Figure 5:

Simulated external concentrations (mg/kg bw/day) versus area under the curve of plasma concentrations during the last 24 hours (AUC; in μmole*h/L) of the parent and the metabolite, where hepatic metabolism of parent (hypothetical Chemical A) and urinary excretion of metabolite of Chemical A are either saturable or first-order. Two conditions are evaluated: the maximum rate of metabolite clearance is half of the maximum rate of parent metabolism (panel A); or the maximum rate of metabolite clearance is double the maximum rate of parent metabolism (panel B).