左旋十八甲基炔诺酮新型避孕微胶囊的研制及其药物动力学的评价

本研究用乙交酯丙交酯共聚物（ＰＬＧＡ）为囊材，以左旋十八甲基炔诺酮（ＬＮＧ）为主药，用新工艺合成了几种新型ＬＮＧ微胶囊，并对它们进行了扫描电镜观察、体外释放度及动物（兔）体内释药动力学实验。结果发现，新型ＬＮＧ微胶囊由于其含有一个不含药物的控释层，改变了原来的释药模式，在爆破释放峰后都出现了一个第二释放峰，且这种第二释放峰出现的时相取决于新型微胶囊的粒径即控释层的厚度，它为筛选和控制药物的周期性释放提供了新的模式，展现了广阔前景。

Preparation and Pharmacokinetic Evaluation of A New Injectable Microcapsule of Levonorgestrel

A new long-acting formulation of injectable microcapsules made of biodegradable copolymer of glycolide has been achieved by the modification of the surface properties of the prototype formulation.The results of tests in vitro and in vivo in rabbits have shown that there is prominent second peak in the release curve of the new LNG microcapsules,and the time phase of the second peak release depends on the size of the new LNG microcapsules.The properties of the new microcapsules have been discussed.