半纤维素基阿维菌素载药微囊的制备及性能

目前阿维菌素以高效性、无污染和低抗药性等特点而得到广泛应用，但是其稳定性较差，易降解导致使用量较大从而造成浪费。为解决上述问题，本文以半纤维素为基体，利用原位聚合法制备阿维菌素载药微囊（HDCM），通过制备条件、热降解性、储存稳定性和释放动力学研究，确定了HDCM的载药量、热稳定性及释放性能。结果表明，在芯壁比为1∶34（质量比），温度为65℃，pH为3.5的制备条件下，HDCM的载药量可达66.5%，粒径较小且分散均匀。HDCM的热降解性能和恒温热稳定性能较阿维菌素原药有所提高，最高热分解温度从261℃增加到272℃，阿维菌素原药10h后降解率达到12.1%，而载药量为66.5%的HDCM降解率仅为5.2%。HDCM的释放机理满足Fick扩散，阿维菌素原药在水中的累积释放率在12h之内达到83.8%，而HDCM的累积释放率在24h之后才有所增大，12h内其释放率仅为33.7%，表明HDCM具有极好的缓释性能。

Study on preparation and properties of hemicellulose abamectin-loaded microcapsule

Abamectin has been widely used due to its high efficiency, pollution-free, and less drug resistance, but its poor stability and easy degradation lead to a large amount of utilization and waste. To solve the problems, abamectin-loaded microcapsule (HDCM) based on hemicellulose was prepared by in-situ polymerization. By studying preparation conditions, thermal degradation, storage stability and release kinetics, drug loading, thermal stability and release performances of HDCM were determined. The results showed that the drug loading of HDCM could reach 66.5%, and it had small particle size and uniform dispersion under the preparation conditions of the core-wall mass ratio of 1∶34, temperature of 65℃ and pH of 3.5. The thermal degradation performance and constant temperature thermal stability of HDCM were improved compared to avermectin agent. The maximum temperature of thermal decomposition was increased from 261℃ to 272℃. After 10h, the degradation rate of avermectin agent reached 12.1%, and the degradation rate of HDCM with the drug loading of 66.5% was only 5.2%. The release mechanism on HDCM satisfies Fick diffusion. The cumulative release rate of avermectin agent in water reached 83.8% within 12h, while the cumulative release rate of HDCM gradually increased after 24h. Within 12h the release rate of HDCM was only 33.7%, indicating that HDCM had excellent sustained release performance.