Two USP Analyses of Pregabalin Using One LC

Importance of the Topic

Pregabalin is a leading pharmaceutical for neuropathic pain and epilepsy with multibillion dollar sales. Quality control of its content and enantiomeric purity is critical to ensure efficacy and safety. Adopting streamlined analytical workflows reduces turnaround times and solvent consumption while maintaining compliance with pharmacopeial standards.

Objectives and Study Overview

This application note demonstrates the integration of two USP monograph HPLC methods for pregabalin assay and enantiomeric purity on a single LC system with automated column switching. It also details the transfer of these methods to UHPLC conditions in line with USP chapter 621 to achieve significant time and solvent savings.

Methodology and Instrumentation

• Instrumentation used
  
  • Agilent 1260 Infinity II Flexible Pump
  • Agilent 1260 Infinity II Multisampler with thermostat
  • Agilent 1260 Infinity II Multicolumn Thermostat with 4 position 10 port column selection valve
  • Agilent 1260 Infinity II Diode Array Detector HS with Max Light cartridge cell
  • Columns
    
    • Agilent ZORBAX Eclipse Plus C18 4.6×250 mm 5 µm
    • Agilent ZORBAX Eclipse Plus C18 2.1×100 mm 1.8 µm
    • Agilent InfinityLab Poroshell 120 EC C18 2.1×100 mm 2.7 µm
  • Software Agilent OpenLab CDS Version 2.4
• Chemicals and Standards
  
  • LC grade acetonitrile acetone water
  • Pregabalin and related compound A reference standards
  • Marfeys reagent and sodium bicarbonate
• Method conditions
  
  • USP assay method isocratic water acetonitrile 95:5 detection at 205 nm
  • UHPLC transfer uses same mobile phase on sub 2 µm or superficially porous column with adjusted flow and injection volume
  • Enantiomeric purity method uses Marfeys derivatization with triethylamine water phosphoric acid acetonitrile mobile phase at 340 nm
  • UHPLC options include 1.8 µm C18 or 2.7 µm Poroshell column with elevated pressure

Main Results and Discussion

Both USP methods ran automatically on one LC system via column switching with no manual intervention. System suitability criteria were met for retention time precision tailing and resolution. The UHPLC assay transfer achieved 80 percent time and 88 percent solvent savings while maintaining peak quality and precision. Enantiomeric purity UHPLC methods delivered 71 to 77 percent time savings and 90 to 91 percent solvent reductions with resolution above USP thresholds in both sub 2 micron and superficially porous column formats.

Benefits and Practical Applications

• Automated column selection streamlines dual method workflows
• UHPLC transfer reduces analysis time and solvent use lowering operational costs
• High precision and compliance with USP standards ensure robust quality control

Future Trends and Potential Applications

Adoption of fully integrated UHPLC platforms with automated column switching will enhance throughput for pharmaceutical QC. Further advances in column technology and green solvents promise additional sustainability and efficiency gains. The approach can extend to other chiral and impurity assays in regulated industries.

Conclusion

Implementing both pregabalin assay and enantiomeric purity methods on a single Agilent 1260 Infinity II Prime LC system with automated column switching successfully meets USP requirements. Transferring to UHPLC provides substantial time and solvent savings while preserving analytical performance, offering a cost effective and scalable solution for pharmaceutical quality control.

Reference

1. Statista Top 10 Pharmaceutical Products by Global Sales 2018
2. Stahl SM et al The Diverse Therapeutic Actions of Pregabalin Trends Pharmacol Sci 2013 34 6 332 339
3. Taylor CP et al Pharmacology and Mechanism of Action of Pregabalin Epilepsy Res 2007 73 137 150
4. United States Pharmacopeia Monograph on Pregabalin to be official 1 Nov 2020