5-Aminosalicylic acid, Mesalamine, 95%

Mesalazine (INN, BAN), also known as mesalamine (USAN) or 5-aminosalicylic acid (5-ASA), is an anti-inflammatory drug used to treat inflammatory bowel disease, such as ulcerative colitis and mild-to-moderate Crohn's disease. Mesalazine is a bowel-specific aminosalicylate drug that acts locally in the gut and has its predominant actions there, thereby having few systemic side effects.

As a derivative of salicylic acid, mesalazine is also thought to be an antioxidant that traps free radicals, which are potentially damaging byproducts of metabolism. Mesalazine is the active moiety of sulfasalazine, which is metabolized to sulfapyridine and mesalazine.

Mesalazine is the active component of the prodrug balsalazide along with the inert carrier molecule 4-aminobenzoyl-beta-alanine.