Application Note Modernized Impurity Analysis of the Kinase Inhibitor Imatinib by High-Resolution LC With MS-Compatible Mobile Phases

Significance of the Topic

The impurity profiling of kinase inhibitors such as imatinib is critical for ensuring drug safety, efficacy, and regulatory compliance. High-resolution methods that combine rapid separation with structural confirmation are essential for modern pharmaceutical quality control and research.

Objectives and Study Overview

This study aimed to modernize the European Pharmacopeia HPLC method for imatinib impurity analysis by developing a UPLC protocol with mass spectrometry compatibility. Key goals included shortening analysis time, improving resolution of nine related impurities, and enabling MS and MS/MS identification.

Methodology and Instrumentation

Standard solutions of imatinib and nine impurities were prepared in methanol/acetonitrile and analyzed using UPLC with UV and MS detection. Instrumentation included:

• UPLC System: ACQUITY UPLC I-Class
• Columns: HSS C18 (2.1×100 mm, 1.8 μm) and Premier CSH Phenyl-Hexyl (2.1×100 mm, 1.7 μm)
• Mobile Phases: 0.1% formic acid with 10 mM ammonium formate (A) and 0.1% formic acid in acetonitrile (B)
• MS System: Vion IMS QTof with ESI positive mode and UNIFI v1.8 for data acquisition

Main Results and Discussion

Initial adaptation of the EP method to UPLC with C18 achieved rapid elution but suffered co-elution of impurity pairs. Switching to the CSH Phenyl-Hexyl column and optimizing the gradient improved selectivity for N-heterocyclic structures, enabling baseline separation of all nine impurities within six minutes. Extracted ion chromatograms and TOF MS/MS fragmentation spectra confirmed peak identities and structural assignments.

Benefits and Practical Applications

• Dramatically reduced run time for comprehensive impurity profiling
• Enhanced resolution of closely eluting impurities
• MS-compatible mobile phases for structural confirmation and unknown peak identification
• Applicability to QC workflows and extension to other kinase inhibitors

Future Trends and Applications

Advances may include low-level impurity detection, integration with high-throughput screening, expansion to other drug classes, and enhanced data analysis using AI-driven workflows.

Conclusion

The developed UPLC-MS method using a charged-surface phenyl phase offers fast, sensitive, and high-resolution impurity analysis for imatinib. This modernized approach supports regulatory requirements and accelerates drug development and quality control.

References

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2. Bhullar KS, et al. Kinase-Targeted Cancer Therapies: Progress, Challenges and Future Directions. Mol Cancer. 2018;17:48.
3. Roskoski R Jr. Properties of FDA-Approved Small Molecule Protein Kinase Inhibitors: A 2021 Update. Pharmacol Res. 2021;165:105463.