硝苯地平聚乳酸缓释微球的制备

The Preparation of Nifedipine/PLA Microspheres

采用溶剂蒸发法,以聚乳酸为载体、二氯甲烷为溶剂、聚乙烯醇为分散剂制备了具有缓释功能的硝苯地平微球。研究结果表明微球粒径随搅拌速度的提高而减小;当聚乳酸用量一定时,溶剂体积增大,微球的粒径减小。扫描电子显微镜观察微球的外观为一光滑的圆球,平均粒径为18.9μm。释放研究表明载药微球具有控释功能,释放时间长达50h。

Polylactic acid （ PLA）microspheres （MS） were prepared by the emulsion-solventext reaction method. The nifedipine used as a drug and the methylene chloride was chosen as a good solvent for PLA to prepare microspheres .The evolution of the mean diameter and the extent of the size distribution of microspheres as a function of different preparation parameters were studied. The mean particle diameter decreased when the stirring rate increased. The dispersed state of nifedipine in the matrix is mostly influenced by the ratio of NFD to PLA. The NFD polylactic acid microspheres observed by scanning electron microscope, was regular in its morphology . The average particle size was 18.9μ m. Release of NFD from microspheres is sustained. The sustained release time lasted for 50 hours.