Poly(lactic-co-glycolic acid) - polyethylene glycol copolymer for long-acting injectable: Synthesis, characterization, and in-vivo study

This work was aimed to develop a carrier system of Poly(lactic-co-glycolic acid) (PLGA) by using Polyethylene glycol (PEG) for longer action in various diseases by preparing a di-block copolymer by using Risperidone (RSP) as a drug. PLGA-PEG copolymer was synthesized, which can be used to prepare nano particles like polymeric micelles and gets circulated longer time in body. The preparation of copolymer was then confirmed with 1HNMR. Molecular weight was confirmed by Mass spectroscopy. The polymeric micelles were prepared by single emulsion method. The polymeric micelles were characterized for particle size, zeta potential in vitro release and in vivo study. The results of experiment show that copolymer can be prepared by ring opening polymerization. Proton nuclear magnetic resonance (1HNMR) and Fourier-transform infrared spectroscopy (FTIR) were consistent with the structure. The entrapment efficiency was around 80%, zeta potential was -0.5mV, particle size was found to be 163nm (±5). Risperidone release from polymeric micelles showed initial burst and then sustained and controlled release. In-vivo studies were done for 7 days in rats and showed extention of 12 folds in half life of Risperidone. Thus, PLGA-PEG polymeric micelles can be effective carrier for drug delivery system.