Voltammetric Assay of Metformin Hydrochloride Using Pyrogallol Modified Carbon Paste Electrode

The electrooxidative behavior and determination of metformin hydrochloride, anti-hyperglycemic drug, on a pyrogallol modified carbon paste electrode were investigated using cyclic voltammetry and differential pulse voltammetry. Metformin hydrochloride shows an irreversible oxidation behavior at all pH values of Britton-Robinson buffer (2.0-9.0). The peak current varied linearly in the range comprised between 8.0 x 10-7 and 6.0 x 10-6 mol/Lwith detection limit of 6.63 x 10-8 mol/Land limit of quantification of 2.21 x 10-7 mol/L. The method was proposed for the determination of metformin hydrochloride in dosage forms and urine.