Summary
Cefixime (CFX) absorption kinetics after oral administration to humans was studied. Four distinct models, incorporating a delay of absorption and first-order elimination kinetics, i.e. first-order absorption (M1), zero-order absorption (M0), Michaelis-Menten type absorption (MM) and Michaelis-Menten type absorption with ‘an absorption window’ (MM-Δt) were used to fit concentration data of CFX in 10 Chinese men following an oral dose of 400 mg. r2 and AIC were selected as measures of goodness-of-fit. The results show that the MM-Δt model provided a better fit than the other three models. The kinetic parameters were estimated as follows: Vmax′=10.80±3.80 mg.l−1.h−1; Km′=88.31±2.75 μg.ml−1; Δt=4.75±0.85 h; T1/2=4.20±0.92 h; Tmax=5.20±0.92 h; and Cmax=6.04±1.70 mg.l−1.