Compositions comprising 5-amino-2-hydroxybenzoic acid (5-amino salicylic acid, mesalamine) and a reducing sugar, e.g., lactose, undergo the Maillard and other chemical reactions and produce, in the case of lactose, a degradant 5-[2-Formyl-5-(hydroxymethyl)-1H-pyrrol-1-yl]-2-hydroxybenzoic acid. Inventors have developed means to contain and/or reduce the formation of degradants of 5-amino-2-hydroxybenzoic acid.