伊维菌素微胶囊的制备及其体外释放的研究

Studies on Preparation and Stability of Iverm ectin Microcapsules

关键词:  伊维菌素,单凝聚法,微胶囊,缓释,油混悬剂

Key words:  ivermectin,single  coagulation, microcapsules,sustained  released

摘要:

市售伊维菌素制剂存在生物利用度低，释药峰谷浓度差异大等问题，本文以明胶为囊材，采用单凝聚法制备伊维菌素长效注射微胶囊油混悬剂。以微胶囊的粒径、载药量和包封率为制备工艺的优化指标，采用分光光度法测定微胶囊内药物含量及包封率。结果显示：最佳工艺制备的微胶囊的平均包封率为63.2%，载药量为18.3%，微胶囊的正圆度高、表面平滑，粒径分布在20~50 μm，药物呈缓慢持续释放，体外累计释放率18 h为30.0%，44 h后仅为51.0%。伊维菌素微胶囊制剂可大大增加体内留存时间，提高生物利用度，缓释效果显著。

Abstract:

There were problems as low bioavailability and large difference of drug release concentration between peak-valley in commercially available ivermectin (IVM) preparations. Gelatin was used to make microcapsules of IVM long–acting oil suspension by single-coagulation method. The particle size of microcapsules under microscope was examined and the medicine concentration and encapsulation efficiency of microcapsules were determined by UV spectrophotometry method. The encapsulation efficiency of IVM microcapsules obtained by the method was 63.2% and drug loading was18.3%. The particle size distribution was between 25 μm and 50 μm. The total released drug rate reached to 30.0% at 18h and 51.0% at 44h in vitro test. IVM was sustained release after then, which was consistent with our aim to keep the microcapsule releasing slowly and persistently.