Zhao Wenchang, Song Lijun, Deng Hongzhu, Yao Hui
School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, PR China.
Drug Dev Ind Pharm. 2009 May;35(5):594-602. doi: 10.1080/03639040802471176.
It is a challenge to deliver water-soluble drug based on hydrophilic matrix to colon because of swelling and erosion of polysaccharides in contact with media. In our study, guar-based hydrophilic matrix tablets containing water-soluble total alkaloids of Sophora alopecuroides prepared by wet granulation technique were evaluated. A novel method was established to investigate the changes of swelling and volume for guar-based tablets in undynamic state, which generally showed a rapid swelling and volume change in the first 9 h, then the hydrated speed slowed down. On the other hand, the influence of different pH of the media on water uptake and erosion of various guar-based formulations in dynamic state indicated that the hydrated constants in simulated gastric fluid (SGF) was higher than that in SIF, which followed varied mechanism of water penetration by fitting Davidson and Peppas model. The extent of erosion was between 22.4 and 32.6% in SIF within 360 min. In vitro sophoridine release studies in successive different mimicking media showed that the guar matrix tablets released 13.5-25.6% of sophoridine in the first 6 h; therefore it was necessary to develop the bilayer matrix tablet by direct-compressing coating 100 mg guar granula on core tablet. The initial release of coated tablet was retarded and the bilayer matrix tablet was suitable for colon target.
由于多糖与介质接触时会发生溶胀和侵蚀，将基于亲水性基质的水溶性药物递送至结肠是一项挑战。在我们的研究中，对采用湿法制粒技术制备的含有苦豆子水溶性总生物碱的瓜尔胶基亲水性基质片剂进行了评价。建立了一种新方法来研究瓜尔胶基片剂在静态下的溶胀和体积变化，其通常在前9小时内表现出快速的溶胀和体积变化，然后水合速度减慢。另一方面，不同pH值的介质对动态下各种瓜尔胶基制剂的水分吸收和侵蚀的影响表明，模拟胃液（SGF）中的水合常数高于模拟肠液（SIF）中的水合常数，通过拟合Davidson和Peppas模型，其遵循不同的水渗透机制。在360分钟内，SIF中的侵蚀程度在22.4%至32.6%之间。在连续不同的模拟介质中进行的体外槐定碱释放研究表明，瓜尔胶基质片剂在前6小时内释放了13.5%至25.6%的槐定碱；因此，有必要通过在片芯上直接压片包衣100mg瓜尔胶颗粒来制备双层基质片剂。包衣片的初始释放受到延迟，双层基质片剂适合结肠靶向。
