Adsorptive stripping voltammetric determination of fluoroquinolones in pharmaceuticals

Sensitive cathodic stripping voltammetric methods have been developed for two fluoroquinolone antibacterial drugs, norfloxacin and enoxacin. Dimethylformamide (DMF) and 0.1 M hydrochloric acid were used as media for norfloxacin and enoxacin respectively. Potassium chloride was used as base electrolyte. A reduction wave was observed for norfloxacin within the range of -1.02 to -1.13V and for enoxacin within -0.93 to -1.07V. Linear calibration ranges for norfloxacin and enoxacin were observed within 20-100μg/mL and 1-40μg/mL with detection limits of 10μg/mL and 50ng/mL respectively Relative standard deviations (RSD) for the analysis of 10μg/mL norfloxacin and 10μg/mL enoxacin (n=5) were observed 1.l% and 0.2%. The presence of glucose, lactose, sorbitol, gum arabic, starch, magnesium stearate, methylparaben and propylparaben did not affect the determination. The methods were used for the analysis of pharmaceutical preparations and quantitative recoveries were obtained with relative deviation within 1.6-4.75%.