> Process-related impurities encompass those that are derived from the
manufacturing process, i.e., cell substrates (e.g., host cell proteins, host cell
DNA), cell culture (e.g., inducers, antibiotics, or media components), or
downstream processing (see appendix.B). Product-related impurities (e.g.,
precursors, certain degradation products) are molecular variants arising during
manufacture and/or storage that do not have properties comparable to those of the
desired product with respect to activity, efficacy, and safety