PHARMACEUTICAL COMPOSITIONS COMPRISING 5-HT1 RECEPTOR AGONISTS AND ABSORPTION ENHANCERS

Abstract: The invention relates to a liquid pharmaceutical composition for oral administration which comprises a compound which acts as a 5HT1-like receptor agonist or a physiologically acceptable salt or solvate thereof, as active ingredient, and an absorption enhancing carrier. Methods for the manufacture of such compositions and for their use in the treatment of cephalic pain are also described.

Description: PHARMACEUTICAL COMPOSITIONS COMPRISING 5-HT, RECEPTOR AGONISTS AND ABSORPTION ENHANCERS The present invention relates to a pharmaceutical composition containing as active ingredient a compound having selective agonist activity at 5HT- | -like receptors, in particular a composition for oral administration. 5-l-πyiike receptors are located, for example, in the dog saphenous vein and the 5-HT-j-like receptor agonists with which the present invention is concerned contract the dog saphenous vein. Such compounds may therefore be identified by their contractile effect on the dog isolated saphenous vein strip as described, for example, by Apperley et al., Br. J. Pharmacol, 68, 215-224 (1980). Compounds which are selective 5-HT^Iike receptor agonists have also been found to selectively constrict the carotid arterial bed of the anaesthetised dog. A variety of compounds which selectively constrict the dog isolated saphenous vein strip and which constrict the carotid arterial bed of the anaesthetised dog have been described in the art. These include indole derivatives such as those disclosed inter alia in published British Patent Specifications Nos. 2082175, 2081717, 2083463, 2124210, 2150932, 2162522, 2168347, 2168973, 2185020, 2186874, 2191488, 2208646, published European Patent Specifications Nos. 147107, 237678, 242939, 244085, 225726, 254433, 303506, 313397, 354777, 382570, 464558, 506363, 506369, 450238, 451022, 451008, 478954, 438230, 494774, 497512, 501568 and published International patent application Nos. WO92/11013, W092/11014, WO92/06973, WO93/00086, W092/13856, WO93/00094, W091/18897 and WO93/00333. The compounds disclosed in the specifications (hereinafter described as compounds A) are useful in the treatment of migraine and cluster headache. The present invention provides a liquid pharmaceutical composition for oral administration which comprises a compound which acts as a 5HT r like receptor agonist or a physiologically acceptable salt or solvate thereof, as active ingredient, and an absorption enhancing carrier. Oral administration constitutes the generally preferred route for administration of pharmaceuticals since this route is particularly convenient and acceptable to patients. It is highly desirable, particularly in the treatment of acute conditions such as migraine, that pharmaceutical compositions have a rapid and consistent onset of action combined with sustained activity and good bioavai lability. Rapid absorption can be achieved by parenteral injection but this is unacceptable to some patients, particularly if the drug is to be administered without direct medical supervision, i.e. self-administered. We have now found that the compositions according to the invention have excellent stability, formulation and pharmacokinetic characteristics. In a preferred embodiment of the invention we provide a liquid pharmaceutical composition for oral administration which comprises one or more of compounds A or a pharmaceutically acceptable salt or solvate thereof, as active ingredient, and an absorption enhancing carrier. Compositions according to the invention are preferably in a form adapted for use in medicine, in particular human medicine. Particularly preferred compounds for use in the compositions of the present invention are 3-[2-(dimethylamino)ethyl]-N-methyl-1 H-indole-5- methanesulphonamide and N-methyl-3-(1-methyl-4-piperidinyl)-1 H-indole-5- ethanesulphonamide, especially 3-[2-(dimethylamino)ethyl]-N-methyl-1 H-indole- 5-methanesulphonamide. 