Voltammetric quantitative analysis of vildagliptin in bulk form and spiked human serum at a modified electrode

Abstract

The electrochemical behavior of Vildagliptin (VILD) was studied using the cyclic voltammetric technique in an aqueous Britton–Robinson (BR) universal buffer solution of various pH levels between 4.0 and 10 at a 5% calcium-montmorillonite clay modified with carbon paste electrode surface (5% Ca-MMT/CPE). The results exhibited an irreversible anodic peak at about 1.238 V versus Ag/AgCl, KCl (3 mol L−1). The anodic peak was found to be diffusion–adsorption controlled. The possible reaction mechanism is estimated taking into consideration of the calculated electrons and protons number transferred on the electrode/electrolyte interface using the cyclic voltammetric technique. VILD was found to adsorb onto the surface of 5% Ca-MMT/CPE in a monolayer surface coverage of 3.0 × 10−12 mol cm−2. A validated square wave voltammetry (SWV) technique for VILD determination was performed. The calibration curve of VILD onto the 5% Ca-MMT/CPE surface was linear in the concentration range of 1.0–110 nmol L−1 with the mean limits of detection and quantification was 0.285 and 0.950 nmol L−1, respectively, in the bulk form. The proposed procedure for the assay of VILD in bulk form, dosage form, and spiked human serum has the advantage of being simple, rapid, sensitive, and inexpensive compared to other analytical methods. The described method showed an excellent performance for the trace determination of VILD in its formulation without interference from excipients.Graphical abstract