JOURNAL OF THE IRANIAN CHEMICAL SOCIETY, vol.18, no.4, pp.739-750, 2021 (SCI-Expanded)
Escitalopram oxalate (ESC-OX) is among the most currently used antidepressant drugs. This study aimed to determine ESC-OX in human urine and different pharmaceutical dosage forms via the electrochemical method. The electrochemical behavior of ESC-OX was investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques at hanging mercury dropping electrode (HMDE). The maximum reduction potential was determined to be - 0.55 and - 0.57 V at pH 6.5 in a cell containing 5% (v/v) methanol and 0.3 M KCl. Under the optimized conditions, the calibration curve of the cathodic peak current versus the concentration was linear in the range of 4.143-29.0 mu g mL(-1). The LOD and LOQ were found to be 1.15 mu g mL(-1)and 1.31 mu g mL(-1), 3.490 mu g mL(-1)and 3.97 mu g mL(-1)for pharmaceutical and urine samples, respectively. The investigation of electrochemical reduction of ESC-OX on the HDME by using CV resulted in a quasi-reversibility, mainly diffusion-controlled reaction that involves a four-electron reduction of the nitrile group. For analytical purposes, a stable and well-defined peak was obtained in DPV mode. The average accuracy was found to be 101.60% +/- 0.48 and 99.72% +/- 5.64 for pharmaceutical and urine samples, respectively. Moreover, the developed method was precise with RSD % below 2% for both samples. The validation of the developed method was carried out as stated in the ICH Q2(R) 1 guideline. The proposed technique was effectively utilized for the determination of ESC-OX in different pharmaceutical formulations and urine samples. Neither excipients nor endogenous substances have electroactive interferences.