苦杏仁苷脂质体的制备及特性研究

Preparation of amygdalin-loaded liposomes and the characteristics study

为提高苦杏仁苷的脂溶性、稳定性、生物利用率以及缓释效果,利用逆向蒸发法制备苦杏仁苷脂质体,通过单因素和正交试验对制备工艺条件进行优化,并研究其物化性质、储藏稳定性和体外释放特性。得到苦杏仁苷脂质体的最优制备工艺条件:磷脂和胆固醇质量比为4∶1、有机相与水相体积比为2∶1、磷酸盐缓冲液pH值为6.6、苦杏仁苷与磷脂质量比为5%,此条件下脂质体的包封率为(33.42±1.76)%。苦杏仁苷脂质体平均粒径为(189.7±1.3)nm,多相分散指数为0.16±0.02,zeta电位为(-31.20±2.41)mV。通过透射电子显微镜观察到苦杏仁苷脂质体囊泡呈规则的球体,分布均匀。稳定性试验结果表明:苦杏仁苷脂质体具有较好的储藏稳定性,特别是在低温条件下可以有效抑制苦杏仁苷渗漏、囊泡聚集、融合以及膜氧化。体外释放试验结果表明:脂质体包埋后可有效降低苦杏仁苷的释放速率,具有良好的缓释特性。

To improve the lipid solubility,stability,bioavailability and slow-release effect of amygdalin,amygdalin-loaded liposomes were prepared by reverse evaporation method.Based on single factor and orthogonal experiments,the preparation conditions were optimized.The physicochemical properties,storage stability,and in vitro release characteristics of the liposomes were also studied.The optimum conditions for preparing amygdalin-loaded liposomes were as follows:the mass ratio of phospholipids to cholesterol was 4∶1,the volume ratio of organic phase to water phase was 2∶1,pH value of phosphate buffer solution was 6.6,and the mass ratio of amygdalin to phospholipids was 5%.Under the optimum conditions,the encapsulation efficiency of amygdalin-loaded liposomes was(33.42±1.76)%.The average vesicle size of amygdalin-loaded liposomes was(189.7±1.3)nm with the polydispersity index of 0.16±0.02,and the zeta potential was(-31.20±2.41)mV.The morphology of amygdalin-loaded liposomes was observed by transmission electron microscope.It showed that amygdalin-loaded liposomes vesicles were spherical and distributed uniformly.In addition,the results indicated that amygdalin-loaded liposomes were relatively stable during the storage period and could effectively inhibit the leakage,aggregations,and membrane oxidation of amygdalin especially at low temperature.This study also suggested that the release rate of amygdalin could be reduced by encapsulating with liposomes thereby achieving better slow-release characteristics.