Analytical Quality by Design Based Method Development for the Analysis of Valsartan and Nitrosamines Impurities Using UPLC-MS

Importance of the topic

Genotoxic nitrosamines in pharmaceutical products pose critical health risks due to their DNA-reactive properties and regulatory limits require sensitive, robust analytical methods to ensure patient safety.

Objectives and study overview

This work aimed to apply an Analytical Quality by Design (AQbD) strategy using automated software tools to develop a high-performance UPLC-MS method for simultaneous analysis of valsartan and six nitrosamine impurities.

Methodology and instrumentation

• Analytical Quality by Design: systematic DOE screening of gradient time, methanol proportion, and column temperature to define the Method Operable Design Region (MODR).
• Software integration: DryLab4 for modeling and Empower 3 CDS for automated method generation and data processing.
• Chromatographic system: ACQUITY UPLC H-Class with Quaternary Solvent Manager, Column Manager, PDA detector, and QDa Mass Detector.
• Column and mobile phase: HSS T3 column (2.1×100 mm, 1.8 µm), 0.1% formic acid in water and methanol gradient (2–98% B over 25 min), flow rate 0.4 mL/min, column temperature 33 °C.
• Mass spectrometry: ESI+ mode, m/z range 100–500 Da, capillary voltage 0.8 kV, source temperature 600 °C.

Main results and discussion

• Resolution mapping identified a robust design space achieving baseline separation of valsartan and six nitrosamines with critical pair resolution >1.5.
• Robustness assessment predicted resolution >16 under working point conditions and highlighted flow rate and gradient time as critical parameters.
• Method verification over 15 injections across three days demonstrated excellent reproducibility with %RSD <1% for retention time, peak area, and resolution.

Benefits and practical applications

• Fully automated AQbD workflow reduces development time and transcription errors.
• Fit-for-purpose method meets regulatory flexibility within the MODR without further approval.
• High reproducibility and robustness support routine QC of valsartan and nitrosamine impurities.
• Use of QDa Mass Detector ensures reliable peak tracking and identification.

Future trends and potential applications

• Integration of AI-driven optimization and predictive modeling for further method refinement.
• Extension of AQbD strategies to other pharmaceutical compounds and impurity profiles.
• Advancements in real-time monitoring and in-line detection using novel detectors.
• Broader adoption of automated CDS-Lab software ecosystems for comprehensive lifecycle method management.

Conclusion

The combined AQbD approach with DryLab and Empower software on an ACQUITY UPLC H-Class system provides a robust, reproducible UPLC-MS method for valsartan and nitrosamine impurities, ensuring regulatory compliance and efficient routine analysis.

References

1. ICH S2 (R1) Genotoxicity Testing and Data Interpretation for Pharmaceuticals Intended for Human Use, 2012.
2. ICH Q8(R2) Pharmaceutical Development, 2009.
3. Reid GL et al. Analytical Quality by Design (AQbD) in Pharmaceutical Development, Am Pharm Rev, 2013.
4. Chatfield MA et al. Evaluating Progress in Analytical Quality by Design, 2017.
5. Alkhateeb FL, Rainville P. Software-Assisted AQbD for UPLC-MS Analysis of Formoterol and Budesonide, Waters, 2019.
6. Fekete S, Molnár I. Software-Assisted Method Development in HPLC, World Scientific, 2018.