Apremilast impurity is mainly used in pharmaceutical research analytical testing and quality-control studies related to apremilast drug products.

Its purpose is to serve as a reference or analytical standard for identifying monitoring and quantifying impurities or degradation products of apremilast during drug development and quality-control testing.

Apremilast impurity refers to a chemically related substance or degradation product associated with apremilast and its exact chemical structure depends on the specific impurity designation such as Apremilast Impurity A B or another specified impurity.