Mesalazine Impurity E ; 4-Amino-2-hydroxybenzoic acid ; 4-aminosalicylic acid (EP);3-Hydroxy-4-carboxyaniline;4-Carboxy-3-hydroxyaniline;Apacil; Apas; Deapasil; Entepas; Gabbropas; Monopass;Para-aminosalicylic Acid; Paramycin; Parasal; Parasalicil; Parasalindon; Pasa; Pasalon; Pasara; Pasem; Paser; Pasmed; Pasnodia; Pasolac; Propasa; Rezipas; Sanipirol-4;