小檗碱聚乳酸微球的制备工艺及特性研究

采用溶剂挥发法制备小檗碱聚乳酸微球, 选择小檗碱与聚乳酸的投料比、二氯甲烷与水的体积比和乳化剂PVA的质量分数3个因素为实验因素，以包封率和载药量为优化指标, 采用L9(3⁴)正交试验优选最佳处方和制备工艺,测定微球的粒径分布、包封率,并进行体外释药试验。小檗碱聚乳酸微球的算术平均粒径为(53.0±3.5)μm(n=500),载药量为(8.96±0.3)%(n=3),药物包封率为(83.4±0.5)%(n=3)，37℃时30d内微球体外累积释药量为82.03%。小檗碱聚乳酸微球球形圆整,释放良好，分子量2.5万左右的聚乳酸较适宜制作微球。

Preparation and characteristics of berberine polylactic acid microspheres

Microspheres containing berberine and polylactic acid were prepared by an oil-in-water emulsifying solvent-evaporation process. The proportions of berberine and polylactic acid, dichloromethane and water, and concentration of PVA were taken as the three experimental factors in an L9(3⁴) orthogonal design in order to find the optimum conditions. The distribution of particle sizes, the encapsulation ratio and in vitro release rate were measured. The mean particle diameter was found to be (53.0±3.5) μm(n=500), the drug loading was (8.96±0.3)% (n=3), and the encapsulation efficiency was (83.4±0.5)% (n=3). The in vitro accumulated release rate of the microspheres was found to be 82.03% after 30 days at 37℃. These data indicate that PLA having molecular weight of 25000 is a suitable material for preparing berberine microspheres for controlled release. 