CONCERNS AND LIMITATIONS OF MATERIALS FOR ORAL DELIVERY OF INSULIN

Insulin is commonly administered to diabetic patients sub-cutaneously and has shown poor patient compliance. The problem lies with the delivery of proteins and peptides to the body, for which oral, transdermal, vaginal, rectal, and pulmonary routes have been explored for proteins like insulin. Still, so far subcutaneous route has delivered the best results. This results in fear of the patients due to the prick caused by the subcutaneous delivery. To overcome these nuances, work has been carried out on delivering insulin orally. Different molecules have been extensively studied to deliver insulin orally. This review article covers the various materials exploited for the delivery of peptides like insulin, viz. polymers, nanoparticles, liposomes, and many more that have been evaluated as a vehicle for the oral delivery of insulin. Polymers that are naturally obtained like chitosan and its subsidiaries, alginates, γ-PGA based materials, starch-based nanoparticles, and manufactured polymers like PGLA, P(MAA-g-EG), PLA, PEA Poly(alkyl cyanoacrylate) Nanoparticles, Solid Lipid Nanoparticles, Targeted Nanoparticles and Gold Nanoparticles have been discussed for a better understanding of oral delivery.