- Research Article
- 10.1021/acsomega.5c13204
Identificationand Characterization of PerampanelDegradation Products: Stability-Indicating HPLC and In Silico ToxicologicalAssessment
- Mar 14, 2026
- ACS Omega
- Jéssica Domingos Da Silva + 8 more +8
A stability-indicatingHPLC-UV method enabling the simultaneousseparation and monitoring of perampanel (PER) and all degradationproducts was developed and applied, providing adequate resolutionand peak purity. Forced degradation studies were conducted to definethe degradation profile of PER under acidic, alkaline, oxidative,photolytic, and metal-ion stress conditions. Five degradation products(DP-1 to DP-5) were identified by HPLC–UV and structurallycharacterized by HRMS/MS, and 1D/2D NMR spectroscopy(1H, 13C, COSY, and HSQC). Acidic hydrolysisproduced a benzamide derivative (DP-1) and a benzoic acid derivative(DP-2), oxidative stress generated a pyridine N-oxidederivative (DP-3), and alkaline conditions yielded two previouslyunreported products, a ring-cleavage derivative of perampanel (DP-4)and a hydroxylated pyridone derivative of perampanel (DP-5). DP-1was also detected during accelerated stability studies of PER tabletsformulated with acidic excipients, demonstrating excipient–drugincompatibility under stressed storage conditions (40 °C/75%RH). The toxicity risk of the five degradation products was assessedusing complementary in silico approaches (statistical and expert-rulemethods) in accordance with ICH M7 guidance. None of the degradationproducts showed mutagenic concern and were therefore classified asICH M7 Class 4 or Class 5 impurities. These results expand the structuralknowledge of PER degradation products, clarify its main degradationpathways, and provide experimental and toxicological support for formulationdevelopment and impurity control.
Read more