Development and validation of an enantioselective SFC-MS/MS method for simultaneous separation and quantification of oxcarbazepine and its chiral metabolites in beagle dog plasma

A rapid and sensitive assay based on supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS) has been developed and validated for the determination of oxcarbazepine (OXC) and its chiral metabolite licarbazine (Lic) in beagle dog plasma using carbamazepine as internal standard. Chiral analysis in a run time of only 3 min was performed on an ACQUITY UPC2 ™ Trefoil™ CEL2 column (3.0 × 150 mm, 2.5 μm) at 50 °C by isocratic elution with a mobile phase of supercritical carbon dioxide (purity ≥ 99.99%) and methanol (60:40, v/v) at a flow rate of 2.3 mL/min. The assay was linear over the concentration ranges 5-1000 ng/mL for OXC and 0.5-100 ng/mL for the enantiomers of Lic with corresponding lower limits of quantitation of 5 ng/mL and 0.5 ng/mL. Intra- and inter-day precisions were in the range 0.78-14.14% with accuracies in the range −10.80% to 0.42%. The method was successfully applied to a pharmacokinetic study involving a single oral administration of 16 mg/kg OXC as Trileptal@ tablets to beagle dogs.