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# Guide on Drug Substance Postapproval Changes
- URL: https://www.fdaweb.com/guide-on-drug-substance-postapproval-changes/
- Published: 2018-09-11T12:00:00.000Z
- Updated: 2026-09-15T00:31:05.000Z
- Author: David McFarland
- Tags: FDA Policy/General, #legacy-id-D5142322

*Federal Register* notice: FDA has made available a draft guidance entitled “Postapproval Changes to Drug Substances.” The document covers facility, scale, and equipment changes associated with all steps of drug substance manufacturing; specification changes to starting materials, raw materials, intermediates, and the unfinished and final drug substance; synthetic manufacturing process changes; changes in the source of drug substance; and change to container closure system of the drug substance. To view the notice, click [here](https://www.gpo.gov/fdsys/pkg/FR-2018-09-11/pdf/2018-19666.pdf?ref=fdaweb.com).