| Abstract: | Quercetin (QUE) has many beneficial biological activities and pharmacological actions in vitro. However, its oral bioavailability in vivo was very poor due to poor solubility, and severely restricted its clinical applications. In this study, we preparedquercetin solid dispersion (QUE-SD) and quercetin phospholipids complex solid dispersion (QUE-PC-SD) by a solvent evaporationmethod to improve the absorption of QUE in vivo. The results of XRD of QUE-SD and QUE-PC-SD showed that QUE was dispersed homogeneously in an amorphous or molecular state in QUE-SD and QUE-PC-SD, which could contribute to improve the solubility and dissolution of QUE. The solubility of QUE-SD and QUE-PC-SD was enhanced from (4.03±0.02) μg/mL to (26.91±0.06) μg/mL and (30.65±0.06) μg/mL, respectively. The solubility of QUE-PC-SD was higher than that of QUE-SD.In vitro dissolution study, it was showed that the maximum dissolution of QUE (9.57%) from the QUE-SD and QUE-PC-SD was enhanced to 93.81% and 94.16%, respectively. The results of pharmacokinetic experiment indicated that the QUE-SD and QUE-PC-SD exhibited considerable enhancement in the oral bioavailability. The relative bioavailability of QUE-SD and QUE-PC-SD compared with QUE were 149.49% and 198.32%, respectively. In addition, the relative bioavailability of QUE-PC-SD was also higher than that of QUE-SD. Therefore, in regard to drugs with poor solubility and low permeation, an active constituent-PC-SD system could result to a better absorption and higher bioavailability. |
