Shiga K, Muramatsu N, Kondo T
Faculty of Pharmaceutical Sciences, Science University of Tokyo, Shinjuku, Japan.
J Pharm Pharmacol. 1996 Sep;48(9):891-5. doi: 10.1111/j.2042-7158.1996.tb05995.x.
In an attempt to prepare monodisperse poly(D,L-lactide) and copoly(lactide-glycolide) microspheres, a novel emulsification technique (membrane emulsification) was employed and the preparation conditions which might affect the monodispersity were evaluated. With this technique nearly monodisperse poly(D,L-lactide) and copoly(lactide-glycolide) microspheres were successfully prepared and their sizes were controllable only by making use of microporous glass membranes of different pore sizes. However, in the present system of emulsion (methylene chloride/water) the surfactant used was limited to ionic ones and the amount of polymers available for the formation of microspheres was inevitably too small in concentration to entrap sufficient amounts of drug. As for the drug release, the effect of particle size was not appreciable but the method of solvent removal gave a great influence; the solvent extraction method showed a more drug-sustaining effect than did the solvent evaporation method. The present results suggest the possibility of making drug-loaded and biodegradable monodisperse microspheres.
为了制备单分散的聚（D，L-丙交酯）和聚（丙交酯-乙交酯）共聚物微球，采用了一种新型乳化技术（膜乳化），并评估了可能影响单分散性的制备条件。通过该技术成功制备了几乎单分散的聚（D，L-丙交酯）和聚（丙交酯-乙交酯）共聚物微球，并且仅通过使用不同孔径的微孔玻璃膜就可以控制它们的尺寸。然而，在目前的乳液体系（二氯甲烷/水）中，所用的表面活性剂仅限于离子型表面活性剂，并且可用于形成微球的聚合物浓度不可避免地过低，无法包封足够量的药物。至于药物释放，粒径的影响不明显，但溶剂去除方法有很大影响；溶剂萃取法比溶剂蒸发法显示出更强的药物缓释效果。目前的结果表明制备载药且可生物降解的单分散微球是有可能的。
