Preservatives inhibit or kill microorganisms, preventing spoilage and extending the shelf life of cosmetics. Ideally, preservatives should be effective against a wide range of microorganisms, soluble in water, non-toxic, non-irritating to the skin, stable and effective over a broad temperature range. Importantly, it should not cause discoloration, fading or unpleasant odor in the product.
Additionally, preservatives should have a neutral pH or at least not significantly affect the product’s pH, and should be economically viable and easily accessible. They should also not react with other organic compounds in the formulation.
In a review published in the Journal of Dermatologic Science and Cosmetic Technology, two Chinese researchers looked into the mechanism of action of preservatives in cosmetics.
Killing microbes
Co-author Zhenyu Tang, CTO at Henning Chemical (Shanghai) Co., Ltd, says, “The preservatives presented in this review, at normal use levels, kill the microorganisms rather than inhibiting their growth. These substances can affect various substructures of microbial cells, including the cell wall, cell membrane, enzymes involved in metabolism, protein synthesis systems, and genetic material.”
Notably, the effectiveness of a preservative depends on factors such as concentration, exposure time, and the specific microorganism being targeted.
Studying the mechanism of preservatives is important for several reasons.
“It helps in the development of improved preservation methods and the identification of more effective preservatives. Understanding how preservatives work allows for targeted modifications to enhance their antimicrobial properties,” adds Tang.
Further, studying the mechanism of action helps in determining the optimal conditions for the use of preservatives, such as concentration and exposure time, to ensure their effectiveness while minimizing any potential adverse effects.
“Overall, research on preservatives is crucial for monitoring their usage and establishing appropriate detection methods to prevent misuse and potential harm to human health,” says Tang.
No comments yet