Improving the Precision of Ibuprofen Free Acid and Its Salts in Vitro Dissolution Assays

Abstract

Researchers have questioned the predictive potential of in vitro dissolving tests for BCS class 2 weak
acids utilizing the Bio pharmaceutics Classification System (BCS) as an experimental design to
predict in vivo bioequivalence results. As a potential strategy for guaranteeing the discriminative
capability of the in vitro dissolving techniques, this study examined the influence of buffer
concentration media. Various salt forms of ibuprofen, as well as the free acid, were used to evaluate
this method. In order to improve the discriminative power of the in vitro dissolution tests, the
concentration of buffers used to prepare media that mimic intestinal conditions was adjusted to match
that of bicarbonate buffer, the most common species of buffer in living organisms, so that both sets of
samples reached the same surface pH (pH0). In order to enhance the resemblance to the in vivo
findings, a two-stage test was combined with a pretreatment at an acidic pH to mimic the
circumstances in the stomach. In order to more accurately represent the in vivo performance of the
different formulations, the 2-stage test allowed for a more physiologically realistic accounting for
variations in disintegration.