Displaying 7 results of Phenytoin Impurities Phenytoin is an anticonvulsant drug used to treat epilepsy. However, during its manufacturing process, impurities may be introduced which can have negative effects on the drug's safety and effectiveness. These impurities may include related compounds, degradation products, and residual solvents. Careful monitoring and analysis of these impurities is necessary to ensure the quality and safety of phenytoin for patients.