Size-exclusion LC-UV/HRMS based method for the analysis of aggregates in synthetic GLP-1 analog liraglutide and evaluation of excipient impact on aggregation

Peptide aggregation is one of the key challenges associated with the development of therapeutic peptides. Peptide and protein aggregates are considered as one of the most important critical quality attributes (CQA). Therapeutic liraglutide (LGT) is proteinaceous in nature, and aggregation can be triggered by various environmental stress condition. Therefore, it is essential to separate and identify aggregation states of such drugs. In this study, we have established size exclusion chromatography-liquid chromatography-ultraviolet/high resolution mass spectrometry (SEC-LC-UV/HRMS) method to separate and identify the stress induced LGT aggregates. LGT samples were subjected to photolytic, thermal, freeze thaw and shaking stress conditions. Additionally, LGT solution was incubated with surfactant and excipient that are commonly used in peptide formulation, to evaluate their impact on aggregation level and physicochemical stability over time. The developed SEC method was also validated for specificity, accuracy, precision and linearity. The results of this study will be useful for investigators to monitor LGT aggregates during product development.