Kalantzi Lida, Page Richard, Nicolaides Eleftheria, Digenis George, Reppas Christos
Laboratory of Biopharmaceutics and Pharmacokinetics, National & Kapodistrian University of Athens, Panepistimiopolis, 157 71 Zografou, Athens, Greece.
Eur J Pharm Sci. 2008 Apr 23;33(4-5):445-51. doi: 10.1016/j.ejps.2008.01.014. Epub 2008 Feb 9.
Intragastric conditions can affect the performance of solid dosage forms. For two cases, the ability of in vitro methods to forecast these effects was investigated: first, the ability of cholestyramine to sequester bile salts in the fed small intestine and, second, disintegration times of hard gelatin capsules. After incubating cholestyramine for 90 min in milk gradually digested with pepsin, the binding of taurocholates from fed state simulating intestinal fluid onto the resin became non-specific and the affinity constant was reduced from 220 l/mole (without prior incubation) to 60 l/mole. These data are consistent with the comparatively poor performance of cholestyramine products when administered in the fed state. Scintigraphic studies showed that intragastric disintegration times of hard gelatin capsules are delayed in both the fasted and fed states according to the degree of cross-linking. These results were satisfactorily predicted by the in vitro disintegration times in fasted state simulating gastric fluid and in milk gradually digested with pepsin, whereas results were poorly predicted in compendial media. This work illustrates that recently proposed methods for simulating intragastric environment may be useful in predicting the performance of solid dosage forms.
胃内环境会影响固体剂型的性能。针对两种情况,研究了体外方法预测这些影响的能力:其一,考来烯胺在进食状态下的小肠中螯合胆汁盐的能力;其二,硬明胶胶囊的崩解时间。将考来烯胺在经胃蛋白酶逐渐消化的牛奶中孵育90分钟后,来自模拟进食状态肠液的牛磺胆酸盐与树脂的结合变得非特异性,亲和常数从220升/摩尔(未预先孵育)降至60升/摩尔。这些数据与考来烯胺产品在进食状态下给药时相对较差的性能一致。闪烁扫描研究表明,硬明胶胶囊在胃内的崩解时间在禁食和进食状态下均根据交联程度而延迟。这些结果在模拟禁食状态胃液和经胃蛋白酶逐渐消化的牛奶中的体外崩解时间中得到了满意的预测,而在药典介质中预测效果较差。这项工作表明,最近提出的模拟胃内环境的方法可能有助于预测固体剂型的性能。