Pharmacokinetic comparison of two levofloxacin 100-mg tablet formulations and determination of time point appropriately reflecting its area under the curve

Levofloxacin is a broad-spectrum antibiotic with activity against gram-positive and -negative bacteria. This study compared the pharmacokinetics (PK) and evaluated the bioequivalence of two levofloxacin 100-mg tablet formulations. An open, randomized, two-way crossover study was conducted in 28 healthy volunteers. The reference (Cravit Tab 100-mg, Jeil) or test (Levobacter Tab, Seoul) formulation was administered and serial blood samples were collected over 24 h for PK analysis. Levofloxacin plasma concentrations were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The correlation of levofloxacin concentration at various time points with the area under the concentration time-curve over the time interval from 0 extrapolated to infinity (AUCinf) was estimated to determine the best reflected time point. The average half-life, maximum plasma concentration (Cmax), and AUClast were comparable. The 90% confidence intervals (CIs) of the geometric mean ratio (GMR test/reference) of AUClast and C max were 0.8200–1.0633 and 0.9474–1.0643 respectively. Both formulations were tolerated with no clinically relevant safety issues. Plasma levofloxacin concentrations at various time points correlated well with the AUCinf, and showed high correlation coefficients (r > 0.7, P < 0.001) for both drugs 8 and 12 h after ad¬ministration. Both formulations showed similar PK profiles while levofloxacin plasma levels after administration indicated their bioequivalence. The Cmax and AUClast GMR 90% CIs were 0.80-1.25. Moreover, 12 h was the best time point to predict the AUCinf and therefore suitable for therapeutic drug monitoring. KCI Citation Count: 0