METHOD FOR FORMING CONTROLLED RELEASE POLYMERIC SUBSTRATE

摘要

A method for forming a controlled release polymeric substrate is provided by contacting a polymeric substrate with a liquid mixture containing a cross-linking agent at least partially soluble therein comprising water and an organic liquid, for a period of time and at a temperature and concentration of the agent sufficient for the agent to penetrate the substrate to form cross-linking bridges in the substrate in a decreasing concentration gradient beneath the surface.