Controlled release oral drug delivery system

Abstract

The present invention relates to a controlled release drug delivery system comprising a drug which is susceptible to enzymatic degradation by enzymes present in the intestinal tract; and a polymeric matrix which undergoes erosion in the gastrointestinal tract comprising a hydrogel-forming polymer selected from the group consisting of (a) polymers which are themselves capable of enhancing absorption of said drug across the intestinal mucosal tissues and of inbihiting degradation of said drug by intestinal enzymes; and (b) polymers which are not themselves capable of enhancing absorption of said drug across the intestinal mucosal tissues and of inhibiting degradation of said drug by intestinal enzymes; wherein when the matrix comprises a polymer belonging to group (b) the delivery system further comprises an agent which enhances absorption of said drug across the intestinal mucosal tissues and/or an agent which inhibits degradation of said drug by intestinal enzymes and when the matrix comprises a polymer belonging to group (a) the delivery system optionally further comprises an agent which enhances absorption of said drug across the intestinal mucosal tissues and/or an agent which inhibits degradation of said drug by intestinal enzymes.