A review of non-invasive insulin delivery systems for diabetes therapy in clinical trials over the past decade.

At present, the main form of insulin administration is the invasive subcutaneous (s.c.) route and, for many patients, this means managing their glucose levels with multiple daily injections, which is both painful and difficult to administer chronically. To increase patient compliance, products are slowly reaching the market that are more patient friendly, such as the insulin patch-pump systems, including Omnipod and V-Go, but also the inhaled-insulin Afrezza® and the buccal insulin Oral-lyn™. In this review, we outline the history of insulin, the various options that are currently available in practice for insulin delivery, and the non-invasive delivery systems that have entered the different stages of clinical trials over the past decade.