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

Simultaneous Determination of Multiple Anti-Seizure Medications in Human Plasma Using High-Performance Liquid Chromatography-Tandem Mass Spectrometry with Positive/Negative Ion-Switching Ionization Mode for Therapeutic Drug Monitoring

Monotherapy or combination therapy with anti-seizure medications (ASMs) remains the cornerstone of epilepsy treatment. Therapeutic drug monitoring is important for individualized ASM treatment and for optimizing outcomes in patients with epilepsy. Therefore, the simultaneous and accurate quantification of ASMs is necessary and helpful for clinical use. In this study, a new method was developed to simultaneously quantify carbamazepine, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, perampanel, sodium valproate, topiramate, and an active metabolite of oxcarbazepine, 10, 11-dihydro-10-hydroxycarbamazepine, in human plasma by high-performance liquid chromatography-tandem mass spectrometry using the positive/negative ion-switching ionization mode. The method was assessed for accuracy, precision, linearity, recovery, and matrix effects according to the criteria of the U.S. Food and Drug Administration Bioanalytical Method Validation Guidelines for Industry for Bioanalytical Methods. The lower limit of quantification was determined to be 0.001-25 µg/mL for each analyte. The intra- and inter-day precision values had <14.6% coefficients of variation, and the accuracy ranged from 85.3% to 113% at the three levels of quality control. In addition, this method was successfully applied to therapeutic drug monitoring of ASMs in patients with epilepsy. This method allows for simple preparation, accurate quantification, and the determination of different ASMs without requiring analytical method switching, making it particularly suitable for therapeutic drug monitoring in busy clinical and hospital laboratory settings.

Determination of Antiepileptics in Biological Samples-A Review

Epilepsy remains a disease that affects many people around the world. With the development of new drugs to treat this condition, the importance of therapeutic drug monitoring continues to rise and remains a challenge for the medical community. This review article explores recent advances in the detection of antiepileptic drugs across various sample types commonly used for drug monitoring, with a focus on their applications and impact. Some of these new methods have proven to be simpler, greener, and faster, making them easier to apply in the context of therapeutic drug monitoring. Additionally, besides the classic use of blood and its derivatives, there has been significant research into the application of alternative matrices due to their ease of sample collection and capacity to reflect drug behavior in blood. These advances have contributed to increasing the efficacy of therapeutic drug monitoring while enhancing its accessibility to the population.

An automated streamlined method for the therapeutic drug monitoring of digoxin based on the online-solid-phase extraction liquid chromatography tandem high-resolution mass spectrometry

RATIONALE

Digoxin is widely used in the clinical treatment of cardiovascular diseases. However, due to its extremely narrow therapeutic window, therapeutic drug monitoring (TDM) is vitally important. In consideration of the time-consuming and labor-intensive nature of the traditional techniques, an automated and efficient method was required for the clinical individualized TDM of digoxin.

METHODS

An online solid-phase extraction liquid chromatography tandem high-resolution mass spectrometry (online-SPE-LC-HRMS) method was developed and applied for the determination of digoxin in plasma. The online SPE-LC steps included pretreatment and separation of plasma samples that were carried out using a Waters Oasis HLB cartridge and XBridge Shield RP18 column, respectively. A high-resolution Q Orbitrap mass spectrometer with targeted-selected ion monitoring in negative scan mode was applied to monitor formate-adduct ions [M + HCOO]^- m/z 825.42781 for digoxin.

RESULTS

Linearity was shown over the range 0.1-10 ng mL^-1 for digoxin with correlation coefficients of R²  > 0.999. The lower limit of quantitation (LLOQ) for digoxin was 0.1 ng mL^-1 . Extraction recoveries ranged from 82.61% to 94.28% for digoxin. The intra- and inter-day precision values were < 5.53% with accuracy ranging from 84.97% to 96.75%. The total running time was 10 min for each sample.

CONCLUSION

The established method displayed satisfactory recoveries, accuracy, precision, and stability, and successfully applied on the TDM of digoxin. This automated streamlined method provides a powerful tool to guide the individualized administration of digoxin, which is significant for the practice of precision medicine.

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.