The Hidden Obstacles to Intranasal Insulin Delivery: A Narrative Review.

A large number of people are suffering with one or the other type of diabetes around the globe. Insulin has proven to be beneficial for the treatment of both types of diabetes. Due to the drawbacks (injection pain, needle phobia, lipodystrophy, noncompliance peripheral hyperinsulinemia, failure to deliver physiological pattern of insulin, and daily metabolic variability in glycemic control) associated with a conventional delivery system that is, the subcutaneous injection, a need to develop new insulin delivery system was felt strongly. A few noninvasive methods which are under process to deliver insulin include per-oral (enteric gastrointestinal route), intrapulmonary, buccal, intranasal, oropharyngeal, rectal, intrauterine, ocular, transdermal, oral, and vaginal. Intranasal insulin is fetching tons of importance as it provides multiple reasons to choose this method of delivery over other delivery systems. Certain factors are responsible for limiting the use of intranasal insulin for which various methods have been studied to overcome it. Many clinical trials are going on for launching intranasal insulin into the market. [ABSTRACT FROM AUTHOR]