Cherney Blog: Inside The Petridish

Your blog resource for education, experience, and a good read!

Cherney Blog: Inside The Petridish

Your blog resource for education, experience, and a good read!

USP 61/62 Testing

Posted by Lauren Ellie on Jun 23, 2021 8:47:55 AM
Lauren Ellie
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USP Product Testing

 
The “USP” in USP testing is an abbreviation for United States Pharmacopeia. The United States Pharmacopeia is an independent, scientific nonprofit organization that develops standards used to test pharmaceutical raw materials, medicines, dietary supplements, and certain food ingredients. The wide variety of ingredients can include sweeteners, colorants, flavors, fats and oils, infant formula ingredients, processing aids, or preservatives.
 
 
Based on the product type and customer requirements, the product can be tested for either by one or both USP 61 and USP 62. These two chapters of testing are conducted to provide an estimate of the number of viable aerobic microorganisms and to demonstrate the absence of designated microbial species.
 
 
USP 61 - Microbiological Examination of Nonsterile Products: Microbial Enumeration Testing
 
The USP 61 test provides an enumeration of mesophilic bacteria/fungi that may grow under aerobic conditions.
 
 
 
Ok, but what do the terms mesophilic and aerobic mean?
 
Mesophilic organisms grow best in moderate temperature, neither too hot nor too cold
 
Aerobic refers to organisms that require oxygen-rich conditions.
 
There are two analytes that make up the USP 61 testing: Total Aerobic Microbial Content and Total Combined Yeast Mold Count. The Total Aerobic Microbial Content (TAMC) test will target mesophilic aerobic bacteria. The Total Combined Yeast Mold Count (TCYM) will target mesophilic aerobic fungi. Together these tests provide the total number of aerobic bacteria, yeast, and mold present within a sample. These tests are quantitative plate counts reported in CFU/g or CFU/mL.
 
  
 
 
USP 62 - Microbiological Examination of Nonsterile Products: Tests for Specified Microorganisms
 
The USP 62 tests are performed to determine the presence or absence of a specified list of microorganisms: Salmonella, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans, Clostridia species, and Bile-Tolerant Gram-Negative Bacteria.
 
 

All specified organisms or select organisms can be tested based on product and customer requirements. These tests are performed as individual qualitative enrichments that target each specific bacteria/group of bacteria. The USP 62 tests for specified microorganisms are reported as presumptive/positive or negative.

 

Suitability testing- Ensuring the correct sample preparation is used for your product! 
 
Another important facet to USP testing is the suitability test. Suitability testing should be done on products prior to submitting for testing. The purpose of suitability testing is to make sure the method and sample preparation is done to allow the lab to detect the presence of microorganisms.
 
 
Under what conditions would there be an issue with detecting organisms present? 
 
Some samples that fall under the scope of USP testing requirements can exhibit antimicrobial or inhibitory properties. The suitability testing would be performed to ensure that the sample preparation process is sufficient to be able to detect organisms if they were present. This process consists of testing to neutralize antimicrobials/inhibitory substances to ensure that organism recovery is possible. 
 
As stated above, suitability testing is typically done prior to submitting routine testing to ensure that the samples are tested to yield the most accurate results. Suitability work is done by product type and major changes made to the product should have suitability confirmed to ensure the testing methods do not need to be altered. 
 
 
Items to consider before submitting samples for USP microbial testing: 
 
  • Does your product require testing following USP methods?
  • What specific testing requirements do you need to meet?
    • Do you have acceptable limits/specs for your product?
    • Do you need USP 61, USP 62, or both?
    • Do you need to test for some or all of the specified microorganisms listed in USP 62?
  • Have you done suitability testing for your product?
    • If you have previous suitability testing done on the product, the lab will review the study prior to analyzing samples. If you have not had suitability testing done, just let the lab know and we can review your product!

 
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Interested in learning more about our USP testing capabilities, or more about us here at Cherney? Contact us via email or phone (920-406-8300) to learn more!

Topics: Education, FSMA, ISO 17025,, Cherney Micro, FSMA Compliance, Validated Methods, Product Testing, Pharmaceutical, USP Testing, USP 61/62