part_subject: "BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS"
subpart_code: "B"
subpart_subject: "Procedures for Determining the Bioavailability or Bioequivalence of Drug Products"
section_number: "320.29"
section_subject: "Analytical methods for an in vivo bioavailability or bioequivalence study."
cfr_reference: "21 CFR 320.29"
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"
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(a)The analytical method used in an in vivo bioavailability or bioequivalence study to measure the concentration of the active drug ingredient or therapeutic moiety, or its active metabolite(s), in body fluids or excretory products, or the method used to measure an acute pharmacological effect shall be demonstrated to be accurate and of sufficient sensitivity to measure, with appropriate precision, the actual concentration of the active drug ingredient or therapeutic moiety, or its active metabolite(s), achieved in the body.
(b)When the analytical method is not sensitive enough to measure accurately the concentration of the active drug ingredient or therapeutic moiety, or its active metabolite(s), in body fluids or excretory products produced by a single dose of the test product, two or more single doses may be given together to produce higher concentration if the requirements of § 320.31 are met.