Sofosbuvir impurity N is primarily used in the pharmaceutical industry for quality control and analytical purposes. It serves as a reference standard in the development and validation of analytical methods to ensure the purity and consistency of sofosbuvir, an antiviral medication. By identifying and quantifying this impurity, manufacturers can monitor and control the production process, ensuring the final drug product meets regulatory standards. Additionally, it aids in research studies to understand the stability and degradation pathways of sofosbuvir, contributing to the development of safer and more effective formulations.