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[摘要]：In the last decades there has been continual interest in site-specific delivery to the colon. Recently, new types of site-specific delivery formulations have been developed for the treatment of ulcerative colitis and other colon related diseases. The aim of the present study was to establish a physiologically relevant IVIVC for two prototypes using a prospective in vitro study. Caffeine, a drug being absorbed along the entire gastrointestinal tract, was selected as a model drug. USP apparatus 3, the BioDis, was used for all experiments and the passage through the gastrointestinal tract was simulated with a physiologically based pH-gradient. Subsequently, the fraction of drug released in vitro was compared with the fraction of drug released in vivo, which was determined in humans in a separate study. Results indicated that the BioDis method is very useful in terms of predicting the site/timing and extent of drug release from the prototypes, since an a prior! IVIVC could be established. Moreover, from the results generated in the present study, it is obvious that novel pH- and time-based multi-unit formulations would improve selectivity of drug delivery to the distal ileum and the colon and therefore might be very helpful in the treatment of colonic diseases. (C) 2008 Published by Elsevier B.V. |
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