Abstract
There are more than 246 million patients with diabetes mellitus in the world. Approximately 10∼15% of them suffer from diabetes mellitus type I, which is characterized by deficit of insulin synthesis in pancreas. Type 1 is lethal unless treated with exogenous insulin. Injection is the traditional and still most common method for administering insulin;jet injection, indwelling catheters. Therefore, the quest to eliminate the needle from insulin delivery and to replace it with non- or less-invasive alternative routes has driven rigorous pharmaceutical research to replace the injectable forms of insulin. Recently, various approaches have been studied involving many strategies using various technologies have shown success in delivering insulin, which are designed to overcome the inherent barriers for insulin uptake across the gastrointestinal tract, mucosal membranes and skin. This review examines some of the many attempts made to develop alternative, more convenient routes for insulin delivery to avoid existing long-term dependence on multiple subcutaneous injections and to improve the pharmacodynamic properties of insulin. In addition, this review summarized the noninvasive technologies and devices that succeeded in commercialization, and also focused on major new milestones in modern insulin delivery for the effective treatment of diabetes.
