Simultaneous Analysis of Antiarrhythmic Drugs in Human Blood Plasma Using the Fully Automated Sample Preparation LC/MS/MS System

Importance of the topic

Precise monitoring of antiarrhythmic drug levels in human plasma is critical due to narrow therapeutic windows and variable patient response. Therapeutic drug monitoring supports individualized dosing through pharmacokinetic and pharmacodynamic analysis. Automated, high-throughput workflows reduce manual errors and improve clinical laboratory efficiency.

Study objectives and overview

This study presents a fully automated workflow for simultaneous quantification of six antiarrhythmic drugs and key metabolites in human plasma. By integrating the CLAM-2000 automated sample preparation unit with a Nexera UHPLC system and LCMS-8060 mass spectrometer, the authors aimed to streamline sample handling and accelerate analysis while maintaining robust analytical performance.

Methodology and instrumentation

Human plasma samples underwent automated deproteinization by acetonitrile addition and centrifugal filtration within the CLAM-2000 unit. Sample preparation ran in parallel with LC/MS/MS analysis, achieving a 7-minute cycle per sample. Chromatography used a Shimadzu GLC Mastro C18 column (50 × 2.1 mm, 3 µm) and a gradient of 0.1% formic acid in water and methanol at 0.4 mL/min. Electrospray ionization in positive mode monitored multiple reaction monitoring transitions for each analyte. Key instrumentation:

• CLAM-2000 automated sample preparation unit
• Nexera UHPLC system
• LCMS-8060 triple quadrupole mass spectrometer
• Shimadzu GLC Mastro C18 column

Key results and discussion

Calibration curves over ranges of 50–3000 ng/mL demonstrated excellent linearity (R² > 0.998) for all compounds. Accuracy was within ±15% and precision below 15% RSD at the lower limit of quantification, low, medium, and high QC levels. No significant carryover was detected after the highest calibration standard. Comparative analysis against manual protein precipitation showed strong agreement (R² ≥ 0.95) and average automated/manual concentration ratios of 92–110%, confirming equivalence in quantitative results.

Benefits and practical applications

• Significantly reduced hands-on time and labor
• High throughput with 7-minute analysis cycles
• Quantitative performance matching manual methods
• Minimized carryover and human error

Future trends and possibilities

Future developments may include integration with laboratory information management systems, expansion to broader drug and metabolite panels, and application of AI-driven optimization for method parameters. Enhanced automation could support real-time therapeutic monitoring and enable precision medicine initiatives.

Conclusion

The fully automated LC/MS/MS system delivers reliable, rapid quantification of multiple antiarrhythmic drugs and metabolites in human plasma, matching the accuracy and precision of manual workflows. Its implementation optimizes therapeutic drug monitoring and overall laboratory productivity.

Reference

• Guidance for Industry: Bioanalytical Method Validation, US FDA, 2001
• Guideline on Bioanalytical Method Validation in Pharmaceutical Development, Japan MHLW, 2013