阿司匹林微胶囊的制备及其体外释放行为的研究

近年来,微胶囊技术在生物医药、化工、食品等行业得到了广泛应用和发展.以液中干燥法制备阿司匹林微胶囊,研究了微胶囊的形成过程、表观形貌、粒度及其体外释放行为.研究结果表明,阿司匹林微胶囊形成过程中,乙基纤维素分散成球,继而在各微球表面析出,微球越来越细密,表面空洞减小,最终形成完整的微胶囊.微胶囊表面致密、光滑,有少量细小的孔洞,多数呈球形,但粒度不均匀,有不规则杂片存在.粒度基本呈正态分布,平均粒径为1 445 nm.随着制备微胶囊过程中阿司匹林原料药加入量的增加,微胶囊成品的实际载药量增加,但其包覆率却随之减小.在体外释放初始阶段,微胶囊中阿司匹林的释放较快,继而释放速率减慢呈缓慢上升趋势.加入少量药品制备的微胶囊中阿司匹林释放速度较大.

Preparation and release behavior in vitro of aspirin microcapsule

In recent years,microcapsule techniques are applied and developed in biological medicine,chemical industry,food and other industries.In this study,aspirin microcapsules are prepared by solvent diffusion and evaporation method.The formation process,apparent morphology,particle size of microcapsule and it’s release behavior in vitro are researched.The results show that,in the formation process of aspirin microcapsule,ethyl cellulose are scattered into the balls,and then precipitated on the surface of micro ball.Meanwhile,the balls become denser.The cavities on the surface are shrinked,and the complete microcapsules are finally formed.The surface of microcapsule is compact and smooth.There are a little tiny holes.Most of microcapsule are sphere,however the particles size is nonuniform.there are irregular pieces in it.The particle size shows normal distribution.The average particle size is 1 445 nm.With the dose of aspirin increasing in the preparation process,the actual drug-loading rate of aspirin microcapsules increases,yet the encapsulation rate decreases.In the initial stage release process in vitro,the release speed of aspirin is fast at first,and then exhibts a slow rise trend.The release rate of microcapsule is larger with little aspirin preparation.