Displaying 2 results of Mesalazine Stable Isotopes Mesalazine, also known as 5-aminosalicylic acid (5-ASA), is a medication used to treat inflammatory bowel disease (IBD), such as ulcerative colitis and Crohn's disease. Mesalazine stable isotopes refer to isotopes of mesalazine that do not decay over time and maintain their chemical properties. These isotopes are commonly used in research and drug development to study the pharmacokinetics and metabolism of mesalazine in the body.