Is there an impact of encapsulation on parenteral delivery of insulin?

Abstract

Diabetes mellitus is a chronic metabolic disorder with epidemic proportions which is characterized by chronic high blood glucose levels as a result of the inefficient insulin action. It is classified in different types, such as type 1 and type 2, and its development depends on several factors, such as lifestyle and genetic factors. For insulin-dependent diabetics the administration of insulin is the only available therapy. Insulin therapy, as other protein therapies, is challenging due to protein properties, such as susceptibility to physical and chemical degradation and short in vivo half-life, and, therefore its delivery has to be made by parenteral route. Since it began, insulin therapy has evolved trying to better mimic the physiological profile of insulin action in healthy individuals. As some limitations still compromise the efficiency of insulin therapy, encapsulation of insulin has been proposed in order to improve its long-term delivery by parenteral route. In the present thesis a brief review of the evolution of insulin therapy since its beginning will be made. It is intended to identify the main disadvantages of current insulin therapy. Also, the potential application of nanotechnology in insulin delivery will be addressed. The encapsulation of insulin into polymeric particles and its effect in the control of blood glucose levels after parenteral administration will be also discussed.