Temsirolimus is a medication used for the treatment of certain types of cancer. However, during the manufacturing process, impurities may be introduced, which can affect the effectiveness and safety of the drug. Temsirolimus impurities can include degradation products, residual solvents, and other impurities that can impact the purity and potency of the medication. Therefore, it is important to monitor and control the level of these impurities to ensure the quality of the final product.