Both P25TiO2NPs (with or without vitamin B2) were not found beyond the epidermis in 99% of the analyzed TEM images (Fig. 8). This is coherent with previous findings showing that nanoparticles greater than 50 nm can not penetrate the skin, even in vivo models with movement, stretching, and friction [54]. However, in one of the zones, a few nanoparticles were observed inside a hair follicle. This could be due to the follicle exposure after the localized rupture of this physical barrier when rats were shaved in order to clean the area for cream topical administration. This finding suggests that nanoparticle-based sunscreen should not be applied on recently shaved or harmed skin, in order to avoid nanoparticle skin penetration.
Le produit obtenu par cette méthode est constitué de 29,4 % en masse de ZnS et 70,6 % en masse de BaSO4. Il existe des variations, par exemple l'adjonction de chlorure de zinc à la pâte avant chauffage produit un pigment plus riche en ZnS3.
So if you’re worried about titanium dioxide, don’t be! With current research and industry recommendations, titanium dioxide is a safe food additive. And if you want to avoid it, that’s ok too! Just don’t expect certain foods to be so white, smooth, and bright.
Le lithopone est produit par coprécipitation de sulfure de baryum et de sulfate de zinc, le plus souvent en proportions équimolaires, puis grillage de la pulpe résultante4.
