Abstract
Escitalopram is a widely used antidepressant and antianxiety agent in clinical setup. This study was aimed at developing and validating a very sensitive and specific bioanalytical method for the estimation of escitalopram in rat plasma using liquid chromatography coupled with tandem mass spectrometry as per the current United States Food and Drug Administration (May 2018) guideline. The mass spectrometer was operated in heated electrospray ionization mode with positive ion detection. The compounds were tuned and monitored by selected reaction monitoring scan mode. Imipramine hydrochloride was used as an internal standard. The extraction technique used to extract the analyte from the biological matrix was a liquid-liquid extraction technique. The chromatographic separation was done by using methanol:ammonium formate (2 mM, pH 3.00) (90:10 %v/v) as mobile phase with the flow rate of 0.500 ml/min with a run time of 2.10 min. Detection and quantification were performed under selective reaction monitoring using heated electron spray ionization mode. The mass transition monitored for escitalopram was 325.200 m/z (fragments 108.98 and 262.00 m/z) and for internal standard imipramine 281.200 m/z (fragments 58.20 and 86.19 m/z). This method demonstrated acceptable performance and was successfully applied for the estimation of escitalopram in rat plasma at 0.050 to 39.708 ng/ml range.