Differential Pulse Voltammetric Determination of Sildenafil Citrate (Viagra®) in Pharmaceutical Formulations Using a Boron-Doped Diamond Electrode

Abstract

Abstract The determination of sildenafil citrate using differential pulse voltammetry and a cathodically pre-treated boron-doped diamond electrode is described. The obtained analytical curve is linear in the sildenafil concentration range 7.3 × 10−7 − 7.3 × 10−6 mol L−1 in a 0.1 mol L−1 H2SO4, with a detection limit of 6.4 × 10−7 mol L−1. The proposed method, which is fast and simple to carry out, was successfully applied in the determination of sildenafil citrate in Viagra® pharmaceutical formulations, with results in close agreement (at 95% confidence level) with those obtained using a comparative HPLC method. Keywords: Boron-doped diamond electrodeDifferential pulse voltammetryPharmaceutical formulationsSildenafil citrate (Viagra®) determination The authors gratefully acknowledge financial support and scholarships from the Brazilian funding agencies FAPESP (2007/07692-4), CAPES, and CNPq. Notes a Average of 3 measurements. b 100 × (DPV value – HPLC method)/HPLC method.