Insulin (medication) to develop an orally available insulin. Many of these approaches employ nanoparticle delivery systems and several are being tested in clinical trials. Another improvement would be a transplantation of the pancreas or beta cell to avoid periodic insulin administration. This would result in a self-regulating insulin source. Transplantation of an entire pancreas (as an individual organ) is difficult and relatively uncommon. It is often performed in conjunction with liver or kidney transplant, although it can be done by itself. It is also possible to do a transplantation of only the pancreatic beta cells. However, islet transplants had been highly experimental
NPH insulin action, which is the primary reason NPH remains on the market today, because manufacturers sell a variety of premixed insulin formulations. Eventually all animal insulins made by Novo Nordisk were replaced by synthetic, recombinant 'human' insulin. Synthetic 'human' insulin is also complexed with protamine to form NPH. It has an intermediate duration of action, meaning longer than that of regular and rapid-acting insulin, and shorter than long acting insulins (ultralente, glargine or detemir). NPH insulin may be combined with faster acting insulin to allow more accurate dosing and better blood sugar level control. When administered this way, the two insulin