Bioburden Method Suitability: A Practical Solution to Screening for Inhibition

ANSI/AAMI/ISO 11737-1:2018 addresses validation of the method for determination of bioburden. Clause 7 states that validation shall consist of four items, one of which is "assessment of test method suitability to demonstrate lack of inhibition of growth." Information must be provided, either through a rationale or via testing, showing that no inhibitory properties from the product exist in the specified bioburden test. However, the standard has no guidance on specific test methods for this particular purpose. Therefore, a simple bioburden suitability screening presented here could be used to quickly assess whether a product that is tested for bioburden has inhibitory substances that would be manifested in the bioburden test. The screening procedure uses a vegetative microorganism, Staphylococcus aureus, inoculated onto the product or into the extract solution, followed by the bioburden test procedure. A recovery of 70% or greater is recommended as acceptable for confirming the bioburden test Suitability.