Sofosbuvir Impurity M is primarily used in the pharmaceutical industry for quality control and analytical purposes. It serves as a reference standard to ensure the purity and consistency of Sofosbuvir, a key drug used in the treatment of Hepatitis C. By identifying and quantifying this impurity, manufacturers can maintain compliance with regulatory standards and ensure the safety and efficacy of the final drug product. Additionally, it aids in the development and validation of analytical methods, helping researchers detect and monitor impurities during the drug synthesis process.