CFR›Title 21›Chapter I›Part 320 ContainsSubparts A–BCorpusDaily eCFRDisplayed edition2026-05-13Last updated2026-05-13 PART 320—BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS Subparts A Subpart A—General Provisions Section 320.1 B Subpart B—Procedures for Determining the Bioavailability or Bioequivalence of Drug Products Sections 320.21–320.63 Authority21 U.S.C. 321, 351, 352, 355, 371. Previous 317 Part 317—Qualifying Pathogens Next 328 Part 328—Over-the-Counter Drug Products Intended for Oral Ingestion That Contain Alcohol