Achiral LC-MS/MS and chiral SFC-MS methods for quantification of methoxphenidine and O-desmethyl-methoxphenidine metabolite in rat serum and brain.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences June 1, 2025 Natalie Paškanová, Magdaléna Vágnerová, Bronislav Jurásek et al. 1 citation
Methoxphenidine (MXP), a dissociative anaesthetic derivative, is increasingly abused, but forensic and clinical data on its metabolism and enantiomers are limited. Researchers developed and validated achiral LC-MS/MS and chiral SFC-MS methods to quantify MXP and its primary metabolite, O-desmethyl-methoxphenidine (dmMXP), in rat serum and brain after a single subcutaneous dose of racemic MXP. Serum MXP peaked at 1600 ng/mL at 0.5 hours and decreased to 5.87 ng/mL at 24 hours; brain MXP peaked at 13200 ng/g at 0.5 hours and fell to 36.1 ng/g at 24 hours. (S)-MXP concentrations in brain appeared higher than (R)-enantiomer concentrations. The methods enable pharmacokinetic studies and provide tools for forensic and clinical toxicology.