eCFR Reference Browser

---

title: "21 CFR §320.28"

source: "https://www.ecfr.gov/current/title-21/section-320.28"

title_number: "21"

volume_number: "5"

chapter_number: "Unknown"

subchapter_code: "D"

subchapter_subject: "DRUGS FOR HUMAN USE"

part_code: "320"

part_subject: "BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS"

subpart_code: "B"

subpart_subject: "Procedures for Determining the Bioavailability or Bioequivalence of Drug Products"

section_number: "320.28"

section_subject: "Correlation of bioavailability with an acute pharmacological effect or clinical evidence."

cfr_reference: "21 CFR 320.28"

title_name: "Title 21"

title_subject: "Food and Drugs"

parts_covered: "Parts 300 to 499"

revised_date: "Revised as of April 1, 2019"

publication_date: "As of April 1, 2019"

contains_description: "Containing a codification of documents of general applicability and future effect"

publication_info: "Published by the Office of the Federal Register National Archives and Records Administration as a Special Edition of the Federal Register"

---

Correlation of in vivo bioavailability data with an acute pharmacological effect or clinical evidence of safety and effectiveness may be required if needed to establish the clinical significance of a special claim, e.g., in the case of an extended release preparation.

§320.28 - Correlation of bioavailability with an acute pharmacological effect or clinical evidence.