Guide on Post-approval Drug Substance Changes
FDA has posted a draft guidance entitled “Postapproval Changes to Drug Substances.” The document applies to synthetic drug substances and the synthetic steps involved in preparing semi-synthetic drug substances. It 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.