Developments in polymeric devices for oral insulin delivery

Background: Development of improved oral insulin administration is necessary for the treatment of diabetes mellitus, to overcome the problem of daily subcutaneous injections. The vast amount of literature data on oral insulin delivery prompted us to cover this area in a review. Objective: Insulin delivery using polymeric devices is discussed, with an ultimate aim of addressing the technological development in this area. Methods: The development of oral delivery devices for insulin using hydrogels and micro/nanoparticles is discussed with reference to polymers. These efforts must be directed to increase the residence time of insulin near the intestinal absorptive cells. Results/conclusion: The published results on oral insulin delivery devices, particularly on inter-polymer complexes of the grafted copolymers, are discussed in greater depth. The use of absorption enhancers like cyclodextrins, bile salts and surfactants is covered. The state-of-the-art technology and challenges in this area are discussed, with typical examples.