HPLC法测定甘草素的平衡溶解度和表观油水分配系数

目的:测定甘草素在不同溶剂中的平衡溶解度和表观油水分配系数,为甘草素的剂型设计提供依据。方法: 采用HPLC法测定甘草素在5种溶剂中的平衡溶解度及在正辛醇-缓冲液中的表观油水分配系数。结果: 37℃时甘草素在水中的平衡溶解度为69.29 μg·mL^-1,表观油水分配系数为21.94(lgP=1.34);在乙醇中溶解度最大,为116966.24 μg·mL^-1,油水分配系数在pH 5.8时最大,为37.23(lgP=1.57)。结论: 甘草素的水溶性较差,渗透性较好,可考虑应用增溶辅料或通过制剂技术增大溶解度,以提高生物利用度。

Objective: To determine the equilibrium solubility of liquiritigenin and its apparent oil/water partition coefficients in different solvents,so as to provide a basis for dosage form design. Methods: A high performance liquid chromatography (HPLC) was established to detect the equilibrium solubility of liquiritigenin in five solvents and the apparent partition coefficient for the n-octanol-water/buffer solution system. Results: The equilibrium solubility of liquiritigenin was 69.29 μg·mL^-1 in water at 37℃,the apparent oil/water partition coefficient was 21.94 (lgP=1.34),the maximum equilibrium solubility was 116966.24 μg·mL^-1 in ethanol,and the maximum of apparent partition coefficient was 37.23 (lgP=1.57) at pH 5.8. Conclusion: Liquiritigenin has a poor water-solubility and a good permeability.Therefore solubilizers and drug preparation can be considered to increase its equilibrium solubility in order to improve its bioavailability.