pH敏感型羧甲基壳聚糖水凝胶的制备及体外释药考察

目的:研制一种新型羧甲基壳聚糖基pH敏感性水凝胶,考察其在药物传输体系中的应用.方法:采用钙离子交联方法制备有良好pH响应性能的羧甲基壳聚糖基水凝胶,并对其pH响应性能进行相关的表征.以磺胺嘧啶钠为模型药物,考察载药水凝胶在不同pH环境条件下(pH =2和pH =7.4)的药物释放行为.结果:所制备的羧甲基壳聚糖水凝胶具有明显的孔洞结构和良好的pH响应性能,在中性磷酸盐缓冲溶液(pH=7.4)中吸水率显著大于在酸性溶液(pH=2)中的吸水率.载有磺胺嘧啶钠的羧甲基壳聚糖水凝胶在中性磷酸盐缓冲溶液(pH=7.4)中的4h的药物累计释放率达到95％,而在酸性溶液(pH=2)中的4h的药物累计释放率却只有50％.结论:本文所制备的羧甲基壳聚糖pH敏感性水凝胶具有良好的孔隙率和pH响应性能,在口服药物传输体系中有一定的应用前景.

Preparation and in vitro Drug Release of Carboxymethyl Chitosan pH-sensitive Hydrogels

ABSTRACT Objective: To develop a novel carboxymethyl chitosan pH sensitive hydrogels for the potential application in the drug delivery systems. Method:The pH sensitive carboxymethyl chitosan hydrogels were prepared by a calcium cross linking method and characterized. Sulfadiazine sodium was selected as the model drug to evaluate the drug release behavior of the hydrogels in various pH conditions (pH=2 and pH=7.4). Result:The developed carboxymethyl chitosan hydrogels showed significant porosity and pH sensitivity, and the water absorption of the hydrogels in the PBS solution (pH=7.4) was significantly different with that in the acidic solution (pH=2). Approximately 95% loaded drug was released from the hydrogels in 4h in the PBS solution, while only about 50% loaded drug was released from the hydrogels in 4h in the acidic solution. Conclusion: The developed carboxymethyl chitosan hydrogels with promising porosity and pH sensitivity show potential application value in drug delivery systems.