Liu Fang, Lizio Rosario, Meier Christian, Petereit Hans-Ulrich, Blakey Peter, Basit Abdul W
Department of Pharmaceutics, The School of Pharmacy, University of London, London, United Kingdom.
J Control Release. 2009 Jan 19;133(2):119-24. doi: 10.1016/j.jconrel.2008.09.083. Epub 2008 Oct 4.
A novel double-coating enteric system was developed to accelerate drug release in conditions resembling the upper small intestine. The system comprises an inner coat (partially neutralised EUDRAGIT L 30 D-55 and organic acid) and an outer coat (standard EUDRAGIT L 30 D-55). Prednisolone tablets were coated with double layer formulations with inner coats neutralised to pH 5.6 in the presence of 10% citric acid or adipic acid. A conventional single coating was also applied for comparison purposes. There was no drug release from the single coated or double-coated tablets in 0.1M HCl for 2 h using USP II apparatus. The lag times of drug release in subsequent pH 5.6 phosphate buffer (to resemble the pH condition of the proximal small intestine) were 102, 42 and 28 min for the single coated, adipic acid and citric acid double-coated tablets respectively. The lag time for release from the double-coated tablets was further reduced to 5 min when the inner coat was neutralised to pH 6.0 in the presence of 10% citric acid. The rapid drug release from the double-coating system was associated with faster polymer dissolution rates compared to the single coating. The novel double-coated system has the potential to provide rapid drug release in the proximal small intestine, overcoming the limitations of conventional enteric coatings.
开发了一种新型双层肠溶系统，以加速药物在类似小肠上段的条件下释放。该系统包括内层包衣（部分中和的尤特奇L 30 D-55和有机酸）和外层包衣（标准尤特奇L 30 D-55）。在10%柠檬酸或己二酸存在下，将泼尼松龙片剂用内层包衣中和至pH 5.6的双层制剂包衣。为作比较，还应用了传统的单层包衣。使用USP II装置，单层包衣或双层包衣片剂在0.1M盐酸中2小时均无药物释放。在随后的pH 5.6磷酸盐缓冲液（模拟近端小肠的pH条件）中，单层包衣、己二酸双层包衣和柠檬酸双层包衣片剂的药物释放滞后时间分别为102、42和28分钟。当内层包衣在10%柠檬酸存在下中和至pH 6.0时，双层包衣片剂的释放滞后时间进一步缩短至5分钟。与单层包衣相比，双层包衣系统的快速药物释放与更快的聚合物溶解速率有关。这种新型双层包衣系统有可能在近端小肠提供快速药物释放，克服传统肠溶包衣的局限性。
