HPTLC method for the determination of gatifloxacin in human plasma

A high performance thin layer chromatographic method for the determination of gatifloxacin in human plasma using paracetamol as internal standard is proposed. Gatifloxacin in plasma was extracted with dichloromethane at pH 4.5 (phosphate buffer). The dichloromethane layer was evaporated and residue was reconstituted with ethanol and quantified using the mobile phase consisting of chloroform:methanol:ethanol:ammonia (4:2:2:2% v/v/v/v). The limit of quantitation was 50 ng/spot. The % RSD of the intra-day and inter-day was less than 15. The method was found to be simple, sensitive, rapid and could be used in the pharmacokinetic study involving human volunteers.