Leelarasamee N, Howard S A, Malanga C J, Ma J K
School of Pharmacy, West Virginia University, Morgantown 26506.
J Microencapsul. 1988 Apr-Jun;5(2):147-57. doi: 10.3109/02652048809056478.
A solvent partition technique for the microencapsulation of hydrocortisone-polylactic acid has been developed for the preparation of microcapsules of controlled particle size distribution and drug loading. The method involves continuous injection of a drug-polymer solution with a syringe infusion pump into flowing mineral oil where microcapsules are formed as the solvent of the drug-polymer is partitioned into the mineral oil. Using preselected syringe needle size and mechanical control of the mineral oil flow rate at the needle tip, microcapsules of consistent particle sizes and desired drug loadings were prepared. Microcapsules of different internal structures were also prepared by varying the solvent system for the drug-polymer preparation. Dissolution studies showed that at the same drug loading, the rate of the percentage drug release increased with decreasing particle size, and that at similar particle size distributions, the rate increased with increasing drug loading. These results indicate that both the particle size distribution, and the drug loading must be controlled in a microencapsulation process to produce microcapsules of controlled drug release rate.
已开发出一种用于氢化可的松-聚乳酸微囊化的溶剂分配技术，以制备具有可控粒径分布和药物载量的微胶囊。该方法包括用注射器输液泵将药物-聚合物溶液连续注入流动的矿物油中，在此过程中，药物-聚合物的溶剂被分配到矿物油中从而形成微胶囊。通过预先选择注射器针头尺寸并机械控制针尖处矿物油的流速，制备出了粒径一致且药物载量符合要求的微胶囊。还通过改变用于制备药物-聚合物的溶剂系统制备了不同内部结构的微胶囊。溶出度研究表明，在相同药物载量下，药物释放百分比速率随粒径减小而增加，并且在相似粒径分布下，速率随药物载量增加而增加。这些结果表明，在微囊化过程中必须同时控制粒径分布和药物载量，以制备出药物释放速率可控的微胶囊。
