Therapeutic drug monitoring of Antiepileptic drugs in serum: a fully automated approach

Significance of Antiepileptic Drug Monitoring

Epilepsy is a chronic neurological disorder with unpredictable seizure patterns. Variability in pharmacokinetics among patients makes therapeutic drug monitoring (TDM) of antiepileptic drugs (AEDs) essential for optimizing treatment efficacy and safety. High-precision analytical techniques such as liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) are required to accurately quantify AED serum levels.

Objectives and Overview of the Study

This work aimed to develop a fully automated workflow for quantifying 26 AEDs in human serum. By integrating an automated sample preparation unit with LC-MS/MS, the study sought to eliminate manual extraction and protein precipitation steps, thereby enhancing throughput, reproducibility, and data quality in routine TDM.

Methods and Instrumentation

Sample preparation was performed using the CLAM-2000 automatic preparation unit maintained at 8 °C. Serum samples, calibrators, and internal standards were loaded onto the CLAM-2000, which executed protein precipitation, extraction, filtration, and transfer to the LC system without human intervention. Chromatographic separation and mass spectrometric detection were carried out on a Shimadzu Nexera X2 LC system coupled to an LCMS-8060 triple quadrupole mass spectrometer. The ClinMass® TDM Kit provided standardized calibrators and internal standard mixes. Multiple reaction monitoring (MRM) transitions were optimized for each AED to ensure selective quantitation.

Main Results and Discussion

The fully automated workflow achieved a throughput of one complete AED quantitation every six minutes. Method comparison using Passing-Bablok regression demonstrated excellent agreement between automated and traditional manual sample preparation across 20 spiked serum samples. Calibration curves for all analytes exhibited linearity within 85 %–115 % accuracy. Intra- and inter-day precision studies using reference serum controls yielded coefficient-of-variation (CV) values within accepted analytical ranges. Bias remained below 15 % for all compounds, meeting clinical TDM requirements.

Benefits and Practical Applications

• Complete elimination of manual sample handling reduces operator workload and variability.
• Improved throughput supports high-volume TDM in clinical and research laboratories.
• Lower reagent consumption decreases per-assay cost.
• Automated documentation enhances traceability and regulatory compliance.

Future Trends and Potential Applications

Further integration of automated sample preparation with laboratory information systems and artificial intelligence–driven data review could streamline TDM workflows. Expansion of automated platforms to cover additional therapeutic drug classes and biomarkers will support personalized medicine. Miniaturized and point-of-care LC-MS/MS devices may bring high-precision monitoring directly to clinical settings.

Conclusion

This study demonstrates that a fully automated LC-MS/MS method for AED quantitation in serum is feasible and robust. Automation enhances analytical performance, reduces human error, and lowers operational costs, making it a compelling approach for routine therapeutic drug monitoring.