Sustained effect of two antioxidants (oxothiazolidine and δ‐tocopheryl glucoside) for immediate and long‐term sun protection in a sunscreen emulsion based on their different penetrating properties

Abstract

Objective We investigated the dermal bioavailability and antioxidative properties of a sunscreen formulation containing two antioxidants, oxothiazolidine (OTZ) and δ‐tocopheryl glucoside (DTG). OTZ reacts directly with reactive oxygen species to form taurine, while DTG is metabolized in δ‐tocopherol to achieve antioxidative activities. Methods After topical application to a hair follicle‐derived reconstructed human epidermis (RHE) model, followed by solar‐simulated radiation, kinetics of bioavailability and antioxidative responses were measured over 24 h. Markers for oxidative stress were malondialdehyde (MDA), superoxide dismutase (SOD) and catalase activities. Results The two antioxidants had different bioavailability profiles: OTZ was rapidly and extensively absorbed, whereas DTG was slowly absorbed and converted to δ‐tocopherol. Compared to OTZ alone, the protection against effects on MDA levels and SOD and catalase activities was higher when DTG was used alone or in combination with OTZ. When used in combination, the degree of protection increased over time and remained constant over 24 h with maximal protection 2 h post‐irradiation. DTG slowly penetrated into the skin and was present in the skin at all post‐irradiation timepoints, thus allowing a slow but constant supply of δ‐tocopherol over at least 24 h. By contrast, the oxidative protection by OTZ was immediate but short‐lived due to its rapid penetration through the RHE and into the receptor fluid. Conclusion These results indicate a complementary sunlight protective action of OTZ and DTG with an immediate delivery of OTZ just after topical application of the formulation, and a prolonged skin delivery of δ‐tocopherol from the slower penetration and metabolism of DTG.

Formulation of a new broad‐spectrum UVB + UVA and blue light SPF50+ sunscreen containing Phenylene Bis‐Diphenyltriazine (TriAsorB), an innovative sun filter with unique optical properties

“…Moreover, using a combination of these filters allowed the quantities of each compound in the final product to be reduced, limiting their potential impact on the environment and ensuring that the product was in accordance with the manufacturers Eco friendly and Ocean Respect approach 61 . The pro‐vitamin E (tocopherol), which has antioxidant properties, has also been added to the SPF50 + sunscreen formulation to lessen the detrimental effects of sunlight‐induced photo‐oxidation on skin cells, and reinforce the preventive action of TriAsorB against oxidative stress 11,62 . Finally, the galenic formulation was developed avoiding the use of nanoparticles of inorganic filters, and with the aim of making the product pleasant to apply to encourage high levels of consumer compliance.…”

Improvement of performance for flexible film dosimeter by incorporating additive agents

“…Alternatively, this trend predominantly observed in reflection mode suggests that certain reactions may have influenced the reflectivity of the films. The excessive utilization of antioxidants can result in a pro-oxidant effect, leading to a potential decrease in antioxidative efficacy (Sakagami et al 2000, Sotler et al 2019, Jacques et al 2021. Therefore, when combining the two antioxidants PG and disodium EDTA, there is a possibility of diminished antioxidative effects.…”