Monitoring Stability and Impurity Products of GLP-1 Agonists Using a Novel Single Quadrupole LC/MS

Significance of the topic

Glucagon-like peptide-1 receptor agonists such as semaglutide and tirzepatide are essential therapies for type 2 diabetes and obesity management by enhancing insulin secretion and metabolic control. Monitoring their stability and impurity profiles ensures efficacy and safety.

Objectives and Study Overview

This study evaluates the stability and degradation products of semaglutide and tirzepatide under varying pH and storage conditions using a novel single quadrupole LC/MS platform.

Methodology and Instrumentation

A stock solution of each peptide was prepared and diluted in pH 5, 7, and 9 buffers then stored at 5 °C. Samples were analyzed over seven days without additional cleanup using an Agilent 1290 Infinity II Bio LC coupled to a Pro iQ Plus single quadrupole mass detector. Chromatographic separation employed a ZORBAX RRHD StableBond C18 column with a water/acetonitrile gradient containing 0.1% formic acid. Mass spectra were acquired in positive mode across m/z 500–2500.

Main Results and Discussion

Tirzepatide and semaglutide both exhibited oxidation and dioxidation impurities detectable at levels below 2% relative area. Deconvoluted masses aligned within ±0.3 Da of theoretical values. Kinetic profiling revealed tirzepatide is most susceptible to oxidation at pH 5 while semaglutide degrades more at pH 9.

Practical Benefits and Applications

The sensitive, user-friendly LC/MS method is suitable for routine quality control and stability testing in pharmaceutical laboratories.

Future Trends and Potential Applications

Advancements may include higher-resolution mass analyzers, real-time degradation monitoring, and integration with automated workflows for peptide therapeutics development and regulatory compliance.

Conclusion

The Agilent Pro iQ Plus single quadrupole LC/MS system demonstrates robust performance for low-level impurity detection in GLP-1 agonists, supporting stability studies and quality assurance.

References

• Vilsbøll T, Christensen M, Junker AE, Knop FK, Gluud LL. Effects of Glucagon-Like Peptide-1 Receptor Agonists on Weight Loss: Systematic Review and Meta-Analyses of Randomised Controlled Trials. BMJ. 2012;344:d7771.
• U.S. Food and Drug Administration, Center for Drug Evaluation Research. ANDAs for Certain Highly Purified Synthetic Peptide Drug Products That Refer to Listed Drugs for rDNA Origin; Guidance for Industry. 2021.