Varshney H. M., Rajnish kumar, Shailender Mohan

 Diabetes mellitus is a serious pathologic condition which is responsible for major
healthcare problems worldwide and costing billions of dollars annually. Insulin replacement
therapy has been used in the clinical management of diabetes mellitus for more than
84 years. Insulin has remained indispensable in the management of diabetes mellitus since its discovery in 1921. Comparatively, a large percentage of world population is affected by
diabetes mellitus, out of which approximately 5-10% with type 1 diabetes while the remaining 90% with type 2. The present mode of insulin administration is by the subcutaneous route through which insulin is introduced into the body in a non-physiological
manner having many challenges. Hence novel approaches for insulin delivery are being
explored. Challenges that have adverse effect on oral route of insulin administration mainly includes: rapid enzymatic degradation in the stomach, inactivation and digestion by proteolytic enzymes in the intestinal lumen and poor permeability across intestinal epithelium because of its high molecular weight and lack of lipophilicity. Approaches such as liposome, micro emulsions, nanocubicle, insulin chewing gum and so forth have been prepared to ensure the oral delivery of insulin. Attempts have been made to achieve oral insulin delivery using various systems. Scientists have been able to protect the insulin delivery systems from acidic environment of the stomach and target it to the intestine.
Limitations to the delivery of insulin have not resulted in fruitful results to date and there is still Keywords: Diabetes mellitus, Liposome, Microemulsions, Nanocubicle, Oral insulin
delivery systems.