Reverse phase-HPLC and HPTLC methods for determination of gemifloxacin mesylate in human plasma

Two simple, rapid, sensitive and economic chromatographic methods have been developed for determination of gemifloxacin mesylate in human plasma by using internal standard. First method depends on reverse phase high performance liquid chromatography. The plasma sample was extracted using chloroform:acetic acid (5.4:0.1, v/v). A concentration range from 30 to 600 ng/ml was used for calibration curve. The percent recovery of gemifloxacin mesylate was found to be 80.06–84.88. The mobile phase used consist of methanol:sodium acetate (1%):ortho phosphoric acid (65:35:0.5, v/v/v) with pH 2.1 and flow rate 0.8 ml/min in isocratic mode. The separation was carried out by UV-detector at wavelength 263 nm. Second method depends on high performance thin layer chromatography. The plasma sample was extracted using chloroform:acetic acid (5.9:0.1, v/v). A concentration range from 50 to 600 ng/spot was used for calibration curve. The percent recovery of gemifloxacin mesylate was found to be 80.01–86.17. The mobile phase used consists of ethyl acetate:methanol:ammonia (8.0:4.0:3.0, v/v/v). Densitometric analysis was carried out at wavelength 254 nm. The Rf values for gemifloxacin mesylate and linezolide were 0.33 ± 0.03 and 0.69 ± 0.03 respectively. The stability of gemifloxacin mesylate in plasma was confirmed during three freeze–thaw cycles (−20 °C), on bench during 12 h. The proposed method was validated statistically and by performing recovery study for determination of gemifloxacin mesylate in human plasma.