Various Agency and Industry groups have been talking about validation for more than 20 years.
The 1987 Drug Process Validation Guideline issued by CDER and ORA clearly defined the terms
prospective validation, retrospective validation, but not concurrent validation. When writing the
sections in this document, the EWG did not feel it was necessary to redefine these terms or to
include the definitions in this document.
The guidance does not define what these different approaches to validation are, but it does tell
you how to apply them to API processes. That was the intent.
