Question { Apotex, 11828 }

Is it necessary to validate both assay and related
substances for usp official methods for products.

Answer

Purity Tests: to ensure that all the analytical procedures performed allow an accurate statement of the content of impurities of an analyte, i.e.
related substances test, heavy metals, residual solvents content, etc.

Assay (content or potency):
to provide an exact result which allows an accurate statement on the
content or potency of the analyte in a sample.