3-[2-(Dimethylamino)ethyl]-N-methyl-1 H-indole-5-methanesulphonamide, which may be represented by the formula (I) I H and its physiologically acceptable salts and solvates are disclosed in GB 2162522. The compound of formula (I) is described as useful in treating and/or preventing pain resulting from dilatation of the cranial vasculature, in particular migraine. Numerous clinical studies have demonstrated the effectiveness of the compound of formula (I) (generic name sumatriptan) in migraineurs, either by oral or intranasal administration or by parenteral injection. Nevertheless, alternative oral formulations of sumatriptan with an enhanced onset of action are highly desirable. The applicants have demonstrated that certain liquid formulations of sumatriptan provide faster absorption than solid dosage forms (i.e. tablets) of sumatriptan. The invention thus provides in a particularly preferred aspect a liquid formulation comprising 3-[2-(dimethylamino)ethyl]-N-methyl-1 H-indole-5- methane-sulphonamide or a pharmaceutically acceptable salt or solvate thereof and an absorption enhancing carrier. The liquid formulations according to the invention may be in the form of a solution, an emulsion or a suspension. Pharmaceutically acceptable salts of compounds A include those derived from pharmaceutically acceptable inorganic and organic acids. Examples of suitable acids include hydrochloric, hydrobromic, sulphuric, nitric, perchloric, fumaric, rnaleic, phosphoric, glycolic, lactic, salicylic, succinic, toluene-p-sulphonic, tartaric, acetic, citric, methanesulphonic, formic, benzoic, malonic, naphthalene- 2-sulphonic and benzenesulphonic acids. A preferred salt is a succinate salt, more particularly the (1 :1 ) succinate salt. However, the applicants have found that formulations of the present invention are surprisingly advantageous when the active compound is in the form of its free base. Absoφtion enhancing carriers may comprise water immiscible liquids, solids or semi-solids such as vegetable oils, aromatic oils, aliphatic and aromatic hydrocarbons, fatty acids and their triglycerides and esters, chlorinated hydrocarbons, ethers and esters or water-miscible non-volatile liquids, solids or semi-solids such as propylene glycol and other polyethylene glycols (e.g. PEG300, 400 or 600) and nonionic or amphoteric surfactants such as lecithin. Preferably the absorption enhancing carrier will comprise one or more unsaturated fatty acids such as oleic acid and linoleic acid, either alone or advantageously in combination with one or more further absorption enhancing carriers such as polyethylene glycol and propylene glycol. Oleic acid is a particularly preferred absoφtion enhancing carrier. Preferably surface active agents, such as polysorbate, bile salts and lecithin will also be present in the formulation. A particularly preferred surface active agent is polysoΦate 80. The active compound will normally be present in the liquid formulation in an amount of about 5 to about 30% w/w, in particular from about 10 to 25% w/w, preferably from 14-17% w/w. The absorption enhancing carrier may either provide the balance of the formulation when present as the only excipient (i.e. from 95-70% w/w of the formulation) or where other excipients are present from 40-80% w/w of the formulation, for example 50-80% in particular from 60-75% of the formulation. Surface active agents may be present in an amount of from about 0.01 to about 20% w/w, in particular from about 1 to about 20%, for example about 10% w/w. A preferred formulation according to the invention comprises a compound which acts as a 5HT like receptor agonist in the form of its free base and oleic acid as absorption enhancing carrier, optionally together with a polyethylene glycol. A particularly preferred formulation further comprises polysorbate as surface active agent. The formulations of the invention may be employed directly in liquid form for oral administration. Conveniently, however, the formulation is presented in unit dosage form in gelatin capsules, in particular soft gelatin capsules, although hard gelatin capsules may also be employed. Thus the invention provides in a further aspect a pharmaceutical formulation in the form of a capsule and comprising a liquid fill of a compound which acts as a 5HT like receptor