Identification and characterization of unknown oxidation degradation products of Rimegepant by HPLC and triple...

Rimegepant is a calcitonin gene-related peptide receptor antagonist that has been licensed for migraine headache treatment in the United States, the European Union, the United Kingdom, Hong Kong, Australia, and Kuwait. The oxidation stress study of the Rimegepant drug substance revealed the presence of five impurities. Rimegepant degraded by 5% under the selected oxidation conditions, meeting regulatory expectations. Four out of five impurities are enhanced by more than 1%. This research aims to characterize these oxidation degradation products utilizing the triple quadrupole mass spectroscopic technique. The Rimegepant oxidation degradation products were identified using an optimized chromatographic method that relies on reverse-phase HPLC with PDA detection. This technique utilized a Waters Xbridge C18 column with an eluent mixture of acetonitrile and 0.1% formic acid in water. The oxidation products of Rimegepant have been effectively separated, with a resolution above 3.0. Triple quadrupole mass spectrometry analysis characterized the five degradation products, which showed three N-oxide impurities with masses m/z 566, m/z 550, and m/z 548, as well as two hydrolysis products with masses, m/z 218, m/z 290. These new impurities deserve special attention because the drug's potency and related impurity levels determine any pharmaceutical medication product's quality, safety, and effectiveness.