Simultaneous Determination of Levocetirizine and Pseudoephedrine in Dog Plasma by Liquid Chromatography-Mass Spectrometry in the Presence of Dextrocetirizine

Purpose. This study describes the development of a rapid and sensitive LC-ESI-MS assay for simultaneous enantioselective determination of levocetirizine and pseudoephedrine in dog plasma in the presence of dextrocetirizine. Methods. Separations were achieved on an Ultron ES-OVM chiral column using the mobile phase consisting of 10 mM aqueous NH4OAc (pH 6.6) and acetonitrile (9:1 v/v). Results. The retention times of pseudoephedrine,...