Claims for Patent: 5,827,529

Summary for Patent: 5,827,529

Title:	External preparation for application to the skin containing lidocaine
Abstract:	An external preparation for application to the skin containing lidocaine which comprises a drug-retaining layer placed on a support, wherein said drug-retaining layer comprises an adhesive gel base and 1 to 10% by weight of lidocaine, said base comprising a water-soluble high molecular weight substance, water and a water-retaining agent, which can release the active lidocaine gradually and constantly so that lidocaine is transdermally absorbed for a long period of time.
Inventor(s):	Ono; Masahiro (Kagawa-ken, JP), Akazawa; Mitsuji (Kagawa-ken, JP), Seki; Michiko (Kagawa-ken, JP), Iwamoto; Kiyomi (Kagawa-ken, JP), Konishi; Ryoji (Kagawa-ken, JP)
Assignee:	Teikoku Seiyaku Kabushiki Kaisha (Kagawa-Ken, JP)
Application Number:	08/258,378
Patent Claims:	1. An external preparation for application to the skin containing lidocaine which comprises a drug-retaining layer placed on a support, wherein said drug-retaining layer comprises an adhesive gel base and 1 to 10% by weight of lidocaine, said base consisting essentially of 0.5 to 50% by weight of a water-soluble high molecular weight substance selected from the group consisting of gelatin, starch, agar, mannan, alginic acid, polyacrylic acid, a salt of polyacrylic acid, dextrin, methylcellulose, methylcellulose sodium, carboxymethylcellulose, carboxymethylcellulose sodium, polyvinyl alcohol, polyvinyl pyrrolidone, copolymer of methyl vinyl ether and maleic anhydride, gum arabic, tragacanth, karaya gum and locust bean gum, 30 to 70% by weight of water and 1 to 70% by weight of a water-retaining agent selected from the group consisting of ethylene glycol, diethylene glycol, polyethylene glycol, glycerin, sorbitol, martitol, propylene glycol and 1,3-butylene glycol, said lidocaine being dissolved in the base so as to result in a uniform base material. 2. The external preparation of claim 1 wherein said adhesive gel base is capable of controlling the release of drug and has a pH value of 5 to 9. 3. The external preparation of claim 1 wherein the water content of said adhesive gel base is 20 to 50% by weight. 4. The external preparation according to claim 1, wherein said adhesive gel base consists essentially of 0.5 to 50% by weight of a water-soluble high molecular weight substance selected from the group consisting of gelatin, starch, agar, mannan, alginic acid, polyacrylic acid, a salt of polyacrylic acid, dextrin, methylcellulose, methylcellulose sodium, carboxymethylcellulose, carboxymethylcellulose sodium, polyvinyl alcohol, polyvinyl pyrrolidone, copolymer of methyl vinyl ether and maleic anhydride, gum arabic, tragacanth, karaya gum and locust bean gum, 30 to 70% by weight of water and 1 to 70% by weight of a water-retaining agent selected from the group consisting of ethylene glycol, diethylene glycol, polyethylene glycol, glycerin, sorbitol, martitol, propylene glycol and 1,3-butylene glycol; an absorbing agent and a surfactant, said lidocaine being dissolved in the base so as to result in a uniform base material. 5. The external preparation of claim 4 wherein said absorbing agent is selected from the group consisting of salicylic acid, hyaluronic acid, oleic acid, N,N-diethyl-m-toluamide, n-butyl stearate, benzyl alcohol, isopropyl myristate, isopropyl palmitate, polypropylene glycol, crotamiton, diethyl sebacate, N-methylpyrrolidone, N-ethylpyrrolidone and lauryl alcohol, and said surfactant is selected from the group consisting of polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monostearate, sorbitan monooleate and sorbitan monopalmitate. 6. The composition according to claim 1, wherein said water is present in an amount of 34.55% to 70% by weight.