, hydroiodic acid, hydrobromic acid, phosphorus, metaphosphorus, nitric and sulfuric acids, and vinegar of organic acids such as tartaric acid. lemon, apple, benzine, amber, arylsulfonic, e.g. salts of p-toluenesulfonic acid and the like.

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Specific examples of suitable pharmaceutically acceptable salts of morphine include morphine sulfate, morphine-6-sulfal. morphine-3-sulfal, morphine-6-glucuronide, morphine-3-glucuronide, morphine tartrate, morphine lactate, morphine hydrochloride and combinations thereof.

Applicants have unexpectedly discovered that pharmaceutical compositions containing morphine or pharmaceutically acceptable salts thereof at pH 3.0 to 7.0 exhibit enhanced or significant absorption even when the drug is substantially ionized. In addition, nasal absorption has been found to be sensitive to pH in areas where the drug is ionized. Preferably, the pH of the morphine or pharmaceutically acceptable salt thereof is 4.0 to 7.0, more preferably 4.0 to 6.0, preferably 5.0 to 6.0.

Enhanced or marked absorption in this specification includes increases in plasma free morphine concentrations from 5% to 700%. Accordingly, a smaller amount of the drug may achieve the same therapeutic level that produces analgesic or anesthetic effects.

Morphine, chemical equivalents of morphine, and pharmaceutically acceptable salts of morphine may be obtained from various manufacturers. An example is morphine sulfate from Roxane Pharmaceuticals Ine., USA.

The amount of pharmaceutically acceptable morphine salt, such as morphine sulfate, which can be used to formulate the compositions of the invention may vary depending on the analgesic and anesthetic effects required in the mammal. Preferably, the amount of morphine salt used is from 0.01% to 50% by weight, more preferably from 1% to 10% by weight, preferably from 3% to 5% by weight, based on the total weight of the composition (w / w). In any event, the practice of the art will be guided by the present invention and the present invention includes without limitation the amounts of morphine used to achieve the effect described.

In an optimal embodiment, the morphine or pharmaceutically acceptable salt thereof is dissolved in a suitable solvent for intranasal administration, and the solvents selected include water, alcohol, glycerol, propyl glycol, and the like. Preferably, the amount of solvent is sufficient to dissolve the morphine or pharmaceutically acceptable salt thereof.

Preferably, the morphine is mixed at room temperature under a pressure of one atmosphere.

Intranasal administration

The present invention encompasses the nasal administration of a therapeutically effective amount of morphine or pharmaceutically acceptable salt thereof to a mammal. According to this use, nasal administration or intranasal administration involves the administration of morphine or a pharmaceutically acceptable salt thereof to the nasal passages or to the nasal cavity of a mammal.

In one embodiment, the present invention provides an effective amount of a pharmaceutical composition of morphine or a pharmaceutically acceptable salt thereof, together with a nasal delivery system.

According to the present invention, the pharmaceutical composition contains a therapeutically active morphine or

2 () is a pharmaceutically acceptable salt thereof. Such compositions may be administered, for example, as a nasal spray, nasal drops, suspension, gel, ointment, cream or powder. Administration of morphine compositions in the present invention may be accomplished using a nasal swab or nasal sponge containing morphine or a pharmaceutically acceptable salt thereof.

Nasal powder formulations may be formulated by mixing morphine or a pharmaceutically acceptable salt thereof with excipients, both having a fixed particle size. Other methods of making the desired powder formulations may be selected. First, a solution of morphine or a pharmaceutically acceptable salt thereof can be prepared which

5u is then precipitated, filtered and crushed. It is also possible to remove the solvent

K) freeze-drying followed by pulverization of the powder to the desired particle size using conventional techniques known in the pharmaceutical art. The powder may be administered using a nasal insufflator or other suitable means.

The powder may also be introduced in such a way that it is contained in a capsule.

The capsule is embedded in. gingival or insufflation device. The capsule is punctured with a needle, making holes in the bottom and top of the capsule, and the powder is blown out by air. The powder composition may also be delivered by a stream of inert gas or suspended in an organic liquid.

