Differential pulse polarographic determination of moxifloxacin hydrochloride in pharmaceuticals and biological fluids

A simple, fast, sensitive and fully validated differential pulse polarographic ( DPP) method for the determination of trace amounts of moxifloxacin in pharmaceutics, serum and urine is reported. Moxifloxacin exhibited irreversible cathodic peak over the pH 5.00 - 11.00 in Britton - Robinson ( B - R) buffer. At pH 10.00 ( the analytical pH), a well-defined peak at -1.61 V versus saturated calomel electrode was obtained. The current has been characterized as being diffusion-controlled process. The diffusion current constant (i(d)) was 1.48 +/- 0.12 and the current - concentration plot was rectilinear over the range from 5 x 10(-7) to 1 x 10(-4) M with correlation coefficient (n = 10) of 0.995. The proposed method was applied to commercial tablets and average percentage recovery was in agreement with that obtained by spectrophotometric comparison method. The method was extended to the in vitro determination of moxifloxacin in spiked human serum and urine.