磁性壳聚糖微球的释药和靶向研究

Preparation of magnetic chitosan microspheres

目的:利用改变pH值法制备磁性壳聚糖微球,并对微球的载药量、缓释特性和磁靶向特性进行测试。方法:采用紫外光谱吸收法测定载药量,渗透袋扩散技术测试微球的释药速度,体外模拟法测定微球的磁靶向性。结果:载药量为37%,包封率62%。微球10h内药物释放约为75%,连续释放78h。外加磁场应在2000～3000Gs左右,施加时间在2h为宣。结论:使用改变pH值法制备的壳聚糖微球,具有较高的载药量和包封率,微球缓释效果明显,并实验测出了适合微球靶向控制的磁场施加方式。

Objective：To characterize magnetic chitosan microspheres newly prepared by using a pH adjustment. Methods： The loading dose of the chitosan microspheres were analyzed using ultraviolet spectrograph; the dissolution was determined using a filter-bag diffusion technique and the magnetic target test was conducted by a vitro-simulation technique. Results： The key parameters of the microspheres were as follows： loading capability of drugs 37%, entrapment efficiency 62%, the release rate 75% within 10 hours and the sustained release for 78 hours. The optimal magnetic condition was 2 000 - 3 000Gs for 2 hours. Conclusion： The optimal magnetic chitosan microspheres were achievable by adjusting pH value.