Straightforward transfer of an EP method for impurity analysis of chlorhexidine from an Agilent 1260 Infinity LC system to a Vanquish Core HPLC system

Importance of the Topic

Chlorhexidine is an essential antiseptic and disinfectant employed in pharmaceuticals and hygiene products. Impurity profiling by HPLC ensures safety and efficacy in quality control.

Reliable transfer of compendial HPLC methods between different instrument platforms is critical for inter-laboratory consistency, workload distribution, and replacement of legacy systems.

Objectives and Study Overview

This study demonstrates the direct transfer of an European Pharmacopoeia monograph method for chlorhexidine impurity analysis from an Agilent 1260 Infinity LC system to a Thermo Fisher Vanquish Core HPLC system.

Key goals include:

• Maintaining equivalent chromatographic performance
• Utilizing gradient delay volume (GDV) adjustments to fine-tune retention times
• Ensuring compliance with system suitability criteria

Methodology

Sample preparation and reagents followed the EP monograph: chlorhexidine reference standard dissolved in mobile phase. The gradient, column temperature, flow rate, and detection settings were kept identical to the original method during transfer.

Instrumentation

• Source system: Agilent 1260 Infinity LC with quaternary pump, autosampler, thermally controlled column compartment, and VWD detector
• Target system: Thermo Fisher Vanquish Core HPLC with quaternary pump, split sampler CT, column compartment C with passive pre-heater, and VWD C detector
• Column: Thermo Scientific Hypersil GOLD C18, 4.6 × 250 mm, 5 µm, end-capped

Main Results and Discussion

Both systems generated virtually identical chromatograms with comparable peak areas, resolutions, and relative retention times under default settings. System suitability criteria (resolution ≥ 3 for impurity pair L/G and peak-to-valley ≥ 2 for impurity B) were easily met on both platforms.

A small systematic shift in absolute retention times (0.02–0.22 min earlier on Vanquish Core) was attributed to differences in GDV. By adjusting the autosampler idle volume from 25 µL to 200 µL, retention time deviations were reduced, achieving closer alignment without altering the gradient profile.

Benefits and Practical Applications

• Seamless, compliant transfer of compendial HPLC methods with minimal revalidation
• GDV tuning enables precise retention time matching across instruments
• Enhanced laboratory flexibility for workload sharing and instrumentation upgrades

Future Trends and Potential Applications

Advances may include automated GDV optimization, digital method transfer protocols, and expanded instrument–agnostic software tools. Wider application to USP methods and novel stationary phases will further streamline cross-platform transfers.

Conclusion

The EP monograph HPLC method for chlorhexidine impurity analysis was successfully transferred from an Agilent 1260 Infinity to a Vanquish Core system. The adaptable GDV controls of the Vanquish Core system proved essential for fine-tuning retention times, ensuring equivalent chromatographic results and compliance with compendial requirements.

References

1. Swartz ME, Krull I. Analytical method transfer. LCGC North America 2006;24(11):1204–1214.
2. Paul C, Grübner M, et al. An instrument parameter guide for (U)HPLC method transfer. Thermo Fisher White Paper 72711, 2018.
3. Grübner M. Transfer of an EP method for mebendazole from Waters to Vanquish. Thermo Fisher AN72939, 2019.
4. Grübner M, Paul C, Steiner F. Transfer of USP acetaminophen assay between LC systems. Thermo Fisher AN72717, 2018.
5. European Pharmacopoeia monograph 0658: Chlorhexidine digluconate solution, Ph Eur 10.0.
6. World Health Organization. Model List of Essential Medicines. 21st ed, 2019.
7. United States Pharmacopeia USP42–NF37. Chlorhexidine gluconate solution, 2019.
8. Ph. Eur. reference standard leaflet: Chlorhexidine CRS batch 2.
9. Franz H, Wachinger T, Schmidt C. DE102015112900B4: Method for transferring LC methods, 2015.
10. Thermo Fisher Scientific. Vanquish Core HPLC system specifications, 2020.