ORAL CONTROLLED-RELEASE TECHNOLOGY FOR PEPTIDES - STATUS AND FUTURE-PROSPECTS

In spite of significant efforts in academic and commercial laboratorie s, major breakthroughs in oral peptide and protein formulation have no t been achieved. The major barriers to developing oral formulations fo r peptides and proteins include poor intrinsic permeability,, lumenal and cellular enzymatic degradation, rapid clearance, and chemical and conformational stability. pharmaceutical approaches to address these b arriers, which have been successful with traditional, small, organic d rug molecules, have not readily translated into effective peptide and protein formulations. The success achieved by Sandoz with cyclosporin formulations remains one clear example of what can be achieved, althou gh it is likely that effective oral formulations for peptides and prot eins will remain highly compound specific. Although the challenges are significant, the potential therapeutic benefit remains high, particul arly with the increasing identification of potential peptide and prote in drag candidates emerging from the biotechnology arena. Successful f ormulations will most likely require a systematic and careful merger o f formulation and design delivery systems which maximize the potential for absorption across the epithelial cell layer.