The Gut in a Beaker: More Challenges for In Vitro Testing

Abstract

The in vitro testing of drug formulations is an essential safety/quality test in formulation assessment, process evaluation and batch release. In addition, it is desirable that the media be physiologically relevant, assist in the prediction of IVIVC and provide data that could be used in computer modelling. The number of relevant chemical variables has expanded with the adoption of biorelevant fluid compositions for fasted and fed states and the expansion of simulated gastric and intestinal fluids into simple colonic media. Dissolution in variants of these media is justified on the grounds of human variability and diet, but the number of permutations possible eventually becomes prohibitively large for the pharmaceutical industry. A compromise between a minimum set of compositions and the chance of missing what would be clinically significant effect has to be balanced. Over a number of iterative processes based on the design of experiments approach, we have attempted to progress towards a minimized matrix of compositions.