Objective: To investigate the effects of concomitant food intake on the pharmacokinetics of a single oral dose of moxifloxacin 400mg.
Design: This was a randomised 2-way nonblinded crossover study in healthy volunteers.
Participants: 18 young, healthy, male volunteers were enrolled in the study, of whom 16 were considered evaluable for the pharmacokinetic analysis.
Methods: Moxifloxacin was given under 2 conditions separated by a 1-week washout period: fasted and fed (immediately after a standardised high fat breakfast). Concentrations of moxifloxacin in serum were determined by a validated high performance liquid chromatography procedure with fluorescence detection.
Outcome measures: Pharmacokinetic parameters such as maximum concentration (Cmax), time to reach Cmax (tmax), area under the concentration-time curve from zero to 48 hours (AUC48h), AUC from zero extrapolated to infinity (AUCinfinity) and elimination half-life (t1/2z) were estimated using noncompartmental methods. The natural logarithms of AUC and Cmax were analysed using analysis of variance. Bioequivalence of the 2 treatments was determined at the 5% significance level with the two 1-sided tests procedure and limits of 80% and 125% for AUC and 70 to 143% for Cmax.
Results: The mean serum concentration versus time profiles were similar between the 2 treatments. The geometric mean AUCinfinity values under fed and fasted conditions were almost identical, 37.7 versus 38.5 mg/L x h, respectively [90% confidence interval (CI) of the ratio of fed versus fasted based on geometric least-square means was 0.95, 1.00]. Geometric mean Cmax values were slightly reduced by food, 2.5 versus 2.8 mg/L, respectively (90% CI of fed versus fasted based on geometric least-square means was 0.78, 0.98). The absorption of moxifloxacin seems to be mildly delayed because of the effect of food; the median tmax values were 1.0 and 2.5 hours for fasted and fed conditions, respectively. The single oral dose of moxifloxacin 400mg was well tolerated when taken with and without food.