PERCUTANEOUSLY ABSORBABLE PREPARATION.

摘要

A percutaneously absorbable preparation which can long stably preserve a water-soluble drug capable of exhibiting the effect in a small dose and being readily decomposable, solid at ordinary temperature and difficultly absorbable percutaneously and which can sustainedly release the drug percutaneously at a high rate when applied to the skin. The preparation comprises a drug store layer wherein a drug is incorporated and a drug release control membrane for coating the drug release surface of the drug store layer. This layer is made from a heat-sensitive segmented polyurethane which is represented by the following general formula: R-A-(U)-F-(U)-B-R', (wherein A and B represent each a homopolymer or a random or block copolymer of ethylene oxide, propylene oxide, tetramethylene oxide or 1,2-butylene oxide; R and R' represent each H, CH3, C2H5, C3H7 or C4H9 as the terminal of each of A nad B; A=B or A NOTEQUAL B; R=R' or R NOTEQUAL R'; F represents the residue of a diisocyanate compound; and (U) represents a urethane bond) and wherein at least one of A and B is hydrophilic and at least one of them will melt near the human skin temperature. The drug release control membrane comprises a phase-separation membrane wherein a cross-linked gelatin phase and a non-cross-linked segmented polyurethane phase are intermingled.