N-[2-hydroxy-5-[(1RS)-1-hydroxy-2-[[2-(4-methoxyphenyl)ethyl]amino]ethyl]-phenyl]formamide;Formoterol EP Impurity B;ForMoterol-IMpurity-B;Formoterol Impurity 2(Formoterol EP Impurity B);Formoterol impurity 2/Formoterol EP Impurity B/2-Hydroxy-5-[1-hydroxy-2-[[2-(4-methoxyphenyl)ethyl]amino]ethyl]formanilide;Formamide, N-[2-hydroxy-5-[1-hydroxy-2-[[2-(4-methoxyphenyl)ethyl]amino]ethyl]phenyl]-;Formetrol Impurity B;Formoterol Fumarate EP Impurity B