Displaying 5 results of Methimazole Impurities Methimazole is a drug used to treat hyperthyroidism. However, during the manufacturing process, impurities may be introduced, which can affect the safety and efficacy of the drug. These impurities can include degradation products, residual solvents, and other contaminants. It is important to monitor and control the levels of these impurities to ensure the quality of the medication.