Roflumilast Impurity E is primarily used in the pharmaceutical industry for analytical and quality control purposes. It serves as a reference standard in the development and validation of analytical methods to ensure the purity and consistency of Roflumilast, a drug used to treat chronic obstructive pulmonary disease (COPD). By identifying and quantifying this impurity, manufacturers can monitor and control the production process, ensuring that the final drug product meets regulatory standards and is safe for patient use. Additionally, it aids in research studies to understand the degradation pathways and stability of Roflumilast, contributing to improved formulation and storage strategies.