A REVIEW ON ORAL INSULIN

Abstract

Diabetes mellitus is a serious pathological condition that is responsible for major healthcare problems worldwide. Insulin is a proteinaceous hormone produced in the islets of Langerhans in the pancreas and used as a treatment in diabetes mellitus. The present mode of insulin administration is by subcutaneous route through which insulin is presented to the body in non-physiological manner having many challenges. Hence novel approaches for insulin delivery are being explored. Oral insulin is one of the most exciting areas of development in the treatment of diabetes because of its potential benefit in patient convenience, rapid insulinization of liver, adequate insulin delivery avoiding peripheral hyperinsulinaemia while potentially avoiding adverse effects of weight gain and hypoglycaemia. Challenges to oral route of in administration are: rapid enzymatic degradation in the stomach, inactivation and digest by proteolytic enzyme in the intestinal lumen and poor permeability across intestinal epithelium because of its high molecular weight and lack of lipophilicity. Successful oral insulin delivery involves overcoming the enzymatic and physical barriers and taking steps to conserve bioactivity during formulation processing. There is still a need to prepare newer delivery systems, which can produce dose-dependent and reproducible effects, in addition to increase bioavailability.