Prodrug strategies to enhance the intestinal absorption of peptides

Clinical development of orally active peptide drugs has been restricted by the unfavorable physicochemical properties of these molecules limiting intestinal mucosal permeation and the lack of stability of peptides against enzymatic degradation. Successful oral delivery of pep tides will depend, therefore, on strategies designed to alter the physicochemical characteristics of these potential drugs,without changing their biological activity, in order to increases the permeation across intestinal cells. This manuscript will focus on the biological barrier properties that limit oral peptide bioavailabiiity and on prodrug strategies designed to overcome these barriers.