Displaying 2 results of Phenylbutazone Impurities Phenylbutazone is a nonsteroidal anti-inflammatory drug used to treat pain and inflammation. However, it may contain impurities that can potentially harm the user. These impurities can include various isomers, analogs, and related compounds that are not intended to be present in the drug. It is crucial to monitor and control these impurities to ensure the safety and efficacy of the drug.