Schematic diagram of the dynamic gastrointestinal model used in this study. (A, B) 500-ml Erlenmeyer flasks representing the GC and IC; (C, D) pH meters monitoring the pH in the GC and IC; (E, F, G) peristaltic pumps delivering gastric fluid (flow rate, 0.33 ml/min) in the GC and intestinal fluid (flow rate, 0.33 ml/min) and 2 or 4% bile (flow rate, 0.5 ml/min) in the IC; (H) peristaltic pump transferring the gastric contents (flow rate, 1.1 ml/min) in the IC; (I) shaking water bath stabilized at 37°C.