Voltammetric Analysis of Antispasmodic Drug Drotaverine Hydrochloride in Pharmaceutical Preparations Andbiological Medium

Drotaverine hydrochloride is an antispasmodic drug widely used to relieve cramps or spasms of the stomach, intestines, and bladder.The electro reductive behavior of drotaverine has been investigated and one irreversible well-defined cathodic peak was observed at -1.04 V vs. Ag/AgCl (3M KCl). The electrochemical reduction and adsorption of drotaverine hydrochloride was studied in phosphate buffer medium by cyclic voltammetric (CV), differential pulse cathodic adsorptive stripping voltammetric (DPCAdSV) and square-wave cathodic adsorptive stripping voltammetric (SWCAdSV) techniques at hanging mercury drop electrode (HMDE). A fully validated, sensitive and reproducible cathodic adsorptive stripping voltammetric procedure for the trace determination of the bulk drug in pharmaceutical formulation and in biological medium has been developed.

The peak current showed a linear dependence with the drug concentration over the range 50 ng/mL to 25.6 µg/mL for SWCAdSV and 0.2 µg/mL to 51.8 µg/mL for DPCAdSV. The achieved LOD and LOQ were 7.1 ng/mL and 23.7 ng/mL by SWCAdSV and 33.84 ng/mL and 112.8 ng/mL by DPCAdSV respectively. The procedure was applied to the assay of the drug in tablets form with mean percentage recoveries of 100.4% with SWCAdSV and 100.2% with DPCAdSV. Applicability to assay the drug in spiked urine and serum samples were illustrated and minimum detectability were found to be 32.66 ng/mL and 49.83 ng/mL respectively.