The aim of this work was to examine particularly the Degussa P25 titanium dioxide nanoparticles (P25TiO2NPs) because they are among the most employed ones in cosmetics. In fact, all kinds of titanium dioxide nanoparticles (TiO2NPs) have gained widespread commercialization over recent decades. This white pigment (TiO2NPs) is used in a broad range of applications, including food, personal care products (toothpaste, lotions, sunscreens, face creams), drugs, plastics, ceramics, and paints. The original source is abundant in Earth as a chemically inert amphoteric oxide, which is thermally stable, corrosion-resistant, and water-insoluble. This oxide is found in three different forms: rutile (the most stable and substantial form), brookite (rhombohedral), and anatase (tetragonal as rutile), of these, both rutile and anatase are of significant commercial importance in a wide range of applications [3]. Additionally, the nano-sized oxide exhibits interesting physical properties, one of them is the ability to act as semiconducting material under UV exposure. In fact, TiO2NPs are the most well-known and useful photocatalytic material, because of their relatively low price and photo-stability [4]. Although, this photoactivity could also cause undesired molecular damage in biological tissues and needs to be urgently assessed, due to their worldwide use. However, not all nanosized titanium dioxide have the same behavior. In 2007, Rampaul A and Parkin I questioned: “whether the anatase/rutile crystal form of titanium dioxide with an organosilane or dimethicone coat, a common titania type identified in sunscreens, is appropriate to use in sunscreen lotions” [5]. They also suggested that with further study, other types of functionalized titanium dioxide could potentially be safer alternatives. Later, Damiani found that the anatase form of TiO2NPs was the more photoactive one, and stated that it should be avoided for sunscreen formulations, in agreement with Barker and Branch (2008) [6,7].
In a 2021, Chinese researchers examined the impact of E171 on lipid digestion and vitamin D3 bioaccessibility in a simulated human gastrointestinal tract model. They examined Vitamin D’s bioaccessibility, or the amount it was released in the gastrointestinal tract, becoming available for absorption, and found it “significantly decreased from 80% to 74%” with the addition of E171. In the experiment, E171 decreased lipid digestion dose-dependently. Researchers wrote: “The findings of this study enhance our understanding toward the potential impact of E171 on the nutritional attributes of foods for human digestion health.” The study was published in the Journal of Agricultural and Food Chemistry,
Panzhihua Dongfang Titanium Industry Co., Ltd. Dongfang, a well-known brand of titanium dioxide, a famous brand in Sichuan, a high-tech enterprise, a large supplier of titanium dioxide and titanium sponge, and one of the largest/leading titanium raw material production bases in China.