Morphine, or a pharmaceutically acceptable salt thereof, may also be present in a viscous base using conventional systems such as natural resins, methylcellulose and its derivatives, acrylic polymers (carbopol) and vinyl polymers (polyvinylpyrrolidones). The pharmaceutical compositions of the present invention may contain many other excipients known in the pharmaceutical art such as anticoagulants, surfactants, co-solvents, adhesives, antioxidants, buffers, viscosity and absorption enhancing agents and agents for regulating pH and osmotic properties.

Preferably, the morphine or pharmaceutically acceptable salt thereof is combined with a suitable system for delivery to the mammalian nasal mucosa. The nasal delivery system includes pharmaceutically acceptable buffer, thickener, moisturizer, absorption enhancers, and combinations thereof. Such nasal delivery systems may take a variety of forms including, for example, aqueous and nonaqueous solutions.

Aqueous solutions include, for example, aqueous gels, aqueous suspensions, aqueous liposomes, aqueous emulsions, aqueous microemulsions.

Non-aqueous solutions include, for example, non-aqueous gels, non-aqueous suspensions, non-aqueous liposomes, non-aqueous emulsions, and non-aqueous micro-emulsions.

The various forms of the nasal delivery systems indicated may include pi morphine or a pharmaceutically acceptable salt thereof, a buffering buffer, a pharmaceutically acceptable thickener, a humectant, absorption enhancers, and combinations thereof.

As stated above, morphine or pharmaceutically acceptable salt-containing compositions thereof were unexpectedly found to exhibit significant absorption through the nasal mucosa at pH 3.0-7.0 even when the morphine is in an ionized state. The pH choices of the nasal formulation are determined by an appropriate balance between drug absorption size, drug stability, drug solubility. Preferably, the morphine or pharmaceutically acceptable salt thereof in combination with the nasalinc delivery system has a pH of 4.0-7.0, more preferably 4.0-6.0, preferably 5.0-6.0.

It will be apparent to those skilled in the art that to maintain the pH of the composition below 7.0, the nasal delivery system must have a buffer of the required buffer capacity. Of course, the particular buffer may be selected depending on the particular nasal delivery system as well as the specificity of the morphine formulation selected. Suitable buffers for use in the present invention are, for example, acetate, citrate, prolamine, carbonate and phosphate buffers and combinations thereof. Particularly suitable buffers are sodium citrate dihydrate and citric acid.

Suitable forms of buffering agents for non-aqueous and powder formulations may be selected such that, when the composition is administered to the mammalian nasal cavity, the selected pH values ​​are achieved by contact, for example, with the nasal mucosa.

As above, the pH of the pharmaceutical composition should be 3.0-7.0. Therefore, pharmaceutical compositions of the present invention may contain pH-adjusting agents, examples of pi-regulating agents include prolamines, sulfuric acid, sodium hydroxide, dilute hydrochloric acid and the like. Preferably, the pH adjusting agent is added to the compositions as required to maintain a pi of 4.0-6.0. and preferably 5.0-6.0.

The viscosity of the composition of the present invention may be maintained at the desired level using pharmaceutically acceptable thickeners. Such agents may also be used in specific compositions of the present invention. The concentration of the thickener will depend on the agent selected and the viscosity desired. The best thickener is polyvinyl alcohol. The concentration of such an agent may be present in the composition in an amount of 0.1% to 20% by weight, based on the total weight of the composition.

The compositions of the present invention may also have a tolerance enhancer to reduce or stop the drying of the mucous membrane and prevent irritation. A suitable tolerance enhancer that may be used in the present invention includes moisturizers.

for example, sorbitol, mineral oil, vegetable oil, glycerol, glycerol, emollients, membrane conditioners, sweeteners and combinations thereof. The concentration of the tolerance enhancer (s) in these compositions will vary with the agent selected. The concentration of the tolerance enhancer in the delivery system may be from 0.01% to 20% by weight of the total composition.

