Symrise has added a broad-spectrum preservative to its cosmetic ingredients offering. SymOcide PS (INCI: Phenoxyethanol (and) Decylene Glycol (and) 1,2-Hexanediol) kills all microbes (>3 log reduction) including bacteria, yeast and mold in two to seven days in a variety of formulations.
The company recommends using the blend as an alternative to caprylyl glycol blends, especially if they cause stability or viscosity issues in emulsions. To improve preservative efficacy in difficult formulations such as sunscreens, the preservative can be combined with: 1-3% multifunctional ingredients such as the company’s Hydrolite 5 (INCI: Pentylene Glycol), the company’s SymDiol 68 (INCI: 1,2-Hexanediol (and) Caprylyl Glycol (and) Tropolone), hexylene glycol and 1,3-propanediol; 0.1-0.2% chelating agents such as EDTA and glutamate diacetate; or 0.1-0.2% preservative boosters such as anisic and levulinic acids.
The preservative blend: can be formulated into rinse-off formulations containing high concentrations on surfactants. The formulator should add the preservative blend post-emulsification and preferably to the water phase in emulsions. The blend is a clear, colorless liquid with low odor. It is recommended at up to 1.4% in formulations, and it is stable at both high and low temperatures. The blend is said to comply with regulations in United States, Europe and Japan.