Voltammetric Determination of Bromhexine in Pharmaceutical Products Using an Electrochemical Reduced Graphene Oxide—Enhanced Glassy Carbon Electrode

Abstract The content of Bromhexine HCl in pharmaceutical formulation was determined using adsorptive stripping voltammetry with a glassy carbon electrode (GCE) modified by electrochemical reduced graphene oxide (ErGO/GCE). The results revealed that the electrochemical oxidation of bromhexine HCl on the ErGO/GCE electrode is an irreversible process and adsorptive on the surface of the electrode. The optimal conditions included Britton–Robinson buffer at pH 5.5, an accumulation potential of 0 V, an accumulation time of 60 s, a scan rate of 0.025 V/s, and a linear concentration range from 1 × 10–8 to 5 × 10–6 mol L–1. The method demonstrated high sensitivity with a limit of detection (LOD) of 2.7 × 10–9 mol L–1 and a limit of quantification (LOQ) of 9 × 10–9 mol L–1. It exhibited good repeatability with a relative standard deviation (RSD) of less than 5%, and high accuracy with recovery values ranging from 96 to 105%. The method was successfully applied to the determination of Bromhexine HCl in pharmaceutical formulations.