Because of the enhancement of morphine or pharmaceutically acceptable salt thereof through the nasal mucosa, the nasal delivery system contains a therapeutically acceptable enhancer. Suitable absorption enhancers that may be used in the present invention include, for example, sodium lauryl sulfate, sodium salicylate.

oleic acid, lecithin, dehydrated alcohol, Tvveen, Span, polyoxyl 40 stearate. polyoxyethylene 50 stearate, disodium edetate, propylene glycol, glycerol monooleate, fusates, bile salts, octoxynol, and combinations thereof. According to this description, Tvveen includes all Tvveen. such as Tvveen 20, Tvveen 40. 'Ivveen 00. Tvveen 80 and the like. Span include all Span. such as Span 20. Span 40. Span 80 and so on. Suitable absorption enhancers include nonionic, anionic and cationic surfactants. Improved absorption of these! the concentration in the delivery system may range from 0.01% to 50% by weight of the total composition.

For example, optimal concentrations of sodium salicylate, sodium lauryl sulfate, disodium edetate may be from 0.01% to 5% by weight of the total composition. Polyoxyl 40 stearate. Suitable concentrations of lccitin, dehydrated alcohol, may be from 0.1% to 10% by weight of the total composition. The concentration of oleic acid lt) may preferably be from 0.01% to 5% by weight of the total composition. Propylene glycol and Tween 20 may be present in concentrations of from 0.1% to 25% by weight of the total composition.

Absorption enhancers of the present invention increase plasma levels of free morphine compared to those observed without absorption enhancer. Plasma concentrations of optimally free morphine are increased from 5% to 700%. Accordingly, a smaller amount of medication may be used to achieve the same therapeutic level of analgesic or anesthetic response.

Other non-essential ingredients of the present invention may also be included in the nasal delivery system provided that they do not interfere with or significantly reduce the absorption of morphine or pharmaceutically acceptable salt through the nasal mucosa. Such ingredients may include, for example, pharmaceutically acceptable excipients and anticoagulants. These excipients which may be used according to the invention are, for example, bioadhesives and / or swellers / thickeners and combinations thereof.

Anticoagulants may be added to these compositions to extend the shelf-life. Suitable anticoagulants for these compositions can be used, for example, benzyl alcohol, parabels, thimerasol, chlorobutanol. bcnzalkonium and combinations thereof, the best being benzalkonium chloride. Most often, the anticoagulants in the compositions will be from 0.001% to 5% by weight of the total composition. However, the exact concentration of the anticoagulant will vary with the intended use and can be readily determined by one of ordinary skill in the art.

Other ingredients may be added. which extend the shelf life, such as antioxidants. Examples of antioxidants include mctabisulfite sodium, potassium mctabisulfite, ascorbic palmitate, and the like. Typically, the antioxidant in the compositions will be from 0.01% to 5% by weight of the total composition.

It has been unexpectedly discovered that morphine or pharmaceutically acceptable salts thereof achieve enhanced or marked absorption at pH 3.0-7.0 and can be used to induce analgesic or anesthetic effects as observed with morphine at higher pH values. In addition, nasal absorption has been found to be pH sensitive in the pH range where drugs are most ionized.

Therapeutically effective amount

In this specification, an effective amount of morphine or pharmaceutically acceptable salt thereof is such that it causes an analgesic or anesthetic reaction. For example, morphine or pharmaceutically acceptable salts thereof may act to alleviate or alleviate a state of dread and palliative pain and chronic or acute pain. Preferably, morphine or pharmaceutically acceptable salt thereof is administered in an amount that most restricts the overall side effects, such as respiratory depression, constipation, and lethargy.

The minimum dose of morphine or pharmaceutically acceptable salt thereof is the lowest dose. which causes analgesia and anesthesia in the mammal. For example, morphine or pharmaceutically acceptable salt thereof may be administered in a minimal dose of at least 0.01 mg / kg to 4 mg / kg body weight, preferably at least 1 mg / kg to 4 mg / kg body weight, and preferably at least 2 mg / kg to 4 mg / kg body weight.

The maximum dose in mammals is the highest dose. which causes analgesia or anesthesia but does not cause undesirable or intolerable side effects such as respiratory depression. In any case, the practice is based on the experience in the art and the present invention includes, without limitation, dosages that are effective in mammals to achieve the effect described.

