[Recent trends on clinical development of oral insulin delivery systems].

Great effort for developing effective needle-free insulin delivery technology, especially oral delivery, has been continued in worldwide, indeed, from the era of insulin discovered. Oral administration of insulin would offer not only the potential for improved patient compliance but also improved safety/efficacy in certain instances. Much effort for developing noninvasive delivery systems of insulin has been done, and recently, several promising insulin oral formulations are entered into clinical trials. Delivering insulin in orally was major challenge, but its realization is surely approaching. This review provides an update on recent approaches that have shown promise in insulin oral delivery systems. In addition, the progress of basic research in noninvasive delivery system research for biopharmaceuticals is discussed.