The purpose of this study was to develop a liquid self-assemble proliposome for quercetin oral delivery. This liquid proliposome was prepared by dissolving phospholipids, surfactants and drug in ethanol. There was only one step in the preparation process of this liquid self-assemble proliposome and no special devices were required. The mechanism about proliposome transformation was discussed. Quercetin proliposomes with different cremorphor RH40 concentrations (0%, 20%, 23%, 26%, 30%) were prepared. The particle size and polydispersity index decreased as cremorphor RH40 concentration increased. Meantime, the drug entrapped efficiency decreased slightly with an increase in cremorphor RH40 concentration. The in vitro drug release showed prolonged drug release in case of proliposome and the release of quercetin was slower when cremorphor RH40 concentration was higher. The absorption of quercetin and its in vivo bioavailability were significantly improved by proliposome, which was evidenced by the in situ intestinal absorption and pharmacokinetic study. Besides, the obtained quercetin proliposome was with good stability when stored at room temperature. In conclusion, quercetin liquid self-assemble proliposome was successfully prepared. It could transform into liposomal vesicle with satisfied particle size and polydispersity index instantly when cremorphor RH40 was added. Cremorphor RH40 concentration in the formulation should below 26% to get higher drug entrapped efficiency (>90%) and less irritation. The drug release was affected by the cremorphor RH40 concentration and the required drug release could be obtained by adjusting cremorphor RH40 content. The enhanced bioavailability showed liquid self-assemble proliposome could be a promising vehicle for the oral delivery of quercetin.
Keywords: Absorption improved; cremorphor RH40; self-assemble proliposome; surfactant; sustained release.