According to this description, analgesia or analgesic reaction involves the suppression of pain in a mammal without causing loss of consciousness. Most often, morphine or a pharmaceutically acceptable salt thereof can be used to induce analgesia in the relief of acute and chronic pain. Morphine or a pharmaceutically acceptable salt thereof may also be used to induce anesthesia or anesthetic reaction in a mammal. Mostly.

loss of sensory and sensory sensitivity in mammals is practically applied, especially loss of sensitivity to pain to allow for surgical and other painful procedures. Accordingly, when analgesia is induced, the mammal loses consciousness.

Mammals include, for example, humans as well as animals such as dogs and cats, laboratory animals such as rats and mice, and domestic animals such as horses and cows.

The following examples are provided to illustrate the compositions of the present invention as well as the extraordinary results thereof. These examples are provided for illustrative purposes only and are not limiting in any way.

EXAMPLE

Morphine sulfate compositions having a pH of 4.U-6.U

FIG. 1 is a graph showing plasma concentrations of free morphine at 10 mg

3n morphine sulfate was administered intranasally to healthy volunteers. using lf)

Composition I (Table I). This formulation had a pll of 4.0 and contained buffers of sodium citrate dihydrate and citric acid. FIG. 2 is a graph showing plasma concentrations of free morphine when 10 mg of morphine sulfate was administered intranasally to healthy volunteers using formulation 2 (Table 2). The pi I of this formulation was 6.0 and contained a sodium citrate dihydrate buffer. Mean peak concentrations (Cmax) for intranasal. 1 and formulation 2 had concentrations of 6.58 ng / ml and 10.3 ng / ml, respectively. Compositions 1 and 2 had no absorption enhancer. It was observed that the average Cm of 2 compositions_Awas about 60% higher when the pH was raised to 6.0 compared to the same dose of 10 mg morphine sulfate at pH 4.0 (1 to formulation). It was also found that the solubility of morphine sulfate at pH 4.0-6.0 is pH independent. These results were unexpected since morphine sulfate is predominantly in its ionized state in the pH range 4.0-6.0 and therefore absorption is expected to be weak and not pH dependent. In contrast, significant absorption was found in the pH range 4.0-6.0, where the drugs are predominantly ionized. Accordingly, nasal absorption is sensitive to changes in pH in this area.

EXAMPLE

Morphine Sulfate Composition with Absorption Enhancer Tvveen 20

FIG. 3 is a graph showing plasma concentrations of free morphine when 9 mg of morphine sulfate was administered intranasally to healthy volunteers using the composition. This formulation had a pH of 6 and contained about 5 wt% of the absorption enhancer Tveen 20 (polysorbate 20) (Table 3). Mean peak concentrations (Cmax) for intranasal formulation 3 were 17.8 ng / ml. It was observed that Tvveen 20 at pH 6.0 increased the nasal absorption of morphine sulfate by more than 73% compared to that obtained with citrate buffer and without an enhancer at pH 6.0 as in formulation 2 (Table 2). These results were unexpected as morphine sulfate is. predominantly in its ionized state in the piI range of 4.0 to 6.0 and therefore poor absorption is likely. In contrast, significant absorption was found in the pH range 4.0-6.0. where the medications are. predominantly, ionized. Also the addition of an absorption enhancer.

bear like Twccn 20, increased intranasal absorption and maximum plasma concentrations of morphine, although lower doses of morphine sulfate were used.

EXAMPLE

Morphine Sulfate Composition with Sodium Salicylate Absorption Improved!

FIG. 4 is a graph showing plasma concentrations of free morphine when 10 mg of morphine sulfate was administered intranasally to healthy volunteers using the composition. This formulation had a pH of 6.0 and had an absorption enhancer! 1% sodium salicylate (Table 4). Mean peak concentrations (Cmax) for intranasal administration of that composition were 13.3 ng / ml. It was observed that sodium salicylate at pH 6.0 increased the nasal absorption of morphine sulfate by about 30% compared with that obtained with citrate buffer and without the pH 6.0 enhancer as in formulation 2 (Table 2). These results were unexpected because morphine sulfate is predominantly in its ionized state at pH 4.0-6.0 and was therefore expected to be poorly absorbed and not pH dependent. In contrast, significant absorption was found in the pH range 4.0-6.0. where drugs are, predominantly, ionized. Addition of an absorption enhancer such as sodium salicylate also increased the intranasal absorption and the peak of morphine plasma concentrations.

