Comparison of Biotage Extrahera vs. Manual Sample Processing Using a Vacuum Manifold - Extraction of NSAIDs from Plasma

Significance of the Topic

Efficient and reproducible extraction of non-steroidal anti-inflammatory drugs (NSAIDs) from plasma is critical for bioanalytical studies, therapeutic drug monitoring and quality control in pharmaceutical research. Supported liquid extraction (SLE) offers a simple, high-throughput sample preparation technique that minimizes matrix effects and operator variability.

Objectives and Study Overview

This study compares an automated SLE workflow using the Biotage Extrahera™ platform with a conventional manual vacuum-manifold method. Target analytes—Sulindac, Ketoprofen (internal standard) and Indomethacin—were extracted from pooled human plasma fortified at 25 ng/mL to evaluate recovery, precision and overall method performance.

Methodology and Used Instrumentation

Sample Preparation Procedure:

• Pooled plasma was diluted 1:1 (v/v) with 1 % formic acid to achieve pH 3.2 and spiked with analytes.
• 400 µL of pre-treated sample was loaded onto ISOLUTE SLE+ 96-well plates, allowing 5 minutes absorption.
• Analytes were eluted with two 0.9 mL aliquots of methyl tertiary-butyl ether (MTBE).
• Extracts were collected under gravity, followed by a positive-pressure (Extrahera) or vacuum (manual) pulse to recover residual solvent.
• Samples were evaporated to dryness at 37 °C in a TurboVap 96 and reconstituted in 200 µL of 60:40 water/methanol, then mixed for 10 minutes.

Instrumentation:

• Automated workstation: Biotage Extrahera™ or manual vacuum manifold
• Evaporation: TurboVap 96 at 37 °C
• LC: Waters Alliance 2795 with ACE Excel 2 C18-AR column (50 × 2.1 mm), mobile phase 50:50 0.1 % formic acid/acetonitrile, flow rate 0.25 mL/min, injection volume 25 µL
• MS: Waters Quattro Ultima Pt in MRM mode; transitions 358.1→139.0 (Indomethacin), 357.1→233.1 (Sulindac), 255.1→209.1 (Ketoprofen)

Main Results and Discussion

Comparison of automated versus manual extraction demonstrated:

• Sulindac peak area increased by 7.8 % (22 847→24 622) with %RSD reduced from 6.43 % to 4.01 % (37.6 % improvement).
• Indomethacin peak area increased by 23.0 % (27 965→34 395) with %RSD reduced from 8.56 % to 5.46 % (36.2 % improvement).
• Internal standard (Ketoprofen) peak area rose by 7.7 %.
• Overall average peak area gain for both analytes was 15.4 %, indicating enhanced recovery.

Benefits and Practical Applications

Automation with the Biotage Extrahera™ platform delivers higher extraction efficiency, improved precision and reduced variability compared to manual methods. This translates into more reliable quantitative data, increased throughput and decreased labor requirements in bioanalytical laboratories.

Future Trends and Potential Applications

Advances in high-throughput sample preparation will drive integration of SLE with online LC-MS workflows, miniaturized plate formats and multiplexed automation systems. Extending this approach to diverse compound classes and complex matrices will further streamline bioanalysis and support real-time quality control.

Conclusion

The automated SLE method using Biotage Extrahera™ significantly improves recovery and reproducibility for NSAID extraction from plasma, outperforming manual vacuum-manifold protocols. This robust workflow enhances laboratory efficiency and analytical confidence in bioanalytical applications.