Electroanalytical investigation and determination of hepatitis C antiviral drug ledipasvir at a non-modified boron-doped diamond electrode

This study is about the use of the boron-doped diamond electrode pretreated electrochemically (anodic and subsequent cathodic) in the voltammetric determination of hepatitis C antiviral drug ledipasvir. Cyclic voltammetric measurements revealed that the compound yielded two well-separated irreversible oxidation peaks (P-A1 and P-A2) in acidic medium. The dependence of intensities of currents and potentials on electrode pretreatment, pH and nature of the supporting electrolyte, and other variables was investigated by square-wave voltammetry. Determination of ledipasvir was performed in Britton-Robinson buffer (pH 2.0) on the basis of both P-A1 and P-A2, which offered linear concentration ranges 0.5-60.0 mu g mL(-1) (5.6 x 10(-7)-6.8 x 10(-5) mol L-1) and 5.0-60.0 mu g mL(-1) (5.6 x 10(-6)-6.8 x 10(-5) mol L-1), respectively, with detection limits of 0.12 mu g mL(-1) (1.4 x 10(-7) mol L-1) and 0.76 mu g mL(-1) (8.6 x 10(-7) mol L-1). The practical applicability of developed methodology was tested by the assay of a fixed-dose combination tablet with sofosbuvir.