USE OF POLY(ORTHO ESTERS) AND POLYANHYDRIDES IN THE DEVELOPMENT OF PEPTIDE AND PROTEIN DELIVERY SYSTEMS

This brief review summarizes the use of poly(ortho esters) and polyanhydrides in the controlled release of peptides and proteins. Poly(ortho esters) have been used for the controlled release of an LHRH analogue, in the development of an insulin self-regulated drug delivery system and in the development of vaccines, using lysozyme as a model protein. Polyanhydrides based on fatty acid dimers and sebacic acid have been used for the controlled release of a variety of proteins and linear release over a one moth period was achieved. Poly(ortho esters) and polyanhydrides offer a number of advantages over the more commonly used lactide/glycolide copolymers since they offer better control over polymer properties and erosional behavior. Poly(ortho esters) may offer an additional advantage in that Initial hydrolysis products are neutral so that liberation of acidic primary hydrolysis products which are inherent in the hydrolysis of both lactide/glycolide copolymers and polyanhydrides may not be a problem.