羧甲基壳聚糖水凝胶制备及其在药物控释中的应用

THE SYNTHESIS OF CARBOXYMETHYLCHITOSAN HYDROGEL AND THE APPLICATION IN DRUG CONTROLLED RELEASE SYSTEMS

以戊二醛为交联剂制备了一系列羧甲基壳聚糖pH敏感水凝胶 .研究了合成条件对羧甲基壳聚糖水凝胶溶胀性能的影响 .实验结果表明羧甲基壳聚糖的脱乙酰度、交联剂用量对水凝胶溶胀率的影响较大 .pH=3 0时 ,水凝胶收缩 ,而pH =1 0 ,5 0 ,7 4 ,9 0时 ,水凝胶溶胀 ,且在碱性条件下水凝胶的溶胀率远大于酸性条件下的溶胀率 .包埋在此水凝胶中的水杨酸释放随载药介质的pH值和水凝胶半径大小的变化而显著不同 ,pH =1 0条件下载药的水凝胶的释药率大于pH =7 4 ,12 0条件下的释药率 ,且水凝胶的半径越大 。

pH-sensitive hydrogels based on carboxymethylchitosan (CMCTS) were synthesized by using glutaraldehyde as cross-link agent. The effects of the degree of deacetylation of CMCTS and the dosage of crosslinker on the swelling behaviors of hydrogels have been studied. The results show that the two factors related above regulate their swelling behavior. At pH = 3.0, the hydrogel shrinked most while swelled at pH = 1.0, 5.0, 7.4, 9. 0. In general, the swelling ratio(SR) of this hydrogel in alkaline solution is much larger than that in acidic solution. The release behavior of salicylic acid (SA) entrapped in the hydrogels was of distinctly difference with the changes of pH value of loading medium and the semidiameter of the hydrogels. The release of salicylic acid in CMCT hydrogel in the medium of pH = 1.0 was much quicker in pH = 7.4, 12.0, and the release speed and release ratio increase with the partical size.