Bioavailability of indomethacin capsules in humans (II): correlation with dissolution rate

The correlation between the dissolution rate and bioavailability in humans for five indomethacin capsules was investigated. The mean Cmax, Tmax and AUC24 of low gastric acidity in humans correlated well with the dissolution rate determined by the paddle method using a slow stirring rate. The Cmax of the high acidity subjects also correlated with the dissolution rates determined under mild conditions. However, the Tmax correlated with the dissolution rates determined under vigorous ones. The in vivo-in vitro correlation seems to have become complicated by an anomalous product whose dissolution was remarkably sensitive to environmental conditions. The correlation data also suggested that the deaggregation force on the adhesive agglomerate in human digestive tract might not be strong.