具有不同微结构的壳聚糖/淀粉复合材料的性能及其应用

The Property of Chitosan with Different Microstructure/Starch Composite Material and Its Application

摘要:

本文选择4种具有不同微结构的壳聚糖，与淀粉形成复合材料，并对复合溶液的流变、粘弹性能以及复合薄膜的机械性能进行探讨，利用复合材料对含药片剂进行薄膜包衣，考察其控释性能。实验结果发现，壳聚糖/淀粉复合溶液具有假塑性流体特征，壳聚糖粘均分子量越大，剪切稀化现象越明显。同时，在复合薄膜制备过程中，壳聚糖可促进淀粉分子链的排布，提升复合薄膜的抗拉强度、断裂伸长率，调控壳聚糖微观结构可改善复合薄膜的机械性能。当包衣片剂运转至模拟肠液，借助壳聚糖上的-NH3+与淀粉的-OH间的氢键作用，片剂外可形成凝胶层，阻碍药物的释放，壳聚糖分子量越大，药物从复合薄膜包衣片剂中释放的累积量越小。以粘均分子量2.543×105 g/mol的壳聚糖CTS60与玉米淀粉制备的复合薄膜包衣片剂，约有70.59%药物可递送至肠道，其中有21.83%释放于模拟小肠，48.77%释放于模拟结肠，表现出一定的控释性能。

Abstract:

In this study, four kinds of chitosan with different microstructures were chosen, and blended with starch to form the composite material. The rheological behavior, viscoelastic property and tensile property of composite material were investigated. Moreover, the releasing property of tablet coated with chitosan/starch composite material was analyzed by in vitro test. The results showed that chitosan/starch solution presented pseudoplastic behavior. The fluid shear-thinning behavior was enhanced as the viscosity average molecular weight of chitosan increasing. The tensile strength and elongation of composite film were improved due to the rearrangement of chitosan and starch chains during the preparation. In the in vitro releasing test, while transported to simulated intestinal fluid, a chitosan/starch gel-like layer was formed outside the coating tabletby the hydrogen bond between -NH3+ of chitosan and -OH of starch, which restricted the drug releasing. As viscosity average molecular weight of chitosan increasing, less drug released. The tablet coated by composite material with 2.543×105 g/mol molecular weight chitosan showed a well-controlled releasing property, with 70.59% drug releasing in simulated small intestine fluid (21.83%) and simulated colon fluid (48.77%).