The impact of natural and synthetic polymers in formulating micro and nanoparticles for antidiabetic drugs

Diabetes mellitus is one of the long known chronic diseases, today over 400 million people are diagnosed with diabetes. Yet curing diabetes is a challenge. Over the decades, the approaches of treating diabetes mellitus have evolved and polymeric materials have played an integral part in developing and manufacturing anti-diabetic medications. However, injection of insulin remains the conventional therapy for the treatment of diabetes. Oral administration is generally the most preferred route; yet, physiological barriers lead to a challenge for the formulation development for oral delivery of antidiabetic peptide and protein drugs. This present review focuses on the role of different types of biodegradable polymers (e.g., synthetic and natural) that have been used to develop micro and nano particles based formulations for antidiabetic drugs (Type 1 and Type 2) and how the various encapsulation strategies impact its therapeutic effect, including pharmacokinetics studies, drug release profiles and efficacy of the encapsulated drugs. This review also includes studies of different dosage forms such as oral, nasal, inhalation and sublingual for the treatment of diabetes that have been investigated using synthetic and natural biodegradable polymers in order to develop an alternative route to subcutaneous route for a better control of serum glucose levels.