Pharmacokinetic study of ofloxacin enantiomers in Pagrosomus major by chiral HPLC

( S )-(−)-Ofloxacin and ( R )-(+)-ofloxacin concentrations in the plasma of Pagrosomus major after drug treatment were detected by chiral high-performance liquid chromatography, and various pharmacokinetic parameters were calculated from these data. The elimination half-life of ( S )-(−)-ofloxacin was significantly shorter than that of the ( R )-(+) enantiomer. ( S )-(−)-Ofloxacin also had a significantly lower maximum plasma concentration, area under the concentration–time curve from zero to infinity, and mean residence time than ( R )-(+)-ofloxacin. However, the apparent volume of distribution and total body clearance of ( S )-(−)-ofloxacin were greater than those of ( R )-(+)-ofloxacin. The ratio of the ( S )-(−)- to ( R )-(+)-ofloxacin plasma concentration was always <1.0. Together, these data suggest that ( S )-(−)-ofloxacin was preferentially excreted and ( R )-(+)-ofloxacin was preferentially absorbed. Although the difference in pharmacokinetic parameters was small, the metabolic behavior of the ofloxacin enantiomers in P. major was enantioselective. Copyright © 2015 John Wiley & Sons, Ltd.