阿维菌素缓释纳米粒子的制备及其性能研究

以β-环糊精为载体，用共沉淀法制备了阿维菌素缓释纳米粒子，并对其制备工艺、缓释性能和防紫外光降解作用进行了研究。结果表明，所制备的纳米粒子外观呈球状，平均粒径在50～120nm之间，β-环糊精对阿维菌素具有良好的包合作用，包合率最高可达65.82%；阿维菌素缓释纳米粒子与其原药相比缓释效果明显，并具有良好的防紫外光降解的作用，在300min内与原药相比降解缓慢。纳米粒子在96h后才释放出94.20%的阿维菌素，其累积释放动力学方程为Ra=-88.4348e^-0.1031t+86.0599，符合一级动力学释放模型。

Preparation and properties of nanoparticles for controlled release of avermectin

Nanoparticles for controlled release of avermectin have been prepared using β-cyclodextrin as a carrier by a co-precipitation method.The preparation process,release and UV-shielding properties of avermectin-loaded nanoparticles were also investigated.The nanoparticles had a spherical appearance with a diameter of 50-120 nm.The highest inclusion efficiency obtained was 65.82%.The controlled release properties of the nanoparticles were clearly demonstrated: 98.04% of avermectin was released from a dialysis bag containing free avermectin after 18 hours,whereas after 96 hours,only 94.20% of avermectin was released from a dialysis bag containing the nanoparticles.The UV-shielding properties of the nanoparticles also had a beneficial effect on the stability of avermectin.In 300 minutes,free avermectin itself decomposed completely under UV light,while avermectin incorporated in the nanoparticles decomposed more slowly.The accumulative release corresponded to a zero-order kinetics model,with the kinetic equation being Ra=-88.4348e-0.1032t+86.0599.