HPLC to UHPLC Transfer of USP Method for Amlodipine Besylate Using the Agilent 1290 Infinity II LC

Importance of the Topic

The availability of generic amlodipine besylate formulations demands robust, efficient analytical methods for quality control. Updating USP compendial HPLC assays to modern UHPLC platforms can significantly reduce analysis time and solvent consumption while maintaining compliance with official system suitability criteria. These improvements enhance laboratory throughput and resource utilization in pharmaceutical analysis.

Objectives and Study Overview

This study presents the transfer of a USP monograph HPLC method for the assay of amlodipine besylate tablets to an Agilent 1290 Infinity II UHPLC system. The goal was to adjust column dimensions and operating parameters within USP allowed limits to avoid revalidation, then compare system suitability, precision, linearity, and analysis times between HPLC and UHPLC.

Applied Methodology

An isocratic reversed-phase method with UV detection at 237 nm was used for both HPLC and UHPLC. The original USP method employed a 3.9 × 150 mm, 5 µm column at 1.0 mL/min. For HPLC on the Agilent 1290 system, a 3 × 150 mm, 5 µm column was used at 0.6 mL/min with a 20 µL injection. The UHPLC method used a 2.1 × 50 mm, 1.8 µm column at 0.8 mL/min with a 10 µL injection. Flow rates were adjusted based on linear velocity criteria and particle size changes to keep L/dp ratios within USP guidelines. Sample preparation involved dissolving one tablet in mobile phase to yield 0.02 mg/mL amlodipine.

Instrumentation Used

• Agilent 1290 Infinity II High-Speed Pump (G7120A) with ultralow dispersion kit
• Agilent 1290 Infinity Multisampler (G7167B)
• Agilent 1290 Infinity II Multicolumn Thermostat (G7116B)
• Agilent 1290 Infinity II Diode Array Detector (G7117B)

Main Results and Discussion

Both HPLC and UHPLC methods met USP system suitability criteria: resolution ≥8.5, tailing factor ≤2.0, and RSD for peak area <1% for amlodipine. UHPLC achieved a reduction in retention time from 7.52 to 1.02 min and total run time from 23 to 3.1 min. Linear correlation coefficients (R²) of 0.99999 were obtained for both methods. UHPLC reduced mobile phase consumption per analysis from 13.8 mL to 2.5 mL. Method stability was demonstrated over 160 sequential UHPLC injections, with system pressure maintained between 730–740 bar and consistent peak areas and retention times.

Benefits and Practical Applications of the Method

• Up to 85% shorter analysis time, boosting sample throughput.
• Over 80% reduction in solvent usage, lowering operating costs and environmental impact.
• Maintained compliance with USP criteria without extensive revalidation.
• Enables rapid quality control of generic amlodipine formulations in pharmaceutical laboratories.

Future Trends and Potential Applications

High-efficiency UHPLC methods are expected to become standard in compendial analysis, driven by advances in column technologies such as core-shell and sub-2 µm particles. Further integration with mass spectrometry will expand impurity profiling. Automation and real-time process analytical technology (PAT) may leverage UHPLC for in-line monitoring. Coupling fast chromatographic data with AI-driven interpretation can enhance throughput and data quality in pharmaceutical quality assurance.

Conclusion

The successful transfer of the USP HPLC assay for amlodipine besylate to UHPLC on an Agilent 1290 Infinity II demonstrated significant gains in speed, solvent efficiency, and laboratory productivity while fully satisfying compendial performance requirements. This approach exemplifies the practical modernization of official methods for routine quality control.

Reference

• USP Monograph, Amlodipine Besylate Tablets, The United States Pharmacopeial Convention, February 1, 2011.
• First Supplement to USP 37–NF 32, The United States Pharmacopeial Convention, August 1, 2014.