水溶性甘草次酸冻干粉的制备及理化分析

Preparation and physicochemical analysis of water-soluble glycyrrhetinic acid freeze-dried powder

目的:制备水溶性甘草次酸冻干粉,并进行理化分析。方法:将甘草次酸溶解于三氯甲烷和乙醇的混合溶剂作为油相,甘露醇溶解于三氯甲烷饱和水溶液作为水相,使用高速匀浆器进行乳化形成油包水型(o/w)粗乳,接着转入高压均质机内乳化得到亚微乳。再利用真空旋转蒸发除去有机溶剂,经冷冻干燥获得水溶性甘草次酸冻干粉。形成粗乳的第一步乳化工艺借助单因素法进行优化。结果:甘草次酸粗乳的最佳制备工艺条件是油相和水相体积比为15%,甘草次酸浓度为155 mg·mL^(-1),乳化次数为18次;水溶性甘草次酸冻干粉在水中分散良好呈现乳光,没有肉眼可见颗粒;其平均粒径为241.1 nm,扫描电镜下观察呈规则棒状;在37℃水中溶解度为23.08μg·mL^(-1),比甘草次酸原粉(3.84μg·mL^(-1))提高了大约5倍。结论:乳化法能将甘草次酸粒径减小至纳米范畴,并且提高其水中溶解度。

Objective：To prepare and conduct physicochemical analysis of water-soluble glycyrrhetinic acid freeze-dried powder.Methods：Glycyrrhetinic acid was dissolved in the mixed solvent with chloroform and ethanol,which was used as oil phase.Meanwhile,mannitol was dissolved in water saturated by chloroform,which was used as water phase.High speed homogenizer was utilized to prepare crude emulsion.Next,high pressure homogenization technique was employed to treat the crude emulsion to obtain submicron emulsion.The residual organic solvent was eliminated through vacuum rotary evaporation.Finally,water soluble glycyrrhetinic acid freeze-dried powder was obtained by lyophilization.The emulsification technology used to prepare crude emulsion was optimized by single factor method.Results：The optimized conditions were the volume ratio of oil phase and water phase（15%）,glycyrrhetinic acid concentration（155 mg·mL（-1））,emulsification times（18）.The water-soluble glycyrrhetinic acid freeze-dried powder was dispersed well in water and opalescent and there was no visible particles;its mean particle size was 241.1 nm with regular rod-like structure observed through scanning electron microscope;the water solubility of water-soluble glycyrrhetinic acid freeze-dried powder at 37 ℃ was 23.08 μg·mL（-1）,which increased about 5 times compared with glycyrrhetinic acid（3.84 μg·mL（-1））.Conclusion：The particle size of glycyrrhetinic acid can be reduced to nanometer scale by emulsification method and the water solubility of glycyrrhetinic acid can be improved.