2-(hydroxymethyl)-4-[1-hydroxy-2-[6-(4-phenylbutan-2-yloxy)hexylamino]ethyl]phenol; 1-[4-HYDROXY-3-(HYDROXYMETHYL)PHENYL]-2-[[6-(1-METHYL-3-PHENYLPROPOXY)HEXYL]AMINO]ETHANOL; Salmeterol Related Compound B; Salmeterol xinafoate specified impurity E [EP]; UNII-R6O50AN25U; Salmeterol related compound B; Salmeterol related compound B RS [USP]; Salmeterol related compound B [USP]