Scaling of a USP Assay for Quetiapine Fumarate Across Different Liquid Chromatographic Systems

Importance of the Topic

Scaling compendial assays to modern chromatographic systems is critical for pharmaceutical laboratories to enhance throughput,
reduce solvent consumption and costs while maintaining regulatory compliance and chromatographic performance.

Objectives and Study Overview

The study demonstrates the scaling of the USP monograph assay for quetiapine fumarate from legacy HPLC conditions to smaller particle pillars using the Waters Column Calculator.
The scaled methods were evaluated across three liquid chromatography platforms to assess run time, solvent usage, system suitability and assay consistency.

Methodology and Instrumentation

Quetiapine fumarate reference standards and samples were prepared in isocratic mobile phase (methanol, acetonitrile and phosphate buffer pH 6.5).
Key analytical conditions were:

• Temperature 25°C, sample temperature 4°C, detection at 230 nm with 4.8 nm bandwidth
• Standards at 1.0 mg/mL (system suitability) and 0.08 mg/mL (standard/sample)

Applied instrumentation:

• Alliance e2695 HPLC System with 5 µm XBridge BEH C8 column (4.6×250 mm)
• ACQUITY Arc UHPLC System with 3.5 µm XBridge BEH C8 column (3.0×150 mm)
• ACQUITY UPLC H-Class PLUS System with 1.7 µm BEH C8 column (2.1×75 mm)
• Waters Column Calculator for L/dp based scaling and Empower 3 Software for data management

Main Results and Discussion

Scaling to a 3.5 µm, 3.0×150 mm column on the Arc UHPLC system reduced run time by 53% (15 to 7 min) and solvent use by 66% while meeting USP suitability criteria (resolution ≥1.5, tailing ≤2.0, RSD ≤2.0%).
Further scaling to a 1.7 µm, 2.1×75 mm column on the UPLC system cut run time by 80% (to 3 min) and solvent consumption by 88%.
All methods exhibited comparable retention, peak shape and quantitative consistency for quetiapine fumarate across platforms. The discussion highlighted the importance of controlling extra-column dispersion and dwell volume for small-diameter isocratic separations.

Benefits and Practical Applications

Key advantages of the scaled methods include:

• Substantial throughput improvement enabling higher sample capacity
• Significant solvent and cost reduction per analysis
• Preservation or enhancement of chromatographic performance
• Regulatory compliance through consistent system suitability results
• Flexibility to transfer methods across diverse LC platforms

Future Trends and Potential Applications

Anticipated developments include adoption of microflow and nanoflow systems, integration with mass spectrometry for enhanced specificity, advanced modeling for predictive method scaling, and further miniaturization to support green analytical chemistry initiatives.

Conclusion

The application note confirms that USP compendial assays can be effectively scaled to modern sub-2 µm columns and UPLC/UHPLC platforms using the Waters Column Calculator.
These adaptations deliver dramatic improvements in analysis speed, solvent savings and operational efficiency while maintaining regulatory acceptance criteria.

Reference

• United States Pharmacopeia General Chapter 621 Chromatography. USP 40–NF35 S1, 2017.
• USP Monograph Quetiapine Fumarate. USP 40–NF35 S1, p. 5939, 2017.
• Snyder LR, Kirkland JJ, Dolan JW. Introduction to Liquid Chromatography. Wiley, 2010.
• Snyder LR et al. Impact of dwell volume and extra-column dispersion. Wiley, 2010, p. 112.
• Hong P, McConville PR. Dwell Volume and Extra-Column Volume: Impact on Method Transfer. Waters Corporation, 2016.