Abstract

Levodropropizine is a cough suppressant and easily oxidizable at the carbon-base electrodes. The electrooxidative behavior and determination of levodropropizine on glassy carbon and boron-doped diamond electrodes were investigated using cyclic, linear sweep, differential pulse, and square wave voltammetric methods. The dependence of the peak current and peak potentials on pH, concentration, nature of the buffer, and scan rate were examined. In this study, also simple and fully validated reverse phase-liquid chromatography (RP-LC) method for the assay of levodropropizine in syrup dosage form has been developed using X-Select RP-18 column (250x4.60 mm ID x 5μ) at 25 ºC with the mobile phase (containing 15 mM o-phosphoric acid) of acetonitrile:water (30:70, v/v) adjusted to pH 8.0. The proposed methods allow a number of cost and time saving benefits. Levodropropizine was also exposed to thermal, photolytic, oxidative stress, acid and base hydrolysis conditions, and the stressed samples were detected by the proposed LC method. The proposed methods were successfully applied for the determination of levodropropizine from pharmaceutical dosage forms.

Keywords: Glassy carbon electrode, Boron-doped diamond electrode, Pharmaceuticals, Levodropropizine, Voltammetry.