正交法制备羧甲基壳聚糖－纳米银纳米微球

目的:制备以纳米银为模型药物的羧甲基壳聚糖载药纳米微球，探索载药纳米微球的制备条件对粒径、包封率的影响，确定最佳制备工艺。方法:三聚磷酸钠为交联剂，采用离子交联法制备载药纳米微球，测量药物的包封率及粒径。紫外分光光度法测定该制剂中纳米银释放情况。结果:通过正交实验设计，优化了制备工艺条件，其最佳条件是羧甲基壳聚糖浓度4.2 mg/mL，滴速为5 s/滴，纳米银投药量为20 mg（500 μL）。在此条件下进行实验，制备出的载药纳米微球的平均粒径为514.1 nm，多分散系数0.204，包封率61.67%。8 h内累计释放量达80%以上，方程拟合以一级动力学方程拟合效果最好。结论:该制备工艺简单、稳定，可制备出包封率高、粒径适宜的羧甲基壳聚糖-纳米银纳米微球。

Preparation of carboxymethyl chitosan-nano sliver nanoparticles by orthogonal design

Objective: To prepare carboxymethyl chitosan drug-loaded nanoparticles with nano silver as model drug the influence of the drug-loaded nanoparticles preparing conditions on the particle size and the encapsulation efficiency to select the optimum conditions for preparation. Methods:With sodium tripolyphosphate as crosslinking agent, Drug-loaded nanoparticles were prepared by ionic cross-Linking method. The drug encapsulation efficiency and particle size were measured. The release of nano-sliver from preparations byultraviolet spectrophotometry was observed. Results:Through the orthogonal design，preparation method was optimized. The optimum conditions included the carboxymethyl chitosan concentration of 4.2 mg/mL，speed of 5 s/drops，and the best dosage of nano sliver for 20 mg（500 μL）. In this experiment，the mean size of the preparation drug-loaded nanoparticles was 514.1 nm with the polydispersity index of 0.204，and the encapsulation efficiency was 61.67%.The accumulated amount of release in the preparations is more than 80% at 8 h.Equation of in vitro release model fitted best to Kinetic equation. Conclusion:This preparation method is simple and stable. The carboxymethyl chitosan-nano sliver nanoparticles can be prepared with a high encapsulation efficiency and suitable particle size.