毒死蜱/乙基纤维素微胶囊的制备及其缓释性能

摘要

以乙基纤维素为壁材、毒死蜱为模型药物,采用乳化-溶剂挥发法制备毒死蜱/乙基纤维素微胶囊.利用FTIR、SEM和DSC表征了微胶囊的结构和形貌以及毒死蜱的分布形态,运用单因素法考察芯材比、聚乙烯醇(PVA)质量分数、PVA与十二烷基硫酸钠(SDS)质量比和搅拌速度对微胶囊的载药量和包封率的影响,并探究芯材比和PVA质量分数对微胶囊的药物释放性能的影响.结果表明,毒死蜱/乙基纤维素微胶囊具有较为致密的球形结构,而毒死蜱以结晶态分布于微胶囊中.当芯材比为2:3、PVA质量分数为1.5%、PVA与SDS质量比为3:2和转速为1500r/min,其载药量和包封率相对较好,分别为44.41%和82.42%.该载药微胶囊具有良好的缓释性能,其释药行为可用Korsmeyer-Peppas动力学模型来描述,且药物释放受Fickian扩散控制.%Chlorpyrifos/ethyl cellulose microcapsules were prepared by mulsification-solvent evaporation method with the ethyl cellulose as wall material and the chlorpyrifos as model drug. The structures and morphologies of microcapsules,form of chlorpyrifos were characterized by FTIR,SEM and DSC. The effect of core material ratio,PVA concentration,PVA to SDS mass ratio and stirring speed on loading content(LC) and encapsulation efficiency(EE)werestudied using single factor method. Besides,the effects of core material ratio and PVA concentration on sustained release of chlorpyrifos were also discussed. The results showed that chlorpyrifos/ethyl cellulose microcapsules had a more condensed spherical structure,and the crystalline chlorpyrifos was distributed in microcapsules. When the core material ratio was 2:3,PVA concentration was 1.5%,the mass ratio of PVA:SDS was 3:2 and stirring speed was 1500 r/min,the LC and EE were better,which were 44.41% and 82.42%,respectively. Meanwhile,the microcapsules had good sustained release properties,and their releasing curves could be described by Korsmeyer-Peppas equation indicating that the drug release was controlled by Fick diffusion.