Ticagrelor Determination via Its Electrooxidation as the Standard, in Tablets and the Spiked Human Serum at Au Solid Electrode

Ticagrelor hydrochloride (TCG) is effective in platelet inhibition and useful for preventing cardiovascular death, myocardial infarction, or ischaemic stroke. The drug standard was investigated by cyclic voltammetry (CV) and quantitatively determined using differential pulse voltammetry (DPV) via its electrooxidation at Au electrode in 0.05 M NaHCO 3 . DPV showed a linear dependency of the anodic peak currents vs. TCG standard concentrations in the range from 3 × 10 -7 mol l -1 to 10 -5 mol l -1 with the values of the limit of detection (LOD) and the limit of quantification: 0.288 μmol l -1 and 0.96 μmol l -1 , respectively. Using the constructed and validated calibration curve, the values of unknown ticagrelor concentrations in Ticagrex® tablets and in human serum spiked with the standard were determined. Mechanistic study suggests that the oxidation proceeds at sulfur atom by removal of one electron as the rate determining step. In the next, fast step, formed radical cation loose another electron and sulfoxide is formed (with water molecule as nucleophile). The study of TCG degradation showed that at the Au, after 4.5 h of potential cycling, degradation occurs, which was confirmed by UV spectroscopy.