Medical patches and processes for producing same

Abstract

A layer or member particularly useful as part of a medical patch such as an anisotropic wound dressing, a transdermal skin patch or an incise medical drape and the processes for forming such a member. The member is comprised of a crosslinked thermoset aliphatic polyurethane elastomer. The elastomer is the reaction product of (1) isophorone diisocyanate, (2) a macroglycol and (3) a chain terminator having both hydroxyl and vinyl functional groups. Polycarbonate glycols or polyetherglycols having a molecular weight of 500-2500 Daltons are preferred macroglycols and isophorone diamine is a preferred chain terminator. In one embodiment, a member or polyurethane layer for use as a wound dressing or an incise medical drape is produced by applying a film-forming solution or dispersion as a thin film to a supporting release paper and treating the film to drive off the liquids and to activate a crosslinker. In another embodiment, a member for an anisotropic medical patch is produced by sandwiching a knitted reinforcing fabric in the elastomer. When used as a transdermal skin patch or a drug dispensing wound dressing, a layer of drug dispensing film containing pharmacoactive agents may be applied to the medical patch, and when appropriate, the medical patch may be coated with a pressure sensitive adhesive.