Study of electrochemical behavior of escitalopram oxalate using hanging mercury drop electrode and its determination in human urine and pharmaceuticals

Abstract

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 µg mL−1. The LOD and LOQ were found to be 1.15 µg mL−1 and 1.31 µg mL−1, 3.490 µg mL−1 and 3.97 µg 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.