Insulin Analogs and the Mode of Insulin Delivery: Recent Advances and Challenges

Diabetes is a medical condition associated with impaired glucose regulation caused either due to insufficient insulin production or resistance to insulin (Type 2 diabetes, gestational diabetes) or the absence of insulin through the selective killing of beta cells in the pancreas (Type 1 diabetes). Irregular insulin production leads to various health complications. To prevent such complications, patients must adhere to medical recommendations before availing of any advanced insulin therapy(ies), considered productive for the treatment. Natural insulin, although highly effective in controlling blood glucose levels, patients are often at risk of developing hypoglycemia and many other complications. This has led to the development of insulin analogs, the modified variants of natural insulin having a minimal risk of causing hypoglycemia. Besides the development of analogs, the mode of insulin delivery is also considered critical in achieving better glycemic control in diabetic patients. Until recently, various exogenous insulin delivery methods were practiced, but effective glycemic control without any associated risk and ease of delivery remains a subject of paramount concern. It countered attenuation or delayed onset of diabetes-associated complications without a permanent cure, raising an unmet demand for insulin formulations and delivery methods that offer stability, biocompatibility, reproducibility, precision dosing, non-immunogenicity, and safety. The current practice utilizes non-physiological delivery methods with less invasive administration routes, offering glycemic stability and therapeutic effectiveness. This review focuses on the recent advances made and future perspectives envisioned about newer insulin therapies and delivery methods that tend to improve the management of diabetes by inculcating ideas to reduce the disease's severity and improve the quality of life.