Voltammetric and differential pulse determination of roxithromycin

The oxidative behavior of antibiotic roxithromycin standard was studied at a gold electrode in 0.05 M NaHCO3 using cyclic linear sweep voltammetry and differential pulse voltammetry. It was found that the value of the oxidative peak of pure roxithromycin at 0.81 V vs. SCE in 0.05 M NaHCO3 at a scan rate of 50 mV s−1 is a linear function of the concentration in a range 0.10006–0.654 mg cm−3. It was also found that peak current density at 0.75 V vs. SCE at a scan rate of 2 mV s−1, pulse amplitude of 25 mV and pulse time of 0.1 s exhibits linear dependence on the concentration of roxithromycin from 0.1006 to 0.476 mg cm−3. Roxithromycin as a content of solid dosage form and urine was quantitatively determined and the obtained results were checked by HPLC.