Nanoparticles for Oral Delivery of Insulin

Abstract

The development of insulin nanoparticles (NP) in addition to protecting insulin against a harmful gastric environment can avoid its enzymatic degradation, while controlling its release and enhancing its absorption in the small intestine. The enhancement of oral bioavailability of nanoencapsulated insulin has been demonstrated in animal studies. However, the question is why they were not followed by industrial development and clinical trials is still open. The variability of the insulin concentration delivered to the blood, the low bioavailability of encapsulated insulin requiring the administration of high doses and the lack of uptake mechanisms evidence, represent handicaps for the development of such delivery systems. Administration of such high doses of insulin transcellularly may induce mitogenic changes in the gastrointestinal epithelium, as insulin is a growth factor. Current NP systems must be improved both to increase the insulin loading and to lower the insulin dose required to produce a therapeutic glycemia reduction. (copyright) Springer Science+Business Media Dordrecht 2013.