Stability of 5-aminosalicylic acid suspension

The stability of 5-aminosalicylic acid in a suspension prepared extemporaneously for administration by enema was studied. The suspension was prepared (tragacanth was the suspending agent) and then placed in 3-ounce amber glass prescription bottles; five bottles were stored at room temperature and five were refrigerated for 90 days. Using samples from each bottle, concentrations of 5-aminosalicylic acid were determined in triplicate by high-performance liquid chromatography at 0, 30, 60, and 90 days. Throughout the study period, all samples retained more than 90% of the day 0 concentration of 5-aminosalicylic acid. At each storage time, concentrations in samples stored at either room temperature or under refrigeration were not significantly different. In this extemporaneously prepared suspension, 5-aminosalicylic acid was stable for 90 days at room temperature and under refrigeration.