agonist or a pharmaceutically acceptable salt or solvate thereof and an absoφtion enhancing carrier, surrounded by a gelatin shell. When the formulation is presented in the form of a capsule, the active compound will be present in an amount ' of from about 1 to about 200mg, preferably about 10 to about 200mg, for example about 25 to about 100mg of active compound calculated as the free base. The pharmaceutical formulations of the invention may also contain other active ingredients, in particular other antimigraine agents, antinauseants or « analgesics. The formulations may be prepared in conventional manner, for example by intimate admixture of the active ingredient with the carrier. Preferably the formulations are manufactured with minimum exposure to air, for example processed under nitrogen. However, the formulations may contain antioxidants such as butylated hydroxyanisole, butylated hydroxytoluene, lactic acid and ascorbyl palmitate or preservatives in order to minimise oxidation and microbial contamination. Antioxidants may be present in an amount of from about 0.005 to 0.1% w/w, preferably 0.01 to 0.05% w/w. Other excipients conventionally used in the art of pharmaceutical formulation may also be present. A further aspect of the invention provides a method for the treatment of a mammal, including man, suffering from or susceptible to conditions associated with cephalic pain such as cluster headache, chronic paroxysmal hemicrania, headache associated with vascular disorders, headache associated with substances or their withdrawal (for example drug withdrawal), tension headache and in particular migraine which comprises oral administration of a liquid pharmaceutical composition which comprises a compound which acts as a 5HTι-like receptor agonist or a pharmaceutically acceptable salt or solvate thereof as active ingredient, together with a pharmaceutically acceptable absorption enhancing carrier. It will be appreciated that reference to treatment is intended to include prophylaxis as well as the alleviation of established symptoms. It will be appreciated that the amount of , compounds which act as 5HT like receptor agonists employed in the compositions of the invention will depend on the particular compounds used. Furthermore, the precise therapeutic dose of the active ingredient will depend on the age and condition of the patient and the nature of the condition to be treated and will be at the ultimate discretion of the attendant physician. However, in general, effective doses for the treatment of conditions associated with cephalic pain, for example acute treatment of migraine, will lie in the range of 1 to 500mg, preferably 2 to 200mg, most preferably 5 to 100mg, for example 10mg or 25mg of the active ingredient per unit dose which could be administered in single or divided doses, for example, 1 to 4 times per day. The following examples are illustrative of the invention but are not intended as a limitation thereof. Exam le 1 - 7 Liquid formulations were prepared by slow addition of the active ingredient (A) into the other ingredients (B-D) at 35-50°C with constant mixing (amounts are given as percentage w/w). Example? § and 9 Liquid formulations were prepared by slow addition of active ingredient (A) into the other ingredients (B-D) at 35-50 * C with constant mixing (amounts are given as percentage w/w). Examples 10 - 13 The liquid formulations of Examples 1 , 3, 4 and 5 were filled into hard gelatin capsules, each capsule containing 25mg of sumatriptan. Examples 14 - 22 The liquid formulations of Examples 1 to 9 were filled into hard gelatin capsules, each capsule containing 100mg of sumatriptan. Examples 23 - 31 Liquid formulations are prepared as described in Examples 1 to 9 wherein the active ingredient A1 was N-methyl-3-(1-methyl-4-piperidinyl)-1 H-indole-5- ethanesulphonamide and active ingredient A2 was N-methyl-3-(1-methyl-4- piperidinyl)-1 H-indole-5-ethanesulphonamide hydrochloride. Examples 32 - 40 The liquid formulations of Examples 23 to 31 are filled into hard gelatin capsules, each capsule containing 10mg of N-methyl-3-(1-methyl-4-piperidinyl)- 1 H-indole-5-ethanesulphonamide.

