The preparation, characterization of Lupeol PEGylated liposome and its functional evaluation in vitro as well as pharmacokinetics in rats

Objective: The objective of this study was to enhance the solubility and bioavailability of Lupeol. Methods: Utilizing a thin-film dispersion method, we prepared Lupeol-loaded PEGylated liposomes and Lupeol-loaded liposomes, which was characterized using SEM, mean diameter, PDI, zeta potential, and entrapment efficiency (EE). The EE, in vitro release, and stability of Lupeol-loaded PEGylated liposomes were detected using HPLC. In addition to the safety evaluation, the evaluation was carried out on HepG2 cells in vitro; the pharmacokinetics were carried out after i.v. in the rats. Results: The size, PDI, zeta potential, and EE of Lupeol-loaded PEGylated liposomes and Lupeol-loaded liposomes were 126.9 nm, 0.246, -1.97 mV, 87%; 97.23 nm, 0.25, 1.6 mV, 86.2%, respectively. Lupeol-loaded PEGylated liposomes showed the slow-release effect in vitro release experiments. Lupeol-loaded PEGylated liposomes offered significant advantages over other experimental groups in vitro studies, such as the highest inhibition rate and the highest apoptosis rate. We also found that Lupeol-loaded PEGylated liposomes blocked cells in the G2M phase. The pharmacokinetics result showed that the AUC of Lupeol-loaded PEGylated liposomes group was 3.2 times higher than free Lupeol group after i.v., the MRT and t1/2 values of Lupeol-loaded PEGylated liposomes (MRT = 6.09 h, t1/2 =12.94 h) showed improvements of 2.5 and 4.1 times compared to free Lupeol (MRT = 2.43 h, t1/2 = 3.16 h). Conclusion: The Lupeol-loaded PEGylated liposomes have successfully solved its poor hydrophilicity, low bioavailability.