B. Koroskenyi, J. Salmen, M. T. Fontan Yanes
Symshield®, also known as barrier technology or hurdle technology, is a concept of combining several physical or chemical factors aiming at inhibiting microbial growth. This systematic approach has been proven successful as it strengthens the microbiological product protection systems of cosmetic formulations, thus ensuring long-term product quality and safety. Relying on this technology, multifunctional ingredients are often used in combination with preservatives or other antimicrobial enhancers and are commonly applied as part of the product protection system. While typically chemical ingredients are used as barriers in these combinations such as organic acids, chelating agents, surfactants, etc., it is important not to overlook the possible beneficial effects of physical parameters. Ultimately, this extensive approach has the potential to create a more robust product protection system or even lower the necessary use level of traditional antimicrobial compounds in the formula. In this series of publications, we present studies to demonstrate how the antimicrobial product protection effectiveness of multifunctional cosmetic ingredients, which are known product protection enhancers, can be optimized by combining them with additional barriers, such as pH, water activity, organic acids, chelating agents, etc. In the first part of the series, we examine the effect of pH and organic acids.