阿维菌素/乙基纤维素载药纤维的制备及稳定性分析

【目的】在农林害虫防治过程中阿维菌素(AVM)因光解性易造成药效损失,为此开发阿维菌素/乙基纤维素(AVM/EC)载药纤维,以制备工艺简单、成本低廉的AVM抗光解剂型。【方法】以乙基纤维素(EC)为载体,甲醇为溶剂,按AVM与EC质量比(m_AVM:m_EC)分别为1:10、1:8、1:6、1:4、1:2,采用溶剂共混-加水析出的方法制备AVM/EC载药纤维,并测定了载药纤维产率、AVM利用率、载药量、光稳定性及热贮稳定性,同时对AVM/EC载药纤维进行X射线衍射(XRD)分析。【结果】通过溶剂共混-加水析出法,可将AVM以无定形状态均匀地负载到EC中; 当m_AVM:m_EC为1:10～1:6时,载药纤维产率大于91. 85%,AVM利用率大于81. 18%,紫外光照射12 h光解率小于15. 80%,(54±2)℃热贮14 d后,89. 14%以上AVM未降解。【结论】通过溶剂共混-加水析出的方法制备AVM/EC载药纤维,可以将AVM以无定形状态均匀负载到EC中,提高AVM光稳定性及热贮稳定性,这可为AVM剂型开发提供新思路。

Preparation and stability of avermectin-loaded ethylcellulose

【Objective】The photolysis of avermectin(AVM)always reduces the effectiveness of its application in agricultural and forest pest control. Here, a simple and economical method was used to improve its photostability.【Method】Ethylcellulose(EC)was employed as the carrier, while methanol was employed as the solvent for this process. AVM and EC were mixed in mass ratios(m_AVM:m_EC)of 1:10, 1:8, 1:6, 1:4, and 1:2 to prepare a series of solutions. Five times the volume of distilled water was then added to the solutions to precipitate the AVM-loaded EC(AVM/EC). The yield, drug-loading rate, photostability, and thermostability of AVM/EC, as well as the utilization rate of AVM, were then determined. Additionally, X-ray diffraction(XRD)analysis was performed to characterize the AVM/EC samples.【Result】The method achieved a shapeless and uniform dispersal of AVM in EC. When the m_AVM:m_EC was increased from 1:10 to 1:6, the AVM/EC yield exceeded 91.85%, while the AVM utilization rate was higher than 81.18%. Additionally, a photodegradation rate of under 15.80% was observed after ultraviolet light exposure for 12 h, and an AVM degradation less than 10.86% was observed. These results were obtained after the AVM/EC was kept at(54 ± 2)℃ for 14 days.【Conclusion】The solvent blending-water addition precipitation method yielded a homogeneous structure of AVM/EC that improved the photostability and thermostability of AVM. Therefore, this method could be a potential approach for the preparation of AVM for incorporation into dosage forms.