多糖凝胶骨架结肠定位给药缓释系统的体外释放研究

目的: 筛选多糖材料作为水凝胶骨架,以达到结肠定位释药目的.方法: 选用海藻酸钠、果胶、壳聚糖、瓜木耳胶与药物混和制粒,灌装肠溶或结肠溶胶囊,考察其在人工胃液,人工肠液及人工结肠液中的释放情况.结果: 难溶性药物的海藻酸钠骨架结肠溶胶囊在人工胃液和小肠液中均不释放,人工结肠液中3 h释药低于30%;果胶骨架肠溶胶囊在人工胃液亦不释药,人工肠液中5 h释药仅为15%.水溶性药物在人工肠液中5 h释放可达50%.结论: 难溶性药物的海藻酸钠/结肠溶胶囊和果胶/肠溶胶囊体外释放度结果符合结肠定位的要求,可以作为建立酶触发体外释放评价方法和体内评价的制剂形式.水溶性药物的果胶/肠溶胶囊是较理想的缓释剂型.

A Delivery Study on Polysaccharides Hydrogel Matrix for Colon-specific Drug-given and Sustained Release in Vitra

Objective: To screen polysaccharides materials as hydrogel matrix to obtain the colon-specific drug-given and sustained release. Method: The granules were prepared and putted into the enteric capsules or colonic capsules made with sodium alginate, pectin, chitosan and guar gum as hydrogel materials. The release behavior of the actives were investigated in 0.1M HCl, pH6.8 and pH7.8 phosphate buffer solution (PBS) to simulate stomach, small intestinal and large intestinal condition, respectively.Result: The insoluble active hardly released in 0.1M HCl and pH6.8 PBS medium and released less than 30% in pH 7.8 PBS from the colonic capsules. The active also did not release from the enteric capsules in 0.1M HCl. Even in the pH6.8 PBS, the active only released 15% in 5 hours. In contrast, the soluble drug released faster. The accumulated release percentage in 5 hours was 50% in the pH 6.8 PBS.Conclusion: The enteric and colonic capsules of the insoluble drug could be used as a new colon-specific drug delivery system for further study of the enzyme-triggered in vitro evaluation and in vivo evaluation. The enteric capsule of the soluble drug was the perfect prolonged-releasing dosage form.