Abstract
Following ICH guidelines, the stability of Belumosudil, a novel protein kinase inhibitor, was tested under different stress conditions (hydrolytic, oxidative, photolytic, and thermal). A selective and efficient separation of Belumosudil and its degradation products was achieved using a Quality by Design approach. In-silico predictions using Zeneth Nexus® software were employed to assess the compound's degradation under various stress scenarios. The methodology developed through experimental design analyzed crucial process parameters connected with chromatographic systems. Reversed-phase high-performance liquid chromatography with a C18 column and a gradient mobile phase of acetonitrile and 25 mM ammonium hydrogen carbonate buffer (pH 5.6) were utilized. For structural characterization and identification of degradation products, UPLC-quadrupole tandem mass spectrometry was employed. Four distinct degradation products were identified under different stress settings. The method was thoroughly validated, assessing accuracy, selectivity, repeatability, system suitability, and linearity range (5.0-120.0 μg/mL). To predict mutagenicity and toxicity, DEREK Nexus® software was used. Two degradation products were predicted to induce skin sensitization, irritation, and hepatotoxicity in humans.