Simple and rapid determination of loratadine in pharmaceuticals using square-wave voltammetry and a cathodically pretreated boron-doped diamond electrode

Abstract

The electrochemical behavior and determination of antihistaminic drug loratadine using a cathodically pretreated boron-doped diamond electrode (BDDE) are proposed. This is the first voltammetric method using a carbon-based electrode material. The anodic peak potential for loratadine at the BDDE was 1.67 V (vs. Ag/AgCl (3.0 mol L⁻¹ KCl)) by cyclic voltammetry in a 0.50 mol L⁻¹ HClO₄ solution, whereas at the glassy carbon electrode (GCE), no peak potential was observed, due to the narrow potential window of this electrode. Using the square-wave voltammetric technique (f = 50 Hz, a = 40 mV and ΔE_S = 2 mV), the obtained analytical curve was linear for loratadine concentrations ranging from 0.98 to 19 μmol L⁻¹. This simple, rapid and green analytical method was successfully applied to the determination of loratadine in pharmaceutical formulations. The results were in close agreement, with a 95% confidence level, with those obtained using comparative spectrophotometric method.