Tiabendazole is an antifungal drug used to treat various fungal infections. Impurities are byproducts or unwanted substances that can be present in the drug during manufacturing or storage. Tiabendazole impurities can affect the purity and efficacy of the drug, and may also cause adverse effects on the patient. Therefore, it is important to monitor and control the levels of impurities in tiabendazole to ensure its safety and effectiveness.