Dissolution testing as a prognostic tool for oral drug absorption: Dissolution behavior of glibenclamide

Purpose. The dissolution behavior of two commercially available glibenclami de formulations was tested in various media. The aim of the study was to in vestigate whether the use of biorelevant dissolution media (BDM) would be a dvantageous over the use of standard media for predicting the in vivo perfo rmance of the two formulations. Methods. The dissolution tests were performed using USP 23 apparatus 2. Con ventional buffers and USP media were compared with two BDM containing diffe rent amounts of lecithin and sodium taurocholate. Results. The dissolution of two drug powders was highly dependent on wettin g, particle size, pH, and the composition of the medium used. In addition, the dissolution behavior of the two glibenclamide formulations showed diffe rences in all media tested. The dissolution results of the two formulations were compared with those from an in vivo bioequivalence study undertaken b y the central quality control laboratory of the German pharmacists (ZL). Th e bioequivalence criterion set by the ZL requires mon than 80% drug release within 10 minutes. Results in FaSSIF one of the BDMs, met the ZL criterion and this medium was also able to discriminate between the two formulations . This was not the case for the other media tested. Conclusions. The study indicates that BDM are better able to discriminate b etween glibenclamide formulations than standard dissolution media.