FDA announced the availability of a final guidance for industry entitled ‘‘Q7 Good Manufacturing Practice Guidance for Active Pharmaceutical Ingredients: Questions and Answers.’’  This guidance was prepared under the auspices of the International Council for Harmonisation (ICH), formerly the International Conference on Harmonisation, and is  intended to clarify uncertainties due to the interpretation of certain sections of ICH Q7 and to help ensure that all active pharmaceutical ingredients (APIs) meet the standards for quality and purity they purport or are represented to possess.

Go to Q7 using this link:  https://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM605076.pdf