Analytical method development, identification, and characterization of stress degradation products of idelalisib by ultrahigh‐performance liquid chromatography with photodiode array and ultrahigh‐performance liquid chromatography with electrospray ionization quadrupole time‐of‐flight mass spectrometry studies

As per International Council for Harmonization (ICH) drug stability test guideline Q1A(R2), inherent stability characteristics of a drug should be studied. This work was designed to investigate inherent degradation characteristics of the drug idelalisib under ICH prescribed stress conditions, identify its degradation products, and postulate their corresponding degradation pathways.