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以聚乳酸-羟基乙酸(PLGA)为载体材料,牛血清蛋白(BSA)为蛋白模型药物,采用复相乳化溶剂法制备PLGA载药微球,探索载药微球制备过程中囊芯比、初乳水油比、分散剂浓度、超声乳化时间对微球粒径大小、载药率、包封率的影响。结果表明,最优载药微球的制备条件为:囊芯比1∶1,初乳水油比3∶5,分散剂质量分数0.5%,超声乳化时间2 min。在此条件下,所得PLGA微球的粒径为268.7 nm,载药率30.88%,包封率46.95%;电镜照片表明微球表面连续光滑,粒径分布较均匀。采用静电吸附法用阳离子聚电解质壳聚糖对最佳条件下的PLGA载药微球进行表面修饰,扫描电镜表明复合后微球粒径变大,能谱分析表明复合后微球中有N元素存在,即复合微球中存在壳聚糖,电荷测试表明微球表面带正电;体外释放实验表明PLGA-CS复合载药微球的缓释时间延长,释药初期的突释性明显改善。
Polylactide-glycolic acid (PLGA) was used as carrier material, and bovine serum albumin (BSA) was used as drug model drug. PLGA drug-loaded microspheres were prepared by double phase emulsification solvent method. Water to oil ratio, dispersant concentration, ultrasonic emulsification time on the microsphere size, drug loading rate, encapsulation efficiency. The results showed that the preparation conditions of the optimal microspheres were as follows: ratio of vesicle to core 1: 1, ratio of water to oil in colostrum 3: 5, mass fraction of dispersant 0.5% and emulsification time 2 min. Under these conditions, the particle size of the obtained PLGA microspheres was 268.7 nm, the drug loading rate was 30.88% and the entrapment efficiency was 46.95%. Electron microscopy images showed that the surface of the microspheres was continuous and smooth and the particle size distribution was more uniform. Electrostatic adsorption method using cationic polyelectrolytes chitosan PLGA microspheres under the best conditions for surface modification, scanning electron microscopy showed that the composite microspheres became larger particle size, energy spectrum analysis showed that composite microspheres N element The presence of chitosan in the composite microspheres, the charge test showed that the surface of the microspheres are positively charged; in vitro release experiments showed that PLGA-CS composite loaded microspheres extended release time, release early significantly improved.