Differential pulse polarographic studies of levofloxacin antibiotic and its determination in pharmaceutical formulations and biological samples

Levofloxacin, a well-known laevorotatory isomer of antibiotic ofloxacin was studied for electrochemical activity on dropping mercury electrode. It gave well-defined symmetrical peak in Britton-Robinson buffer at pH 5.0 with peak potential, Ep =-1.314 V. Effect of various parameters including pH, scan rate, pulse amplitude, scan range etc were optimized. Under optimum conditions of pH 5.0, scan rate of 12 mV/s, pulse amplitude of 100 mV and scan range of-0.6 V to-1.6 V, the linear correlation between peak current and concentration extended from 0 to 1000 ppm with 3o detection limit OF 0.036 ppm. The method thus developed was applied for the estimation of levofloxacin in pharmaceutical formulations as well as urine and blood samples.