Opening a New Gate to Glass Preservative with Long-Lasting Antimicrobial Activity as Replacement of Parabens

In the past few years, the rapid and continuing emergence of antibiotic resistance for microbial pathogens has questioned the future utilization of antibiotics. Thus, the discovery of new antimicrobials is highly desired to fight microorganisms with multidrug-resistant capability. Here, we have used an inorganic UV filter as a model system to investigate the behavior of a new preservative, based on Ag-Zn cations, to replace parabens in sunscreens. The new glass preservative is incorporated into the UV filter composite by using an easy and ecofriendly method based on a dry nanodispersion. The Challenge Test clearly demonstrates a robust toxicity toward microorganisms, both the resistant bacteria and the fungi. This stimulant behavior can be explained by coupling between the antimicrobial activity of the Age and the antifungal activity of Zn2+. Importantly, leaching assays show that the controlled released of these cations over time results in a long-lasting antimicrobial property, pointing out that this material is a promising paraben-free candidate.