Assessment of Tacrolimus Absorption From the Human Intestinal Tract: Open-Label, Randomized, 4-Way Crossover Study

Tacrolimus was absorbed from the duodenum to the colon in these male subjects, although differences were observed in the value of AUC0-24, possibly due to variation in cytochrome P450 3A4 activity in the intestine. Although this study was conducted in small group of healthy fasting men, the present results indicate that tacrolimus is suitable for MR formulation development due to a wide absorption window throughout the intestine in humans.