Preparation, optimization, characterization and cytotoxicity in vitro of Baicalin-loaded mixed micelles

Abstract The aim of this study was to develop a Baicalin (BC)-loaded mixed micelle delivery system (BC–ST–P123–MMs) with sodium taurocholate (ST) and pluronic P123 block copolymer (P123) as carrier materials to improve the solubility of BC, a poorly soluble drug. In this study, the mixed micelle system was prepared using the method of thin-film dispersion and then optimized by the homogeneous design–response surface methodology with the entrapment efficiency and drug loading as indexes. The average size and the zeta potential of the BC–ST–P123–MMs were 15.60 nm and −5.26 mV, respectively. Drug loading (DL, 16.94%) and entrapment efficiency (EE, 90.67%) contributed to high solubility (10.20 mg/mL) of BC in water. The optimized BC–ST–P123–MMs appeared spherical with obvious core–shell structure and well dispersed without aggregation and adhesion under TEM. In addition, DSC result indicated that BC had been wrapped in BC–ST–P123–MMs and crystalline state of BC was changed. The release result in vitro showed that BC–ST–P123–MMs presented sustained release behavior compared to control group. The IC 50 value of BC–ST–P123–MMs (46.18 μg/mL) was lower than that of BC solution (67.14 μg/mL) on Hep G2 cell lines. Cellular uptake tests illustrated that the ST–P123–MMs system as carrier could significantly enhance the uptake of drugs by tumor cells. The results demonstrated that the BC-loaded mixed micelles could improve solubility of BC and exhibited great potential for delivering drug into cancer cells.