Since Banting and Best first isolated Insulin in 1922, much progress has been made in its formulations (e.g. : long acting Insulins and Insulin analogues) and its delivery (e.g. via insulin pumps etc) however the subcutaneous route has remained the only option for administering it on long term basis. Every day millions of Diabetic patients around the world bear the burden of multiple subcutaneous injections of Insulin and this has led the scientists to continuously search for non-invasive modes of Insulin administration.

As early as 1971, Wigely et al showed that regular Insulin can be administered as an aerosol via a Nebuliser. Since then a number of Inhaled Insulins have been tried in clinical trials. In Jan. 2006, US FDA approved Insulin EXUBERA as the first inhaled Insulin for treatment of both type I and II diabetes mellitus, however other similar products in phase III trials are in the pipeline. Inhaled Insulins are as effective as Sub-cutaneous insulin and it works similarly to rapid acting Insulin as far as in its onset and duration of action is concerned.

The most common side effect observed in clinical trials was cough and it was shown to cause slight reduction in FEV1 and DLco but this occurred early, and was minimal and non-progressive, however larger trials of sufficiently long duration are needed to determine its pulmonary safety. The measures of patient’s satisfaction and quality of life showed that inhaled Insulins are well received in various populations of patients with diabetes. The article will review the efficacy and safety of inhaled Insulins with particular reference to Exubera Insulins