ADVANCES IN THE ORAL DELIVERY OF PROTEINS

Due to their low oral bioavailability, most protein drugs are only ava ilable as parenteral formulations. The oral delivery of proteins is ch allenging and has often been considered an unattainable goal; neverthe less, the efforts to develop oral formulations of proteins continue to be numerous. The approaches devised to overcome the obstacles for the absorption of proteins from the gastrointestinal tract are various, a nd include the co-administration of enzyme inhibitors and/or absorptio n enhancers, the encapsulation in liposomes, microemulsions, or biodeg radable particles, and the modification of proteins through the attach ment of chemical moieties. This article reviews the recent patent lite rature related to formulation strategies to improve the oral bioavaila bility of proteins.