Controlled-release of leuprolide acetate from polylactic acid or copoly(lactic/glycolic) acid microcapsules: influence of molecular weight and copolymer ratio of polymer.
Controlled-release of leuprolide acetate from polylactic acid or copoly(lactic/glycolic) acid microcapsules: influence of molecular weight and copolymer ratio of polymer.
复制标题
聚乳酸或共聚（乳酸/乙醇）酸微胶囊中醋酸亮丙瑞林的控释：聚合物分子量和共聚比例的影响。
DOI：
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发表时间：
1988
影响因子：
1.7
通讯作者：
T. Shimamoto
中科院分区：
文献类型：
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作者：
Y. Ogawa;Masaki Yamamoto;Shigeyuki Takada;H. Okada;T. Shimamoto
采用水内干燥法制备了含有醋酸leuprolide的聚乳酸（PLA）或共聚（乳酸/乙醇酸）酸（PLGA）微胶囊，并考察了其体外释放规律。平均分子量为22500的聚乳酸制备的微胶囊和平均分子量为21200、共聚物比为75/25（乳酸与乙醇酸的摩尔比）的聚乳酸制备的微胶囊的释放率极小。用平均分子量为6000的聚乳酸制备的微胶囊，其释放速度相对较快，但在一个月内仍不能达到预期的药物水平。将几种水溶性化合物掺入平均分子量为22500的聚乳酸制备的微胶囊中，试图通过创建水通道来提高释放速度。这些化合物仅诱导高初始释放，而不能增加药物释放。以平均分子量为14000、共聚物比为75/25的PLGA制备的微胶囊的释药效果较理想，释药时间为一个月。观察到一个小的初始释放，随后持续35d的稳定释放，近似于零级动力学。
Polylactic acid (PLA) or copoly(lactic/glycolic) acid (PLGA) microcapsules containing leuprolide acetate were prepared by an in-water drying process and the release patterns were examined in vitro. The release rates were extremely small from microcapsules prepared with PLA of average molecular weight 22500, and from microcapsules prepared with PLGA having average molecular weight 21200 and a copolymer ratio of 75/25 (molar ratio of lactic acid to glycolic acid). The release rate of leuprolide acetate from the microcapsules prepared with PLA of average molecular weight 6000 was relatively fast, but was still too slow to give the desired drug level over one month. Several water-soluble compounds were incorporated into microcapsules prepared with PLA of average molecular weight 22500, in an attempt to increase the release rate by the creation of aqueous channels. These compounds only induced a high initial release and failed to increase drug release. The release profile of the drug from microcapsules prepared with PLGA of average molecular weight 14000 and a copolymer ratio of 75/25 was ideal for one month's release. A small initial release was observed followed by a steady release which lasted for 35d, and approximately followed zero-order kinetics.