EMPLOYING MODERN LIQUID CHROMATOGRAPHY TECHNOLOGY TO SCALE A USP GRADIENT METHOD ON A SINGLE LIQUID CHROMATOGRAPHIC SYSTEM

Significance of the Topic

The modernization of chromatographic methods is critical for pharmaceutical analysis as it enhances throughput, reduces solvent consumption, and maintains regulatory compliance through consistent impurity profiling of active pharmaceutical ingredients like quetiapine fumarate.

Objectives and Study Overview

This study aimed to adapt the USP gradient method for quetiapine impurities onto a single LC system by scaling from a traditional HPLC configuration to columns with smaller particles (2.5 μm and 1.7 μm). The goal was to assess chromatographic integrity while decreasing run times and solvent usage.

Methodology and Instrumentation

• Instrumentation Used: Waters ACQUITY Arc UHPLC System with CH-30A active solvent preheater and 2998 PDA detector set at 250 nm, 4.8 nm resolution, column temperature 45 °C, sample temperature 4 °C.
• Columns: XBridge BEH C8, 3.5 μm, 4.6×150 mm; XBridge BEH C8 XP, 2.5 μm, 3.0×100 mm; BEH C8, 1.7 μm, 2.1×75 mm.
• Mobile Phases: Solution A (25:75 acetonitrile:ammonium acetate buffer, pH ≥ 9.2), Solution B (acetonitrile).
• Scaling Approach: Waters Columns Calculator to maintain L/dp ratio and adjust flow, injection volume, and gradient timing.
• Gradient Programs adjusted for each column to preserve selectivity.

Main Results and Discussion

Scaling the method led to substantial reductions in analysis time and solvent consumption:

• 2.5 μm column: 51 % shorter runtime and 71 % solvent savings compared to the original method.
• 1.7 μm column: 75 % shorter runtime and 89 % solvent savings.

Chromatographic performance metrics including resolution between peak 1 and 2 (10.8–13.3), tailing factors (0.95–1.0), and retention time and area RSDs (< 1.3 %) met USP requirements. A slight resolution decrease on UPLC was attributed to system dispersion but remained above the minimum threshold of 1.5.

Benefits and Practical Applications

• Increased laboratory efficiency and throughput.
• Reduced operational costs through lower solvent use.
• Compliance with compendial limits for impurity separation.
• Scalable approach applicable to other gradient methods.

Future Trends and Opportunities

Further method miniaturization, integration with real-time process monitoring, and use of automated scaling tools represent key directions. Advances in column technology and AI-driven optimization may enable rapid method transfer across diverse platforms.

Conclusion

• Gradient scaling on the ACQUITY Arc UHPLC System is feasible without compromising analytical performance.
• Waters Columns Calculator simplifies the transfer process.
• Smaller particle columns deliver significant time and solvent savings while maintaining resolution and precision.

References

1. Fountain K. Transferring Compendial HPLC Methods to UPLC Technology for Routine Generic Drug Analysis. Waters Application Note.
2. United States Pharmacopeia and National Formulary. Official Monographs, Quetiapine Fumarate USP 40 NF35 S1. 2017.
3. Neue UD, McCabe D, Vijaya R, Pappa H, DeMuth J. Transfer of HPLC Procedures to Suitable Columns of Reduced Dimensions. Pharmacopeial Forum. 2009;35(6):1622.
4. Waters Columns Calculator Online Help. Version 2.0.
5. Hong P, McConville P. Dwell Volume and Extra-Column Volume: What Are They and How do They Impact Method Transfer. Waters White Paper. 720005723EN. 2016.