In Vitro Characterization of Resveratrol-Loaded Pluronic Micelles

Abstract

Resveratrol (RES), a polyphenol has shown various biological activities but its use is hindered due to its hydrophobicity and short biological half-life. Biological studies require mega or frequent doses of RES to be effective. Pluronics® F88, F98, F108 and F127 form polymeric micelles & can be used to deliver RES. Micelles were prepared by equilibrium (E) or solvent casting (SC) with either 10 % or 20 % w/w RES loading. Micelles prepared by E of 20% w/w RES showed a correlation with the critical micelle concentrations of the Pluronic® used. Micelles prepared by SC with 10 % w/w RES were stable for 48 hr and approached equilibrium solubility over 12 days. Micelles prepared by SC with 20 % w/w RES were able to fully solubilize RES but approached equilibrium solubility rapidly. Cytotoxicity (IC50) studies in human ovarian cancer cell line, SK-OV3 using RES and all Pluronic® micellar formulations with 10 % w/w RES were done. RES alone had IC50 values of 92.00 ± 17.24 μM RES Pluronic® formulations F88, F98, F108 & F127 had IC50 values of 49.69 ± 9.28 μM, 84.57 ± 7.48 μM, 53.12 ± 11.45 μM and 79.15 ± 21.84 μM respectively, indicating slightly greater potency than RES alone. In conclusion, RES Pluronic® formulations prepared by SC form meta-stable systems of different stabilities based on initial loading. Cytotoxicity studies show all RES formulations are at least as potent as RES alone.