EXAMPLE

Morphine sulfate compositions with polyoxyl 40 stearate absorption enhancers

FIG. 5 is a graph showing plasma concentrations of free morphine when 7.4 mg of morphine sulfate was administered intranasally to healthy volunteers using the composition. This formulation had a pH of 6.0 and contained about 10% absorption-enhanced polyoxyl 40 stearate (Table 5). Mean peak concentrations (C \ ia \) for intranasal formulation were 14.1 ng / ml. It was observed that the use of polyoxyl 40 stearate at pH 6.0 increased the nasal absorption of morphine sulfate by about 37% compared to that observed with citrate buffer and without the enhancer at pH 6.0 as in formulation 2 (Table 2). In addition, using polyoxyl 40 stearate. absorption was less than 3 compositions at pH 6.0 at 5% Tveen 20 concentration.

31) These results were unexpected because morphine sulfate is predominantly in its ionized form

1S in the pH range of 4.0 to 6.0 and therefore, absorption was expected to be poor. In contrast, significant absorption was found in the pH range 4.0-6.0, where the drugs are predominantly ionized. The addition of absorption enhancers such as polyoxyl 40 stearate and Tveen 20 also increased intranasal absorption and peak plasma morphine concentrations, although lower doses of morphine sulfate were used.

EXAMPLE

Morphine Sulphate Powder Formulations with Tvveen 20 and Glyceryl Monoolcate

K) FIG. 6 is a graph showing plasma concentrations of free morphine when 10 mg of morphine sulfate was administered intranasally to healthy volunteers using the composition (Table 6). This formulation had a pH of 3.5 and had absorption enhancers of 5% Tween 20 and 5% glyceryl monoolcate. FIG. 7 is a graph showing plasma concentrations of free morphine when 10 mg of morphine sulfate was administered intranasally using composition 7. This formulation had a pH of 6.0 and had absorption enhancers of 5% Tween 20 and 5% glyceryl monooleate. Mean peak concentrations (Cmax) for intranasal formulations 6 and 7 were 19.0 ng / ml and 11.6 ng / ml, respectively. For composition 6, the use of each of the absorption enhancers 5% Tvveen 20 and 5% glyceryl monooleate provided comparable nasal absorption of morphine sulfate at pH 3.5 compared to 5% Tvveen 20 at pH 6.0 (formulation 3). These results were unexpected, since the formulation at pH 3.5 should exhibit much lower morphine absorption. In addition, for composition 7, use of 5% glyceryl monooleate and 5% Tvveen 20. each resulted in increased nasal absorption of morphine sulfate at pH 6.0 compared to that obtained with citrate buffer and no enhancer at pH 6.0 as in formulation 2. (Table 2). In addition, the absorbance of formulation 7 was not increased compared to that found in formulation 3, which had 5% Tveen 20 at pH 6.0.

EXAMPLE

Morphine Sulphate Compositions with Tvvccn 20, Lecithin and / or Sodium Lauryl Sulphate Absorption Enhancers

FIG. Figure 8 is a graph showing plasma concentrations of free morphine when 8.9 mg of morphine sulfate was administered to healthy volunteers by inhalation using the composition (Table 8). This formulation had a pl of 6.0 and had 5% Tvccn 20 and about 1% lecithin absorption enhancers. FIG. 9 is a graph showing plasma concentrations of free morphine when 9.4 mg of morphine sulfate was administered intranasally to healthy volunteers using composition 9 (Table 9). This formulation had a pH of 6.0 and contained 5% Tween 20 and about 1% sodium lauryl sulfate absorption enhancers. Mean peak concentrations (Cmax) for intranasal 8 and formulations were 13.1 ng / ml and 52.2 ng / ml, respectively. As for Figs. The use of 8, 1% lecithin and 5% Tvveen 20 enhanced the nasal absorption of morphine sulfate at pH 6.0 (in formulation 8) compared with that found using citrate buffer at pH 6.0 in formulation 2 (Table 2). 8th the composition did not increase the absorbance compared to that found in composition 3, which had 5% Tveen 20 at pH 6.0. As for Figs. The use of 9, 1% lauryl sulfate and 5% Tvveen 20 at pH 6.0 (formulation 9) enhanced the nasal absorption of morphine sulfate at pH 6.0 compared with that found with formulation 3, which had 5% Tvveen 20 also at pH 6, 0. The increase in absorbance was 300% relative to the mean peak concentrations of compositions 3 and 9. These results were unexpected because morphine sulfate is predominantly in its ionized state at pH 4.0-6.0 and was therefore expected to have poor absorption. In contrast, significant absorption was found in the pH range 4.0-6.0, where the drugs are predominantly ionized.

