Mesalazine EP Impurity - P

5-Amino-2-hydroxy-4'-sulfo-[1,1'-biphenyl]-3-carboxylic acid; 5-amino-2-hydroxy-3-(4-sulfophenyl)benzoic acid;5-Amino-3-(4-sulfonylphenyl)salicyclic Acid; 5-Amino-2-hydroxy-4'-sulfo-[1,1'-Biphenyl]-3-carboxylic Acid;