Azilsartan Standard

1-[[2'-(2,5-Dihydro-5-oxo-1,2,4-oxadiazol-3-yl)[1,1'-biphenyl]-4-yl]methyl]-2-ethoxy-1H-benzimidazole-7-carboxylic Acid; 2-Ethoxy-1-[[2'-(4,5-dihydro-5-oxo-1,2,4-oxadiazol-3-yl)biphenyl-4-yl]methyl]benzimidazole-7-carboxylic Acid; 2-ethoxy-1-{[2-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)biphenyl-4-yl}methyl)-1H-benzo[d]imidazole-7-carboxylic acid; Azilsartan kamedoxomil Impurity B