阿司匹林缓释微球的制备及其体外释药性能研究

Preparation of Aspirin Sustained-release Microspheres and Their Release Properties in vitro

目的:制备阿司匹林缓释微球,并考察其体外释药性能。方法:采用改良的乳化溶剂挥发法,以聚乳酸-羟基乙酸共聚物(PLGA)为载体材料、载药量和包封率为指标,固定PLGA为100 mg正交设计试验优化阿司匹林缓释微球的阿司匹林用量、外水相体积、丙酮-二氯甲烷体积比和聚乙烯醇(PVA)浓度,对最优处方所制微球进行验证和体外释放度考察。倒置显微镜和电子显微镜下观察微球表面形态,激光粒度分析仪考察微球粒径。结果:PLGA为100 mg时的最优处方:阿司匹林用量为20 mg、外水相体积为150 ml、丙酮-二氯甲烷体积比为1∶1、PVA浓度为1 mg/100 ml;所制微球的平均粒径为139.95μm,电镜下微球表面光滑圆整,载药量为8.6%,包封率为33%,240 h体外累积释放度为85.56%。结论:成功制得具有明显缓释作用的阿司匹林缓释微球。

OBJECTIVE： To prepare Aspirin sustained-release microspheres, and to investigate its release properties in vitro. METHODS： Modified emulsion-evaporation method was adopted. Using PLGA as carrier, with drug-loading amount and entrap- ment efficiency as index, setting PLGA as 100 mg, the preparation technology of Aspirin sustained-release microspheres was optimized by orthogonal test in respect of the amount of aspirin, water phase-oil phase proportion, ratio of acetone volume to dichloromethane volume and PVA concentration. The microspheres prepared by optimal prescription were validated and investigated in drug release in vitro. The appearance of the microspheres was observed by inverted microscope and electron microscope, and the particle size was investigated by laser particle size analyzer. RESULTS： When the amount of PLGA was 100 rag, the optimal formulation was as follows： the amount of aspirin 20 mg, water phase-oil phase proportion 1 ： 50, ratio of acetone volume to dichloromethane volume 1 ： 1, PVA concentration of 1 mg/100 ml. Average particle size was 139.95 μm, and the microspheres was smooth in appearance and round in shape. Other parameters were drug-loading amount of 8.6%, entrapment efficiency of 33%, 240 h accumulative release rate of 85.56%. CONCLUSIONS： Aspirin sustained-release microspheres with obvious sustained-release property are prepared successfully.