Abstract

Although most protein pharmaceuticals are usually formulated as a solution or suspension and delivered by invasive routes such as subcutaneous injections, major efforts in both academic and industrial laboratories have been directed towards developing effective oral formulations and increasing the oral absorption of intact protein through the use of formulations that protect the macromolecule and/or enhance it's uptake into the intestinal mucosa. However, in spite of these major attempts, relatively little progress has been made. For the efficient delivery of peptides and proteins by non-parenteral route, in particular via the gastrointestinal tract, novel concepts are needed to overcome significant enzymatic and diffusion barriers. The properties of protein and peptides, which are of major interest in oral delivery, are highlighted in the article. This article reviews the various problems associated and novel approaches for formulation and development of oral protein and peptide drug delivery systems.