Claims for Patent: 5,914,334

Summary for Patent: 5,914,334

Title:	Stable gel formulation for topical treatment of skin conditions
Abstract:	The present invention provides a stable gel formulation for topical treatment of skin conditions in humans. The stable gel formulation includes an active agent, having activity for treatment of acne and psoriasis, which is insoluble in water and a plurality of nonaqueous vehicles for both solubilizing said active agent and forming a gel therewith enabling topical application of the gel to a skin condition. The plurality of vehicles are each present in amounts, and in combination, to control release of the active agent from the gel to the skin condition.
Inventor(s):	Charu; Prakash M. (Fullerton, CA)
Assignee:	Allergan, Inc. (Irvine, CA)
Application Number:	08/623,184
Patent Claims:	1. A stable gel formulation for topical treatment of both acne and psoriasis comprising an effective amount of a compound having the formula Ethyl-6-[2-(4,4-dimethylthiochroman-6-yl)-ethynyl]nicotinate in a pharmaceutical carrier comprising: (a) water; (b) edetate disodium; (c) ascorbic acid; (d) Carbomer 934P; (e) Poloxamer 407; (f) polyethylene glycol; (g) Polysorbate 40; (h) hexylene glycol; (i) butylated hydroxytoluene; (j) butylated hydroxyanisole; (k) benzyl alcohol: and (l) tromethamine wherein the Polysorbate 40 is present in an amount up to about 0.4% by weight, Poloxamer 407 is present in an amount up to about 0.4% by weight, and hexylene glycol is present in an amount up to about 2% by weight. 2. The formulation according to claim 1, wherein the Polysorbate 40 is present in an amount of about 0.32% by weight, the Poloxamer 407 is present in an amount of about 0.18% by weight, and the hexylene glycol is present in an amount of about 2% by weight. 3. A method for preparation of a formulation for topical treatment of both acne and psoriasis comprising the steps of: 1) mixing purified water, edetate disodium, ascorbic acid and Carbomer 934P until the carbomer is dispersed to form a part I; 2) mixing purified water, Poloxamer 407 to form a part II; 3) adding part II to part I and homogenizing part I and part II; 4) mixing polyethylene glycol, Polysorbate 40, hexylene glycol, butylated hydroxytoluene and butylated hydroxyanisole and heating to dissolve same; 5) cooling the mixture of step 4) to room temperature and adding benzyl alcohol and Ethyl-6-[2-(4,4-dimethylthiochroman-6-yl] nicotinate thereto to form a part III; 6) mixing purified water and tromethamine to form part IV; 7) adding part III to parts I and II while stirring and thereafter adding part IV with mixing until homogeneous, said Polysorbate 40 being present in the formulation in an amount up to about 0.4% by weight, said Poloxamer 407 being present in the formulation in an amount up to about 0.4% by weight, and said hexylene glycol being present in the formulation in an amount up to about 2% by weight. 4. The formulation according to claim 3 wherein the Polysorbate 40 is present in an amount of about 0.32% by weight, the Poloxamer 407 is present in an amount of about 0.18% by weight, and the hexylene glycol is present in an amount of about 2% by weight. 5. A stable gel formulation for topical treatment of skin conditions in humans, said stable gel formulation comprising: an active agent having activity for treatment of acne and psoriasis, said active agent comprising: Ethyl-6-[2-(4,4-dimethylthiochroman-6-yl)-ethynyl]nicotinate; and nonaqueous vehicles for both solubilizing said active agent and forming a gel therewith, said nonagueous vehicles enabling topical application of the gel to a skin condition, said vehicles each being present in amounts, and in combination, to control release of the active agent from the gel to the skin condition, said nonaqueous vehicles comprising Polysorbate 40, Poloxamer 407 and hexylene glycol, said Polysorbate 40 being present in an amount up to about 0.4% by weight, said Poloxamer 407 being present in an amount up to about 0.4% by weight and said hexylene glycol being present in an amount up to about 2% by weight. 6. A stable gel formulation for topical treatment of skin conditions in humans, said stable gel formulation comprising: an active agent having activity for treatment of acne and psoriasis, said active agent comprising: Ethyl-6-[2-(4,4 dimethylthiochroman-6-yl)-ethynyl]nicotinate; and nonaqueous vehicles for both solubilizing said active agent and forming a gel therewith, said nonaqueous vehicles enabling topical application of the gel to a skin condition, said vehicles each being present in amounts, and in combination, to control solubility of the active agent in the gel, said nonaqueous vehicles comprising Polysorbate 40, Poloxamer 407 and hexylene glycol, said Polysorbate 40 being present in an amount up to about 0.4% by weight, said Poloxamer 407 being present in an amount up to about 0.4% by weight and said hexylene glycol being present in an amount up to about 2% by weight. 7. A stable gel formulation for topical treatment of skin conditions in humans, said stable gel formulation comprising: an active agent having activity for treatment of acne and psoriasis, said active agent comprising: Ethyl-6-[2-(4,4 dimethylthiochroman-6-yl)-ethynyl]nicotinate; and nonaqueous vehicles for both solubilizing said active agent and forming a gel therewith, said nonaqueous vehicles enabling topical application of the gel to a skin condition, said vehicles each being present in amounts, and in combination, to control both solubility of the active agent in the gel and the release of the active agent from the gel to the skin condition, said nonaqueous vehicles comprising Polysorbate 40, Poloxamer 407 and hexylene glycol, said polysorbate 40 being present in an amount up to about 0.4% by weight, said poloxamer 407 being present in an amount up to about 0.4% by weight and said hexylene glycol being present in an amount up to about 2% by weight. 8. The formulation according to claim 7 wherein the Polysorbate 40 is present in an amount of about 0.32% by weight, the Poloxamer 407 is present in an amount of about 0.18% by weight, and the hexylene glycol is present in an amount of about 2% by weight.