Introduction: In this assay, a new selective online heart-cutting Liquid Chromatographic
method was developed for the quantification of gemifloxacin in serum samples.
Experiment: Separations were carried out with following systems; 1st chromatographic system consisting
of 50 x 2.1 mm Pentafluorophenyl propyl pre-separation column with acetonitrile and 0.01 M orthophosphoric
acid solution mixture (20:80) as mobile phase and the 2nd
chromatographic system consisting
of 150 x 4.6 mm C18 separating column with methanol and 0.02 M ortho-phosphoric acid solution mixture
(40:60) as mobile phase. Two systems were connected with a 6-port valve having 0.2 mL sample
loop and separations were performed continuously through injections. Detection wavelength has been
selected as 272 nm for both systems and moxifloxacin was used as internal standard. Extraction of drug
substances from serum samples was performed using protein precipitation method with methanol and the
calibration curve was linear over a concentration range of 0.5-5.0 µg/mL. The developed method was
applied to serum samples collected from a volunteer who has received 320 mg gemifloxacin orally and
pharmacokinetic parameters were calculated.
Conclusion: In conclusion, the developed method is highly selective and reproducible and can be applied
for the pharmacokinetic study of gemifloxacin.