Trilostane is a medication used in the treatment of Cushing's syndrome. It works by inhibiting the production of cortisol, a hormone that is overproduced in individuals with this condition. Trilostane impurities are substances that may be present in the medication in small amounts and can affect its purity, potency, and safety. These impurities can be the result of the manufacturing process, degradation, or contamination. Therefore, it is important to monitor and control the levels of trilostane impurities to ensure the quality and effectiveness of the medication.