Polymerosomes of PCL and PEG Demonstrate Enhanced Therapeutic Efficacy of Insulin

Abstract

The objective of the study was to evaluate the efficacy of insulin loaded polymerosomes in diabetic rat model. To achieve the purpose, amphiphilic triblock co-polymers of the class poly(caprolactone)-poly(ethylene glycol)-poly(caprolactone), CEC were synthesized by ring-opening polymerization and characterized. Polymerosomes were prepared by double emulsion method in the size range of 75-130 nm at 25 °C as measured by differential light scattering technique. Insulin was loaded in situ during nanoparticle preparation. The release of insulin was observed to be critically dependent on the caprolactone/ethylene glycol ratio and particle size. The pharmacological activity ranged from 22-36 h for various polymerosomes formulations in comparison to poly(caprolactone), PCL nanoparticles which reached the basal level after 4 h of administration. The polymerosomes were therefore seen to enhance the insulin activity as well as its stability in physiological fluid for a prolonged duration. Keywords: Polymerosomes, poly(caprolactone), poly(ethylene glycol), insulin, release behaviour, in vivo evaluation