Oral bioequivalence of three ciprofloxacin formulations following single-dose administration: 500 mg tablet compared with 500 mg/10 mL or 500 mg/5 mL suspension and the effect of food on the absorption of ciprofloxacin oral suspension.

Abstract

The oral bioequivalence and tolerability of two ciprofloxacin formulations (tablet and suspension) and the effect of food on the absorption of ciprofloxacin oral suspension were investigated. Sixty-eight young, healthy male subjects participated in two separate, randomized, crossover studies. In study 1, ciprofloxacin as a single 500 mg tablet or as 500 mg/10 mL oral suspension was administered in a fasted state on day 1. In study 2, subjects participated in a three-way crossover study in which ciprofloxacin suspension was administered as 500 mg/10 mL in a fasted state, or 500 mg/10 mL with food, or 500 mg/5 mL in a fasted state. Plasma ciprofloxacin concentrations were measured by high-performance liquid chromatography. Standard pharmacokinetic parameters were estimated using non-compartmental methods. In study 1, geometric mean Cmax values of ciprofloxacin following the single 500 mg tablet and 500 mg/10 mL suspension doses were 2.36 and 2.18 mg/L, respectively; corresponding geometric mean t(max) values were 1.1 and 1.6 h, respectively. Geometric mean AUC(0-infinity) values were 12.0 and 11.8 mg x h/L, respectively. In study 2, geometric least squares mean Cmax values following ciprofloxacin 500 mg/10 mL and 500 mg/5 mL suspension during fasted conditions were 1.54 and 1.59 mg/L, respectively. Corresponding geometric least squares mean AUC(0-infinity) values were 7.3 and 8.0 mg x h/L. Administration of ciprofloxacin 500 mg/10 mL suspension, in either a fasted or fed state, was not associated with significant changes in Cmax (1.54 mg/L for fasted vs 1.37 mg/L for fed) or AUC(0-infinity) values (7.28 mg x h/L for fasted vs 8.19 mg x h/L for fed). Each ciprofloxacin formulation was well tolerated for the duration of each study. These studies demonstrated bioequivalence between ciprofloxacin 500 mg tablet and two strengths of ciprofloxacin suspension (500 mg/10 mL and 500 mg/5 mL). Bioavailability was unaltered by food.