Zhang Yu, Zhang Yun
Institute of Materia Medica, He'nan University, Kaifeng 475004, China.
Zhongguo Zhong Yao Za Zhi. 2012 Feb;37(4):466-70.
To prepare kappa-carrageenan-chitosan polyelectrolyte gel pellets and detect the effects of formulation and preparation factors on in vitro drug release from the pellets.
The K-carrageenan-chitosan polyelectrolyte gel pellets with baicalin as model drug were prepared by ionotropic gelation technique. The ratio of kappa-carrageenan/chitosan in pellets was determined with the composite of K-carrageenan and chitosan. The effects of the concentration of K-carrageenan, the ratio of drug/kappa-carrageenan, the concentration of gelling solution, gelling time and drying method on the release of pellets were determined by in vitro drug release.
The mass ratio of K-carrageenan/chitosan in pellets was 6: 4. Release of the pellets in 0.1 mol x L(-1) HCl was about 10% for 2 hours and fast in PBS, indicating a typical sustained release property. The pellets released less with the increase in the concentration of K-carrageenan, the ratio of drug/kappa-carrageenan and the concentration of KCl. They also released less with the increase in gelling time, but showed little effect until 1 hour. The release of the pellets prepared by the freeze-drying method was much faster than those by vacuum drying and atmospheric drying methods which had little influence on drug release.
The K-carrageenan-chitosan polyelectrolyte gel pellets had sustained release property. Their drug release rate could be regulated with different formulation and preparation factors.
制备κ-卡拉胶-壳聚糖聚电解质凝胶微丸，并考察处方及制备因素对微丸体外释药的影响。
以黄芩苷为模型药物，采用离子凝胶法制备κ-卡拉胶-壳聚糖聚电解质凝胶微丸。通过κ-卡拉胶与壳聚糖的复合物测定微丸中κ-卡拉胶/壳聚糖的比例。采用体外释药法考察κ-卡拉胶浓度、药物/κ-卡拉胶比例、胶凝液浓度、胶凝时间及干燥方法对微丸释药的影响。
微丸中κ-卡拉胶/壳聚糖的质量比为6∶4。微丸在0.1 mol·L-1 HCl中2 h的释放率约为10%，在PBS中释药较快，呈现典型的缓释特性。随着κ-卡拉胶浓度、药物/κ-卡拉胶比例及KCl浓度的增加，微丸释药量减少。随着胶凝时间的延长，微丸释药量也减少，但在1 h内影响较小。冷冻干燥法制备的微丸释药速度比真空干燥法和常压干燥法快得多，后两种干燥方法对药物释放影响较小。
κ-卡拉胶-壳聚糖聚电解质凝胶微丸具有缓释特性，其释药速率可通过不同的处方及制备因素进行调节。