Claims: Claims 1. A liquid pharmaceutical composition for oral administration which comprises a compound which acts as a 5HT r like receptor agonist or a physiologically acceptable salt or solvate thereof, as active ingredient, and an absorption enhancing carrier. 2. A pharmaceutical composition as claimed in claim 1 wherein the active ingredient is selected from 3-[2-(dimethylamino)ethyl]-N-methyl-1 H-indole-5- methanesulphonamide, N-methyl-3-(1 -methyl-4-piperidinyl)-1 H-indole-5- ethanesulphonamide and pharmaceutically acceptable salts and solvates thereof. 3. A pharmaceutical composition as claimed in claim 1 wherein the active ingredient is 3-[2-(dimethylamino)ethyl]-N-methyl-1 H-indole-5- methanesulphonamide or a pharmaceutically acceptable salt or solvate thereof. 4. A pharmaceutical composition as claimed in any one of claims 1 to 3 wherein the active ingredient is in the form of its free base. 5. A pharmaceutical composition as claimed in any one of claims 1 to 4 wherein the absorption enhancing carrier comprises one or more unsaturated fatty acids. 6. A pharmaceutical composition as claimed in claim 5 wherein the absorption enhancing carrier comprises oleic acid. 7. A pharmaceutical composition as claimed in any one of claims 1 to 6 which further comprises a polyethylene glycol. 8. A pharmaceutical composition as claimed in any one of claims 1 to 7 which further comprises propylene glycol. 9. A pharmaceutical composition as claimed in any one of claims 1 to 8 which further comprises a surface active agent. 10. A pharmaceutical composition as claimed in claim 9 wherein the surface active agent is selected from polysorbate, bile salts and lecithin. 11. A pharmaceutical composition as claimed in claim 10 wherein the surface active agent is polysorbate 80. 12. A pharmaceutical composition as claimed in any one of claims 9 to 11 wherein the surface active agent comprises about 0.01 to about 20% w/w of the composition. 13. A pharmaceutical composition as claimed in any one of claims 1 to 12 wherein the active ingredient comprises about 5 to about 30% w/w of the composition. 14. A liquid pharmaceutical composiiton for oral administration which comprises a compound which acts as a 5HT-,-like receptor agonist in the form of its free base and oleic acid as absorption enhancing carrier, optionally together with a polyethylene glycol. 15. A pharmaceutical composition as claimed in claim 14 which further comprises polysorbate. 16. A pharmaceutical composition as claimed in any one of claims 1 to 15 in unit dosage form. 17. A pharmaceutical composition as claimed in claim 16 in the form of a gelatin capsule comprising a liquid fill of a compound which acts as a 5HT r like receptor agonist or a pharmaceutically acceptable salt or solvate thereof and an absorption enhancing carrier, surrounded by a gelatin shell. 18. A pharmaceutical composition as claimed in claim 16 or claim 17 which comprises about 1 to about 200mg of active ingredient. 19. A method for the manufacture of a pharmaceutical composition as claimed in any one of claims 1 to 18 which comprises intimate admixture of the active ingredient with the carrier. 20. A method for the treatment of a mammal, including man, suffering from or susceptible to conditions associated with cephalic pain such as cluster headache, chronic paroxysmal hemicrania, headache associated with vascular disorders, headache associated with substances or their withdrawal (for example drug withdrawal), tension headache and in particular migraine which comprises oral administration of a liquid pharmaceutical composition comprising a compound which acts as a 5HT-,- like receptor agonist or a pharmaceutically acceptable salt or solvate thereof, as active ingredient, and an absorption enhancing carrier. 21. A method as claimed in claim 20 wherein the 5HT like receptor agonist is 3-[2-(dimethylamino)ethyl]-N-methyl-1 H-indole-5-methanesulphonamide or a pharmaceutically acceptable salt or solvate thereof. 22. A method as claimed in claim 20 or claim 21 wherein the active ingredient is in the form of its free base.

Inventors: DOHERTY CHRISTOPHER, GAMBHIR RENU, DOHERTY, CHRISTOPHER, GAMBHIR, RENU
Applicants: DOHERTY CHRISTOPHER, GAMBHIR RENU, GLAXO CANADA, GLAXO CANADA INC.
Application year: 1993
Main classification: A61K31
IPC codes: A61K9, A61K31, A61K45, A61K47, A61P25