Cholestan is a steroid compound that is commonly used in the pharmaceutical industry. However, during the manufacturing process, impurities can be introduced, which can impact the safety and efficacy of the final product. These impurities can include residual solvents, degradation products, and other byproducts that can be harmful to human health. Therefore, it is important to monitor and control cholestan impurities to ensure that pharmaceutical products are of the highest quality and purity.