There has been some confusion about when an analytical method should be validated and when it should be verified. In fact,
there have been occasions when the terms have been used interchangeably. It is suggested that the term validation be reserved for the process necessary to demonstrate that a method is suitable for its intended purpose. Effective validation
begins with a proper statement of the purpose of the method. This statement should accompany the method validation report,
and in some circumstances, such as with Chapter ‹71› "Sterility Tests" (1), the statement should appear in the text accompanying
the method. Depending upon the degree to which robustness is assessed during the validation process, there may be a set of
conditions determined that may be suitable for the use of the method, and conditions that are contraindicated. If such conditions
have been established, it is helpful for them to accompany the text describing the method (for example, Method 3 in ).
The term verification should be reserved for the process whereby it is established that the conditions under which an article is to be tested by
a validated method are indeed suitable for that method. The verification process might be considered to include a subset of
the validation process, as suggested by Figure 1. The characteristics (data elements) of a validation process are contained
in several documents, and which of these are incorporated in the validation should be appropriate to the method's intended
purpose (and spelled out in the validation protocol.) The characteristics from the validation that are assessed during the
verification should be representative of the critical aspects of the method. An example of the verification of the range for
Method 3 was provided. Given that verification, as described in this article, is intended to address the suitability of a
particular set of conditions for use with a validated method, robustness is not likely to be important for the verification
For both validation and verification, one must remember the underlying purpose of the method. If the method is from the pharmacopeia
and is intended to be used in demonstrating that a pharmacopeial article meets requirements (for which there is a monograph),
the method is considered to be validated, and it would be necessary to verify that the test article is suitable for use with
the method. If the method is from the pharmacopeia but is not intended for use in satisfying monograph requirements, it may
need to be validated relative to the specific nonpharmacopeial purpose. If instead the method is not from the pharmacopeia
but is intended to satisfy monograph requirements, it must be validated as providing equivalent results to the pharmacopeial
method. Finally, if the nonpharmacopeial method is not intended to satisfy monograph requirements, it must be validated according
to its specific purpose, and this would not require comparison to any pharmacopeial method.
David A. Porter is a pharmaceutical consultant with Vectech Pharmaceutical Consultants, Inc. (Farmington, MI), email@example.com
Submitted: Oct. 26, 2006. Accepted: Dec. 11, 2006.
Keywords: qualification, USP, validation, verification
1. United States Pharmacopeia 29—National Formulary 24, United States Pharmacopeial Convention, (2006).
1. Pharmacopeial Forum
32 (2), 595–604 (Mar.–Apr. 2006).
3. Webster's Seventh New Collegiate Dictionary. (G. & C. Merriam Co., Springfield, MA, 1965).
4. International Conference on Harmonization Harmonized Tripartite Guideline, Validation of Analytical Procedures: Text and Methodology, (ICH, Geneva, Switzerland, 2005).
5. FDA, Center for Drug Evaluation and Research, Guidance for Industry: Analytical Procedures and Methods Validation Chemistry, Manufacturing, and Controls Documentation, (Rockville, MD, Aug. 2000).
6. FDA, Center for Drug Evaluation and Research, Guideline on General Principles of Process Validation, (Rockville, MD, May 1987).
7. FDA, Center for Biologics Evaluation and Research, Guidance for Industry Quality Systems Approach to Pharmaceutical Current Good Manufacturing Practice Regulations, (Rockville, MD, Sept. 2006).
8. FDA, Office of Regulatory Affairs, Guide to Inspections of Pharmaceutical Quality Control Laboratories, (Rockville, MD, July 1993).
9. Pappa et al., "Development of a New USP General Information Chapter: Verification of Compendial Procedures." Pharm. Technol.
30 (3), 164–169 (2006).