A Validated, Stability‐Indicating HPLC Method for the Simultaneous Determination of Five Related Substances in Liraglutide Drug Substance

Liraglutide, an analog of glucagon-like peptide-1, is a treatment for the management of type 2 diabetes mellitus and obesity. In this study, we developed and validated a straightforward, sensitive, and reproducible gradient reverse-phase high-performance liquid chromatographic method for the separation and quantification of related substances in liraglutide drug substance. A C8 column was employed as the chromatographic column, with a mobile phase comprising phosphate buffer solution and acetonitrile. Under optimized chromatographic conditions, five specific impurities within liraglutide could be efficiently separated simultaneously. The resolution between main peak and each impurity was greater than 1.0, and the tailing factor of the main peak was less than 1.0. This method exhibited high sensitivity and enabled quantitative determination of both liraglutide and each impurity, thereby effectively ensuring the quality control of liraglutide products. The developed method is validated in accordance with the guidelines set by the International Conference on Harmonization regarding specificity, linearity, limit of detection, limit of quantification, accuracy, precision, and robustness.