EXAMPLE

Morphine sulfate formulations with oleic acid and Tween 20 absorption enhancers

FIG. 10 is a graph showing plasma concentrations of free morphine when 9.5 mg of morphine sulfate was administered intranasally to healthy volunteers using composition (Table K). This formulation had a pi I of 6.0 and contained about 0.259 µg of oleic acid and about 5% Tveen 20 absorption enhancers. FIG. 11th is a graph showing plasma concentrations of free morphine when 9.0 mg of morphine sulfate was administered intranasally to healthy volunteers using formulation 11 (Table 11). This formulation had a pH of 3.5 and contained about 0.25% oleic acid and 5% Tvveen 20 absorption enhancers. Mean peak concentrations (C \,_Ax) Intranasal formulations 10 and 11 contained 31.9 ng / ml and 27.5 ng / ml, respectively.

As for Figs. The use of 10, 0.25% oleic acid and 5% Tvveen 20 enhanced the nasal absorption of morphine sulfate at pH 6.0 as compared to formulation 3, which had 5% Tvveen 20 also at pH 6.0. As for Figs. The use of 11, 0.25% oleic acid and 5% Tvveen 20 at pH 3.5 enhanced the nasal absorption of morphine sulfate as compared to formulation 3, which had 5% Tvveen 20 at pH 6.0. These results were unexpected due to the presence of morphine sulfate. predominantly in its ionized state at pH 3.5-6.0 and therefore expected to have poor absorption. In contrast, significant absorption was found in the pH range 3.5-6.0, where the drugs are predominantly ionized.

8th EXAMPLE

Compositions of morphine sulfate with sodium lauryl sulfate, Tween 20 and oleic acid or sodium salicylate absorption enhancers

FIG. 12 is a graph showing plasma concentrations of free morphine when 8.5 mg of morphine sulfate was administered intranasally to healthy volunteers using composition 12 (Table 12). This composition had a pH of 6.0 and had about 5% Tveen 20. about 0.5% sodium salicylate and 0.5% sodium lauryl sulfate absorption enhancers. FIG. 13 is a graph showing plasma concentrations of free morphine when 9.4 mg of morphine sulfate was administered intranasally to healthy volunteers,

3o using composition 13 (Table 13). This formulation had a pll of 6.0 and had about 5% Twecn 20, about 1% sodium lauryl sulfate, and about 0.5% oleic acid absorption enhancers. Mean peak concentrations (C'max) for intranasal formulations 12 and 13 were 25.6 ng / ml and 51.7 ng / ml, respectively. As for Figs. 12th The use of 0.5% sodium lauryl sulfate, 0.5% sodium salicylate, and 5% Tvvccn 20 enhanced the nasal absorption of morphine sulfate at pi I 6.0 compared to 5% Tvvecn 20 also at pH 6.0. As for Figs. The use of 13, 1% sodium lauryl sulfate, 0.5% oleic acid and 5% Tvvcen 20 enhanced the nasal absorption of morphine sulfate at pH 6.0 compared to 5% Tween 20 also at pH 6.0 (formulation 3).

In summary, the above results were unexpected as morphine sulfate is predominantly in its ionized state in the pH range of 3.5-6.0 and was expected to have poor absorption. In contrast, significant absorption was found in the pH range 3.5-6.0, where the drugs are predominantly ionized. Also, the addition of absorption enhancers such as Tvveen 20, sodium laurilsulfate, sodium salicylate and oleic acid increased intranasal absorption and peak plasma concentrations of morphine.

It will be apparent from the description of the present invention that there may be many embodiments thereof. These variations should not be construed as a departure from the spirit and scope of the invention and any such modifications must be included within the scope of the invention.