Micro-challenge test : Useful method for fast and high-throughput preservative efficacy testing
13 March 2016
Microbial contamination of cosmetic products is of great importance for the suppliers and the consumers. The
microbial growth is at the origin of organoleptic and formulation alterations (viscosity,color). To prevent microbial
contamination, addition of system preservatives are needed according to microbial sensibility of the cosmetic product and its use by consumers.
The research and validation of new preservatives system is not an easy project: Most of the scientific information relate to the antibiotics; identification of potential new preservatives products need large screening of samples; preservatives must be used at concentration as low as possible in order to avoid any toxic effects (except against the microbial strains); the new preservative system must be compatible with the formulation and the practices of use of the end product.
The regulatory method used to detect microbial contamination in cosmetics and their raw materials is based on traditional plate count, but even this challenge test method is very accurate, its time consuming and low throughput are the main drawback.