Capillary Electrophoresis Method for Determination of Escitalopram Oxalate in Urine Samples and Different Dosage Forms

Abstract Application of capillary electrophoresis (CE) has become a rapidly growing analytical technique for the estimation of drugs in pharmaceutical dosage forms and biological fluids. In this study, an effective and sensitive method was developed for the determination of escitalopram oxalate (ESC-OX) by CE with diode-array detection at 200 nm. The separation was achieved by a fused silica capillary with 40 cm effective length (48.5 cm total, 75 μm i.d.). The background electrolyte was composed of 15 mM phosphate buffer (pH 2.5). The applied potential was 22.5 kV, and the samples were injected at 50 mbar pressure for 10 s. Metoprolol was used as an internal standard (IS). The migration time under these optimum conditions was 6.51 ± 0.07 and 6.73 ± 0.08 min for ESC-OX and IS, respectively, with total run time 7 min. The method was validated for linearity, precision, accuracy, specificity and sensitivity. The limit of detection was calculated as 3.85 and 5.07 ng mL−1 for standard and urine samples, respectively. The developed method was employed successfully for the determination of ESC-OX in different pharmaceutical dosage forms and spiked human urine after simple liquid–liquid extraction with good recovery.