High-Performance Liquid Chromatography–Tandem Mass Spectrometry Method for Simultaneous Quantification of Carbamazepine, Oxcarbazepine, and Their Main Metabolites in Human Serum

Turbulent Flow Liquid Chromatography-Tandem Mass Spectrometry Methods for Antiepileptic Drug Quantitation in Serum

Epilepsy is characterized by abnormal electrical discharges in the brain that result in unprovoked seizures. Pharmacotherapy with antiepileptic drugs (AED) can help control the incidence of epileptic seizures. AED therapeutic regimens often need to be individually tailored. Therapeutic drug monitoring (TDM) of AED is required to optimize therapeutic efficacy and minimize the risk of any associated destructive toxicities. We describe a turbulent flow liquid chromatography-tandem mass spectrometry (TFC-MS/MS) method for the detection of seven different AED in human serum. TFC-MS/MS testing was performed using a TLX-2 online sample preparation liquid chromatography (SPLC) system coupled to an API 5500 Q-Trap tandem mass spectrometer. Quantification of 10,11-dihydro-10-hydroxycarbamazepine, lacosamide, lamotrigine, levetiracetam, rufinamide, topiramate, and zonisamide was, respectively, performed using calibration curves (2-60 μg/mL, R2 > 0.99) with precisions of <10%.

Simultaneous quantification of oxcarbazepine and its active metabolite in spiked human plasma using ultra performance liquid chromatography-MS/MS

Aim: Clinical monitoring of oxcarbazepine (OXC) and its metabolite licarbazepine (MHD) in biological matrix requires a sensitive and validated analytical method. The aim of this study is to develop and validate an optimized ultra performance liquid chromatography-MS/MS based bioanalytical method for the simultaneous estimation of OXC and its metabolite MHD in human plasma, using deuterated internal standard method. Materials & methods: A reverse phase ultra performance liquid chromatography analysis and mass spectrometric detection was performed using electrospray ionization in positive ion mode as interface, multiple reaction monitoring as mode of acquisition. Results & conclusion: The linearity range was 10-4011 ng/ml for OXC and 40-16061 ng/ml for MHD. The kinetic parameters were calculated and compared for bioequivalence. This method fulfilled the validation guidelines, could be employed for determining bioavailability and in new formulation development studies.

Development of an online solid-phase extraction-liquid chromatography-mass spectrometric analysis of oxcarbazepine and its active metabolite licarbazepine from plasma with a direct injection step

We developed an online solid phase extraction procedure using a hydrophilic-lipophilic balance sorbent, with reversed-phase liquid chromatography-high-resolution mass spectroscopy for the determination of oxcarbazepine and its active metabolite licarbazepine in plasma samples. The analytes were detected using a high-resolution Q Orbitrap mass spectrometer with targeted-selected ion monitoring (t-SIM) in positive scan mode. Under the optimized conditions, the method was linear with R² values >0.99. The method was linear from 0.008 to 2.000 μg mL^-1 and the lower limit of quantification was 0.008 μg mL^-1 for both oxcarbazepine and licarbazepine. Recoveries ranged from 92.34 to 104.27% and from matrix-matched samples from 94.26 to 104.19%. The intraday and interday precision RSD values were <9.13% with an associated accuracy of 92.71 to 104.06%. The total time for the one step online procedure was only 8 min. This method provides a direct and accurate measurement for therapeutic drug monitoring of oxcarbazepine and its active metabolite licarbazepine.