There are several types of tests that may be carried out under USP <61>. BA Sciences focuses on one of the only legally accepted methods under the USP pharmacopoeia. This method is aligned with international methods including European and Japanese pharmacopoeia methods.
During testing, a product sample is added to a culture medium. In this culture, any microbes present will thrive and, within 3 – 5 days, form “colony units” that are visible to the naked eye. By counting these units, the amount of bacteria and fungi present can be determined.
USP <61> also covers a number of preparation and validation (suitability testing) steps to ensure the accuracy of the test. Any microorganism inhibitors in the sample must be neutralized, since these types of compounds are often found in the raw materials that are used in pharmaceutical and cosmetic manufacturing. If present, these inhibitors may yield inaccurate results, since they prevent microbes from growing and being counted.
In addition, the culture method must be validated to ensure that it is capable of supporting the growth of the target microorganisms. If the culture method does not present the right environment for the target microorganisms to grow, testing will be similarly inaccurate and will not detect the presence of microbes, potentially presenting a danger to end users.
At BA Sciences, we offer expertise in each of these areas and more and are ready to assist you in any testing and validation needs that you may have.