A review of reusable insulin pens and features of TouStar-a new reusable pen with a dedicated cartridge.

Background: Since the introduction of the first reusable insulin pen, the advancement in the design of these pens is still ongoing to develop a safe, more efficacious, less painful, and easy to use insulin pen device.

Main Body: Possible errors in insulin delivery can occur at any stage of insulin delivery such as during the prescription stage, dispensing stage, or at administration stage. Mismatch of the insulin pen and cartridge is not uncommon and is a potential risk for individuals with diabetes due to serious consequences associated with incorrect insulin usage.