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[摘要]
目的 优化积雪草总苷(CTG)脂质体的制备工艺,并考察其体外透皮特性规律。方法 采用逆相蒸发法,以羟基积雪草苷、积雪草苷的包封率为评价指标,通过单因素考察结合Box-Behnken效应面法优化CTG脂质体的制备工艺,并对其表面特征、包封率、粒径、Zeta电位、体外释放度及体外透皮性能进行考察。结果 最佳处方为卵磷脂-胆固醇的质量比4∶1,卵磷脂-CTG的质量比23.22∶1,有机相-水相的体积比7∶1。所得脂质体形态呈球型,表面圆整、无粘连;平均粒径201.7 nm;Zeta电位-15.7 mV;羟基积雪草苷、积雪草苷的平均包封率为75.85%、84.94%;羟基积雪草苷、积雪草苷体外12 h累积释放率分别为52.10%、45.97%;脂质体中羟基积雪草苷、积雪草苷的透皮速率拟合方程分别为Q=67.93t1/2-50.34,R2=0.988,Q=139.74 t1/2-241.2,R2=0.987;皮肤滞留量分别为76.0、48.7 μg/cm2,相对原料药溶液提高到1.56和1.18倍。结论 优选的制备工艺合理可行、稳定性好,所得CTG脂质体包封率高、粒径小、皮肤滞留量大、缓释作用明显。
[Key word]
[Abstract]
Objective To optimize the preparation technology for Centella asiatica total glucosides (CTG) liposome and to investigate its percutaneous permeability in vitro.Methods Liposomes were prepared by reverse-phase evaporation technique.Taking the entrapment efficiency of madecassoside and asiaticoside as indexes, the preparation of liposome was optimized by using single factor and Box-Behnken response surface method.The properties of liposomes including morphology, entrapment efficiency, mean diameter, Zeta potential, and accumulative release were studied.Results The optimal formulation was lecithin-cholesterol (4:1), lecithin-CTG (23.22:1), and organic-aqueous (7:1).The liposome was smooth and spherieal in appearance, mean diameter, and Zeta potential were 201.7 nm and-15.7 mV, respectively.The entrapment efficiency of madecassoside and asiaticoside were 75.85% and 84.94%.The in vitro 12 h accumulative release was 52.10% and 45.97%.The equations for the permeation rate of madecassoside and asiaticoside in liposomes were Q=67.93 t1/2-50.34, R2=0.988, Q=139.74 t1/2-241.2, R2=0.987, respectively.The retention amount in the skin was 76 μg/cm2 and 48.7 μg/cm2, which were 1.56 and 1.18 times higher than those of solution.Conclusion The optimized process is rational, feasible, and good stability.The CTG liposome prepared in this study have the smaller size, the higher encapsulation efficiency, higher retain in skin and obvious sustained-release effects.
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[基金项目]
重庆市科委应用开发重大项目(cstc2014yykfC10006)