Benzeneacetic acid, 4-[1-hydroxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]butyl]-ฮฑ,ฮฑ-di(methyl-d3) hydrochloride,2-(4-(1-hydroxy-4-(4-(hydroxydiphenylmethyl)piperidin-1-yl)butyl)phenyl)-2-(methyl- d3)propanoic-3,3,3-d3 acid hydrochloride,Fexofenadine Stable Isotopes