Development of a New Separation Method for Escitalopram Oxalate and Its Related Impurities by Capillary Electrophoresis: Application on Valid and Expired Dosage Forms

Purpose Capillary Electrophoresis (CE) methods have a wide range of applications in industry and quality control laboratories for routine drug analysis. In the current study, a CE separation method was developed and validated for the concurrent detection of Escitalopram oxalate (ESC-OX) and three related impurities: Citalopram A, C, and D (CIT A, C, D). Additionally, the method was extended for the determination of impurities in both valid and expired dosage forms, Including Tablets and oral solutions. Methods Separation and analysis were accomplished in an untreated fused-silica capillary tube (48.5 cm total, 75 µm i.d.) within 20 minutes under an applied voltage gradient of 25 − 15 kV. Ideal separation was achieved using 40 mM phosphate buffer (pH 2.5) containing 60% Methanol as the background electrolyte. The apparatus was equipped with a diode array detector (DAD) to detect compounds at 210 nm. The established method was validated to accomplish the International Conference on Harmonization (ICH) requirements. Results The limit of detection was 7.44 x 10 ^− 3 , 7.83 x 10 ^− 3 , 11.56 x 10 ^− 3 and 9.19 x 10 ^− 3 µg mL ^− 1 for ESC-OX, CIT A, CIT C, and CIT D. The limit of quantitation was 0.025, 026, 0.038, and 031 µg mL ^− 1 . Conclusion the developed method provides a good complementary analytical method for routine analysis and stability testing.