Detection of the Active Substance of an Anxiolytic Fabomotizole and Its Metabolite by Gas Chromatography/Mass Spectrometry with Positive Ion Chemical Ionization

Investigation of original drugs involves a study of pharmacokinetics and metabolism. Most investigations use HPLC/MS analysis. With the use of the active ingredient of a non-benzodiazepine anxiolytic Fabomotizole [2-(2-morpholinoethylthio)-5-ethoxybenzylimidazole dihydrochloride)] and its metabolite as an example, it was found that capillary gas chromatography-mass spectrometry with positive ion chemical ionization can be applied to detect insignificant amounts of polar biologically active substances, which are chemically stable during the passage of the gas chromatographic system; however, the analytes can be lost at different stages of the analysis.