Encapsulation Efficiency and Release of Green Tea Polyphenols from Poly (Lactic Acid)-Poly (Ethylene Glycol) Nanoparticles are Controlled by the ratio of Poly (Lactic Acid)/Poly (Ethylene Glycol)

Introduction: Despite several health benefits of green tea polyphenols (GTP), its use as a therapeutic agent has been constrained by instability, biotransformation and poor bioavailability. Objective: In our study, GTP was encapsulated in nanoparticles prepared from different ratios of poly (lactic acid) (PLA)/poly (ethylene glycol) (PEG). Methods: GTP loaded nanoparticles were synthesized and characterized. In vitro drug GTP release was carried out followed by determining drug release kinetics and the mechanism of release. Results: Nanoparticles of 95-175 nm were observed through AFM, SEM and were further characterized through XRD and FTIR. PLA/PEG ratio influenced the encapsulation efficiency (EE) and release of GTP from PLA-PEG nanoparticles. Nanoparticles prepared from PLA/PEG ratio of 3:1 showed maximum EE at GTP concentration of 12 mg/ml, with optimum ratio of polymer/drug being 8:1. Burst release of GTP was observed till 8 h, followed by sustained release at different pH, temperature and GTP concentrations at a PLA/PEG ratio of 3:1. Most of the release data were fitted into Zero order kinetics with a Fickian release and were not influenced by PLA/PEG ratio. Conclusion: It was observed that PLA-PEG nanoparticulate system at a ratio of 3:1 could be a potent carrier for achieving a sustained release of GTP. All these data indicated that EE and release of GTP from PLA-PEG nanoparticles were controlled by PLA/ PEG ratio.