Ketamine metabolites with antidepressant effects: Fast, economical, and eco-friendly enantioselective separation based on supercritical-fluid chromatography (SFC) and single quadrupole MS detection

摘要

Graphical abstract Display Omitted Highlights ? An efficient, ecological and fully validated SFC-MS method for the determination of ketamine enantiomers and their metabolites is reported. ? S -norketamine, R -norketamine, S -dehydronorketamine, R -dehydronorketamine, (2 R ,6 R )- and (2S,6S)-hydroxynorketamine in human urine were separated in a single run. ? Compared to existing LC–MS/MS methods, the presented SFC technique is four times faster in the separation of the metabolites (2 R ,6 R )- and (2 S ,6 S )-hydroxynorketamine. ? The method can aid studies aiming at the development of therapeutic options for major depression avoiding side-reactions and drug addiction. Abstract Increasing evidence accumulates that metabolites of the dissociative anesthetic ketamine contribute considerably to the biological effects of this drug and could be developed as next generation antidepressants, especially for acute treatment of patients with therapy-refractory major depression. Analytical methods for the simultaneous determination of the plethora of hydroxylated, dehydrogenated and/or demethylated compounds formed after administration of ketamine hydrochloride are a prerequisite for future clinical investigations and a deeper understanding of the individual role of the isomers of these metabolites. In this study, we present development and validation of a method based on supercritical-fluid chromatography (SFC) coupled to single quadrupole MS detection that allows the separation of ketamine as well as all of its relevant metabolites detected in urine of healthy volunteers. Inherently to SFC methods, the run times of the novel protocol are four times shorter than in a comparable HPLC method, the use of organic solvents is reduced and we were able to demonstrate and validate the successful enantioselective separation and quantification of R - and S -ketamine, R - and S -norketamine, R - and S -dehydronorketamine and (2 R ,6 R )- and (2 S ,6 S ) - hydroxynorketamine isomers differing in either constitution, stereochemistry, or both, in one run. The developed method may be useful in investigating the antidepressant efficacy of ketamine in clinical trials.