吡丙醚乙基纤维素微胶囊的制备及其性能研究

Preparation and Characterization of Pyriproxyfen-Ethyl Cellulose Microcapsule

[目的]针对杀蚊剂吡丙醚传统剂型持效期短的问题,以生物可降解材料乙基纤维素为壁材制备吡丙醚微胶囊。[方法]采用溶剂挥发法制备吡丙醚微胶囊,并进行工艺优化,其结构经扫描电子显微镜、傅立叶变换红外光谱仪、X射线粉末衍射仪进行表征,用液相色谱测其包封率、载药量和释放性能,最后采用幼虫浸液法测试吡丙醚微胶囊对白纹伊蚊幼虫的致死效果。[结果]乙基纤维素和吡丙醚质量分数为2%、芯壁比为1∶1、明胶质量分数为4%、油水两相体积比为1∶4时,制备的微胶囊外观呈规则球形,粒径适中(27.80μm),载药率为40%;体外释放试验表明,吡丙醚微胶囊144 h累计释放率为59.3%,符合Ritger Peppas释放机理-非Fick扩散;吡丙醚微胶囊72 h对白纹伊蚊幼虫的致死率为96.7%,180 d的24 h死亡率为95%,远高于商品化制剂5%吡丙醚水乳剂。[结论]制备的吡丙醚微胶囊速杀效果好、持效时间长,具有一定的经济价值与实际应用前景。

[Aims]This study aims to improve the duration of pyriproxyfen,the preparation technology of its microcapsule by solvent evaporation method was explored.[Methods]The pyriproxyfen ethyl cellulose microcapsules were prepared by solvent volatilization method,and the process was optimized.The microcapsules were characterized by scanning electron microscopy,Fourier transform infrared spectroscopy,and X-ray powder diffractometer.The encapsulation efficiency,drug loading and release performance were measured by liquid chromatography.Finally,the dip method was used to test the lethal effect of pyriproxyfen microcapsules on the larvae of Aedes albopictus.[Results]The mass fraction of ethyl cellulose and pyriproxyfen is 2%,the core-wall ratio is 1:1,the mass fraction of gelatin is 4%,and the volume ratio of oil and water phases is 1:4.The prepared microcapsules have a regular spherical appearance which has a moderate particle size of 27.80μm and a drug loading rate of 40%.The in vitro release test showed that the cumulative release rate of pyriproxyfen microcapsules during 144 hours was 59.3%,which was in line with the Ritger Peppas release mechanism non-Fick diffusion.The biological activity test showed that the lethality of pyriproxyfen microcapsules against A.albopictus larvae at 72 h was 96.7%,and the 24-hour mortality rate was 95%in 180 days,which was much higher than the commercial formulation of pyriproxyfen 5%EW.[Conclusions]The prepared pyriproxyfen microcapsules have good quick killing effect and long lasting effect,and have certain economic value and practical application prospects.