Insulin is a peptide hormone produced by the pancreas and is central to regulating carbohydrate and fat metabolism in the body. Insulin therapy is used for the treatment of people with type 1 diabetes in order to avoid complications arising from hyperglycemia. Insulin is administered mainly through subcutaneous insulin injections such as vials and syringes, insulin pens, and insulin pumps. In addition to this, various other physiological minimally invasive or noninvasive ways for delivering insulin are oral, buccal, nasal, peritoneal and transdermal.