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# 2 Guides on Clin Pharm and Bioavailability
- URL: https://www.fdaweb.com/2-guides-on-clin-pharm-and-bioavailability/
- Published: 2019-02-25T12:00:00.000Z
- Updated: 2026-09-15T01:07:30.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5143458

FDA has published two draft guidances to help drug developers get agency approval. The first [draft guidance](http://app.info.fda.gov/e/er?utm%5Fcampaign=SBIA%20-%20FDA%20Issues%202%20Draft%20Guidances%20for%20Industry%2C%20%E2%80%9CAssessing%20the%20Effects%20of&utm%5Fmedium=email&utm%5Fsource=Eloqua&s=2027422842&lid=6632&elqTrackId=B3B3FCAF3C897F63D57D01E0C64D5D7B&elq=9f93b2f632f54c988b556ad63461854d&elqaid=6864&elqat=1), “Assessing the Effects of Food on Drugs in INDs and NDAs — Clinical Pharmacology Considerations,” provides recommendations to sponsors planning to conduct food-effect studies for orally administered drug products as part of INDs, NDAs and supplemental NDAs. It revises and replaces part of a 2002 FDA guidance entitled, “Food-Effect Bioavailability and Fed Bioequivalence Studies.”

The other [draft guidance](http://app.info.fda.gov/e/er?utm%5Fcampaign=SBIA%20-%20FDA%20Issues%202%20Draft%20Guidances%20for%20Industry%2C%20%E2%80%9CAssessing%20the%20Effects%20of&utm%5Fmedium=email&utm%5Fsource=Eloqua&s=2027422842&lid=6631&elqTrackId=2ADD511DB9DA4F11C193FE16834369A3&elq=9f93b2f632f54c988b556ad63461854d&elqaid=6864&elqat=1), “Bioavailability Studies Submitted in NDAs or INDs — General Considerations.” The document contains advice on how to meet bioavailability (BA) requirements set forth in 21 CFR part 320 as they apply to oral dosage forms. It is also applicable to non-orally administered drug products when it is appropriate to rely on systemic exposure measures to determine the BA of a drug (e.g., transdermal delivery systems and certain rectal and nasal drug products). The guidance also provides advice on conducting relative BA studies during the IND period for a drug intended to be submitted for approval in an NDA and bioequivalence studies during the post-approval period for certain drug product changes.