Nimodipine EP Impurity C Catalogue N231533 CAS 70172-96-2 M.W 434.44 M.F C21H26N2O8 Specifications FAQs O-Desisopropyl-O-methoxyethyl Nimodipine ; bis(2-Methoxyethyl) 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate