Preparatory testing is similar to suitability testing and is used to determine the appropriate diluent/dilution factor, enrichment media required to neutralize any inherent antimicrobial properties of dietary supplements and nutraceuticals (tested according to USP chapters <2021> and <2022>) when sample preparations are challenged with specific, viable test microorganisms.
Antimicrobial Effectiveness
What is Antimicrobial Effectiveness Testing?
Antimicrobial effectiveness testing demonstrates the effectiveness of preservatives added to drug products when challenged with specific test microorganisms and monitored for 28 days. USP <51> is followed.
Antimicrobial preservatives are often added to pharmaceutical drugs that contain water as a solvent or medium in order to protect drugs from microbiological growth, or from microorganisms that may be introduced inadvertently during or after the manufacturing process. Alternatively, antimicrobial preservatives may be added to products that are packaged in multiple-dose containers that will be handled repeatedly by a consumer so that the growth of microorganisms are inhibited.
All useful antimicrobial agents are toxic substances. To protect consumers, the concentration of the preservative shown to be effective in the final packaged product should be below a level that may be toxic to human beings based on the recommended dosage of the medicinal product.
The concentration of an added antimicrobial preservative can be kept to a minimum if the active ingredients of a formulation are intrinsically antimicrobial. Antimicrobial effectiveness, whether inherent in the product or produced because of the addition of an antimicrobial preservative, must be demonstrated for all injections packaged in multiple-dose containers or for other products containing antimicrobial preservatives.
Antimicrobial effectiveness testing allows us to see how effectively the preservatives in a finished product kill off specified bacteria, called challenge organisms, during the time period that the product would be used by a consumer. Challenge organisms are generally based on likely contaminants to a drug product when considering the product’s physical attributes, formulation, and intended use.
What products typically require antimicrobial effectiveness testing?
Any product containing preservatives having antimicrobial properties would be subject to antimicrobial effectiveness testing.
What procedures do you follow for antimicrobial effectiveness testing?
We follow USP <51> for all antimicrobial effectiveness testing.
How should I send my product and /or sample?
The procedures and acceptance criteria for effectiveness apply to a product in the original, sealed container in which it has been or will be distributed by the manufacturer. The test does not need to be conducted in these containers, but please be careful to avoid using materials that can interact with the preservative in the containers that are used for antimicrobial effectiveness testing.
All samples must be sent in sterile containers.