Synonyms: 3-[1-Hydroxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]butyl]-alpha,alpha-dimethylbenzeneacetic acid, meta-Fexofenadine, Fexofenadine impurity B, 2-[3-[(1RS)-1-hydroxy-4-[4-(hydroxydiphenylmethyl)piperidin-1-yl]butyl]phenyl]-2-methylpropanoic acid