Ethylhexyl triazone (Octyl triazone)

Ultrafast Transient Absorption Spectroscopy of the Sunscreen Constituent Ethylhexyl Triazone

The ultrafast photoprotection mechanisms in operation in ethylhexyl triazone (EHT, octyl triazone), an approved ultraviolet-B (UV-B) chemical filter for commercial sunscreens, remain elusive, with a notable absence of ultrafast time-resolved measurements. These large organic molecules are of increasing interest as they are suspected to be less likely to penetrate the skin than some of the smaller approved filters, thereby reducing the possible adverse effects from sunscreen products. We apply femtosecond transient absorption spectroscopy with electronic structure calculations to unravel the complete photodeactivation mechanism that EHT undergoes after UV-B irradiation. We propose that this involves ultrafast internal conversion of the initially photoexcited n1ππ* state that couples to the ground state via a 11ππ*/S0 conical intersection, enabling multiple absorption and recovery cycles, as one would anticipate from a highly efficient filter. We also observe long-lived photoproducts which, based on previous studies along with present electronic structure calculations, we attribute to trapped excited populations in the S1 and T1 states.

Quantification of sunscreen ethylhexyl triazone in topical skin-care products by normal-phase TLC/densitometry

Ethylhexyl triazone (ET) was separated from other sunscreens such as avobenzone, octocrylene, octyl methoxycinnamate, and diethylamino hydroxybenzoyl hexyl benzoate and from parabens by normal-phase HPTLC on silica gel 60 as stationary phase. Two mobile phases were particularly effective: (A) cyclohexane-diethyl ether 1 : 1 (v/v) and (B) cyclohexane-diethyl ether-acetone 15 : 1 : 2 (v/v/v) since apart from ET analysis they facilitated separation and quantification of other sunscreens present in the formulations. Densitometric scanning was performed at 300 nm. Calibration curves for ET were nonlinear (second-degree polynomials), with R > 0.998. For both mobile phases limits of detection (LOD) were 0.03 and limits of quantification (LOQ) 0.1 μg spot(-1). Both methods were validated.

Dosage de l'octyl triazone dans les produits cosmétiques solaires

Summary Dosage of octyl triazone in cosmetic sunscreen products. The method describes the quantitative determination of octyl triazone [2, 4, 6-trianilino-p-(carbo-2'-ethylhexyl-1'-oxy)-1, 3, 5-triazine] in cosmetic sunscreen products. The sample is suspended in tetrahydrofuran and after appropriate treatment the determination is made by HPLC.

In vivo Human Skin Penetration of the UV Filter Ethylhexyl Triazone: Effect of Lipid Microparticle Encapsulation

Background/aims: The data available on the skin permeability of ethylhexyl triazone (EHT), a widely used high-molecular-weight (823.1-Da) UV filter, are scarce and obtained only via in vitro studies. Therefore, we evaluated in vivo the penetration of EHT in human stratum corneum by the tape stripping technique. Moreover, the effect of EHT encapsulation in lipid microparticles (LMs) on its diffusion through the stratum corneum was examined.
Methods: LMs loaded with EHT were prepared using glyceryl behenate and phosphatidylcholine. Creams containing EHT free or encapsulated in LMs in conjunction with the two most commonly used UV filters, octyl methoxycinnamate (OMC) and butyl methoxydibenzoylmethane (BMDBM), were applied to human volunteers and the fraction of the applied sunscreen dose having penetrated into different stratum corneum layers was measured.
Results and conclusion: For the cream with the nonencapsulated sunscreen agent, the percentage of the applied EHT dose diffused into the stratum corneum was 21.9 ± 4.9%, not significantly different from that of the smaller-molecular-weight OMC (22.2 ± 7.6%) and BMDBM (20.5 ± 3.7%). A marked (45.7%) and statistically significant reduction in the in vivo skin penetration of EHT was attained with the cream containing microencapsulated EHT. The decreased percutaneous penetration provided by the LMs should favor the efficacy of EHT and limit potential toxicological risks.

Assessing the eco-compatibility of new generation sunscreen products through a combined microscopic-molecular approach

There is now unequivocal evidence that sunscreen can severely affect marine ecosystems. However, so far, most studies have focused on the impact of single sunscreen ingredients rather than on the whole sunscreen products, which are released into the marine environment. In the present work, we investigated the ecological impact of six formulations, which represent the "new generation" organic UV filters such as diethylamino hydroxybenzoyl hexyl benzoate (DHHB), methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT), ethylhexyl triazone (EHT), and bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT), which are progressively replacing the "old generation" organic UV filters (e.g., oxybenzone, octinoxate) banned in several countries of the world. The six formulations tested were characterized by a different combination of ingredients, on a model species particularly sensitive to environmental alterations: the sea urchin, Paracentrotus lividus. We investigated the sea urchin responses both in terms of gene expression and anomalies in embryonic development. We found that all sunscreen products containing only MBBT, DHHB, BEMT, and EHT as UV filters, are more eco-compatible than those also containing also ES, or other ingredients such as emollients and texturizing compounds, which may act synergistically causing molecular stress, morphological anomalies, and ultimately possible death. Overall, the results presented here provide new insights on the effects of sunscreen products based on "new generation" UV filters, and highlights the urgency of testing complete formulations, rather than just specific UV filters to ascertain the eco-compatibility of sunscreen products, to effectively minimize their impact on marine ecosystems.