Phenylbutazone has the molecular formula C19H20N2O2 and its IUPAC name is 4-butyl-1,2-diphenylpyrazolidine -3, 5-dione. It has anti-inflammatory, antipyretic, and analgesic properties due to which it is widely used in the treatment of ankylosing spondylitis, rheumatoid arthritis, and reactive arthritis. It is available in the market as white or off-white crystalline powder. Initially, it feels like tasteless but after some time it taste bitter. The drug has no odor and its pH value is 8.2.