[Code of Federal Regulations]
[Title 21, Volume 5]
[Revised as of April 1, 2001]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR320.29]

[Page 195]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                           SERVICES--Continued
 
PART 320--BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS--Table of Contents
 
      Subpart B--Procedures for Determining the Bioavailability or 
                     Bioequivalence of Drug Products
 
Sec. 320.29  Analytical methods for an in vivo bioavailability study.

    (a) The analytical method used in an in vivo bioavailability study 
to measure the concentration of the active drug ingredient or 
therapeutic moiety, or its 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 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 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 Sec. 320.31 are met.