Postapproval Changes to Drug Substances; Draft Guidance for Industry; Availability

The Food and Drug Administration (FDA or Agency) is announcing the availability of a draft guidance for industry entitled ``Postapproval Changes to Drug Substances.'' This draft guidance provides recommendations to holders of approved new drug applications, abbreviated new drug applications, new animal drug applications, abbreviated new animal drug applications, and holders of drug master files and veterinary master files who may want to make a change to the drug substance manufacturing process during the drug product application postapproval period. The draft guidance applies to synthetic drug substances and the synthetic steps involved in the preparation of semisynthetic drug substances. The draft guidance covers facility, scale, and equipment changes associated with all steps of drug substance manufacturing; specification changes to starting materials, raw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.