Metopimazine is a medication used for the treatment of nausea and vomiting. However, during the manufacturing process of Metopimazine, impurities may be introduced which can affect the quality and safety of the drug. These impurities may include related substances, degradation products, and residual solvents. It is important to monitor and control the levels of these impurities to ensure the purity and efficacy of the final product.