Easy transfer of an EP method for chlorhexidine impurity analysis from a Shimadzu Nexera-i system to a Vanquish Core HPLC system

Importance of the Topic

Method transfers of official compendial liquid chromatography protocols among different HPLC systems are critical to maintain analytical consistency across research, quality control, and contract laboratories. The European Pharmacopoeia monograph for chlorhexidine impurity analysis represents a routine test in pharmaceutical and hygiene product manufacturing. Ensuring that the method performs equivalently after moving from an existing Shimadzu Nexera-i system to a modern Thermo Scientific Vanquish Core HPLC platform streamlines lab workflows and leverages enhanced hardware features.

Objectives and Study Overview

This study aimed to demonstrate a compliant, straightforward transfer of the EP chlorhexidine impurity method from a Shimadzu Nexera-i instrument to a Vanquish Core Quaternary HPLC system. Specific focus was placed on achieving equivalent chromatographic performance and utilising the Vanquish Core’s gradient delay volume (GDV) adjustment capabilities for fine-tuning retention times.

Methodology

The EP reference standard containing chlorhexidine and defined impurities was dissolved in mobile phase A (0.1 TFA in water/acetonitrile 80/20 v/v). Both systems used a Thermo Scientific Hypersil GOLD C18 column (4.6 x 250 mm, 5 µm, 175 Å) at 30 °C with a gradient from 0–30% B over 47 minutes at 1 mL/min. Detection was performed at 254 nm. Seven consecutive injections (7 µL each) were analysed to evaluate repeatability.

Used Instrumentation

• Shimadzu Nexera-i system with LC-2040C 3D MT pump, integrated quaternary solvent delivery, autosampler, column oven, and PDA detector.
• Thermo Scientific Vanquish Core Quaternary HPLC system with Core Pump C, Split Sampler CT, Column Compartment C, and Diode Array Detector.

Main Results and Discussion

Both instruments achieved equivalent separation of chlorhexidine and related impurities, meeting EP resolution and peak-to-valley criteria. The Vanquish Core system exhibited superior precision: retention time RSDs ≤0.05% versus ≤0.09% on Nexera-i, and peak area RSDs <0.5%. Initial absolute retention times on Vanquish Core were slightly earlier (average deviation 0.132 min). Adjusting the autosampler idle volume from 25 to 125 µL reduced this difference to 0.051 min, demonstrating effective GDV tuning. Further GDV increases are available via an optional method transfer kit.

Benefits and Practical Applications

• Maintains compendial compliance with minimal method revalidation by preserving all official parameters.
• Enhanced system precision and repeatability across instruments.
• Flexible GDV control enables rapid matching of retention profiles during method transfers.

Future Trends and Opportunities

Upcoming developments in HPLC technology—such as automated GDV optimization, digital twin simulations for method prediction, and AI-driven transfer protocols—will further simplify cross-platform method adaptation, reduce validation burden, and enhance laboratory efficiency.

Conclusion

The EP chlorhexidine impurity HPLC method was successfully transferred from a Shimadzu Nexera-i system to a Thermo Scientific Vanquish Core Quaternary HPLC platform. Equivalent chromatographic performance was achieved, with improved precision observed on the Vanquish Core. The system’s tunable GDV features facilitated precise retention time alignment, demonstrating a compliant and efficient strategy for compendial method migration.

Reference

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