Losartan potassium Impurity 2H dimer(USP) as potassium salt : 5-[4’-({2-Butyl-5-[(5-{4’-[(2-butyl-4-chloro-5-hydroxymethyl-1H-imidazol-1-yl)methyl]biphenyl-2-yl}-1 H-tetrazol-1-yl)methyl]-4-chloro- 2 H-imidazol-1-yl}methyl)biphenyl-2-yl]tetrazol, pot.