Idelalisib is a pharmaceutical drug used in the treatment of certain types of cancer. During the manufacturing process, impurities can sometimes be introduced into the drug. These impurities can negatively affect the drug's potency and safety. Therefore, it is important to identify and control these impurities to ensure the drug's quality and effectiveness. Various analytical techniques are used to detect and quantify these impurities, and strict regulations are in place to ensure their control.