Molecular weight: 412.23

It’s true that titanium dioxide does not rank as high for UVA protection as zinc oxide, it ends up being a small difference (think about it like being 10 years old versus 10 years and 3 months old). This is not easily understood in terms of other factors affecting how sunscreen actives perform (such as the base formula), so many, including some dermatologists, assume that zinc oxide is superior to titanium dioxide for UVA protection. When carefully formulated, titanium dioxide provides excellent UVA protection. Its UVA protection peak is lower than that of zinc oxide, but both continue to provide protection throughout the UVA range for the same amount of time.

The production of ROS was studied on white blood cells as a model to screen the effect on eukaryotic cells after being exposed to samples and solar simulated irradiation (according to the level of penetration under the skin). For that purpose, the leukocytes were separated from anticoagulated fresh blood using the Ficoll-Hypaque reactive in a well-known technique [33]. Then, 50 μL of suspensions of P25TiO₂NPs (0.2 mg/mL and 0.02 mg/mL), vitaminB2@P25TiO₂NPs (0.2 mg/mL and 0.02 mg/mL) and vitamin B2 (0.2 mg/mL and 0.02 mg/mL) were prepared and mixed with 50 μL of white blood cells suspension. A solution of 3% H₂O₂ was used as positive control and PBS as negative control. Then, the samples were irradiated using the LED panel for 3 and 6 h to simulate the light penetration into the skin. Also, a set of samples was kept in the dark as control. Finally, the ROS were detected through the colorimetric assay employing the nitroblue tetrazolium salt (NBT salt) and the absorbance at 650 nm was measured. The experiment was reproduced twice; the standard deviation was calculated and p-value < 0.05 were considered significant.