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# Drug Substance Q11 Guidance Out
- URL: https://www.fdaweb.com/drug-substance-q11-guidance-out/
- Published: 2018-02-23T12:00:00.000Z
- Updated: 2026-09-14T23:25:02.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5140835

FDA has published a guidance, *Q11 Development and Manufacture of Drub Substances (Chemical Entities and Biotechnological/Biological Entities) Questions and Answers*, to give additional clarification and to promote convergence and improve harmonization of the consideration for the selection and justification of starting materials and of the information that should be provided in marketing authorization applications and/or master files. The agency says the [document’s](https://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM542176.pdf?ref=fdaweb.com) focus is on chemical entity drug substances.

Requests for clarifications have come from those implementing the Q11 guidance on Development and Manufacture of Drug Substances worldwide, FDA says.