PT  - JOURNAL ARTICLE
AU  - Tidswell, Edward C.
AU  - Tirumalai, Radhakrishna S.
AU  - Gross, Deborah D.
TI  - Clarifications on the Intended Use of USP <61> Microbiological Examination of Nonsterile Products: Microbial Enumeration Tests
AID  - 10.5731/pdajpst.2023.012855
DP  - 2024 May 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - 348--357
VI  - 78
IP  - 3
4099  - http://journal.pda.org/content/78/3/348.short
4100  - http://journal.pda.org/content/78/3/348.full
SO  - PDA J Pharm Sci Technol2024 May 01; 78
AB  - In the execution of its legislated responsibilities, the United States Food and Drug Administration commonly refers to standard test methods detailed in the United States Pharmacopeia (USP). Microbiological test methods (contained in general chapters) are listed in chapters <51> to <80> with details regarded as enforceable where referenced as a test method. USP <61> “Microbiological Examination of Nonsterile Products: Microbial Enumeration Tests” is a globally harmonized chapter that has been successfully employed for the enumeration of microorganisms recoverable from nonsterile finished drug products. The content of USP <61> is not always scientifically principled nor emphatically understood by all pharmaceutical microbiologists. Consequently, misunderstanding and misapplication of USP <61> may result in analyses and assessments of microbiological quality that are flawed or erroneous. In this article, clarification is provided to assist the pharmaceutical microbiologist in the appropriate and intended use of USP <61>, including provision of details not always commonly known or understood.