Used primarily in research and development, it serves as a stable isotope-labeled internal standard in analytical studies, particularly in mass spectrometry. This allows for accurate quantification and pharmacokinetic analysis of mesalazine and its metabolites in biological samples. It aids in understanding drug metabolism, absorption, and excretion, supporting the development of more effective treatments for inflammatory bowel diseases like ulcerative colitis and Crohn's disease. Additionally, it is utilized in clinical trials to monitor drug efficacy and safety profiles.