Diethylamino hydroxybenzoyl hexyl benzoate is an organic compound also known as Ethylhexyl Triazone or Uvinul® T 150, is a chemical compound commonly used in sunscreens as a UV filter.

The name describes the structure of the molecule:

• Diethylamino indicates the presence of a functional group containing two ethyl groups (CH₃CH₂-) attached to a nitrogen (amino) atom.
• Hydroxybenzoyl suggests the presence of a benzoyl group (a benzene ring attached to a carbonyl group) that also has a hydroxyl (OH) group attached to the benzene ring.
• Hexyl indicates an alkyl chain with six carbon atoms.
• Benzoate refers to an ester of benzoic acid.

Description of the raw materials used in its production:

• Diethylamine is an organic compound that serves as a precursor in the synthesis of diethylamino hydroxybenzoyl hexyl benzoate. It is typically produced through the reaction of ethanol with ammonia.
• Hydroxybenzoic acid, also known as salicylic acid, is a carboxylic acid that is often derived from natural sources such as willow bark. It is an important starting material in the synthesis of diethylamino hydroxybenzoyl hexyl benzoate.
• Hexyl benzoate is an ester derived from hexyl alcohol and benzoic acid. It contributes to the overall structure and properties of diethylamino hydroxybenzoyl hexyl benzoate.

Industrial chemical synthesis step-by-step:

• Esterification - Diethylamino hydroxybenzoyl hexyl benzoate is synthesized through the esterification reaction of diethylamino hydroxybenzoyl chloride with hexyl benzoate. This reaction typically takes place under specific temperature and pH conditions, and a catalyst may be used to facilitate the reaction.
• Purification - The crude product obtained from the esterification reaction is purified to remove any impurities or by-products. This purification step may involve techniques such as filtration, distillation, or crystallization.
• Quality Control - The purified diethylamino hydroxybenzoyl hexyl benzoate undergoes rigorous quality control tests to ensure its purity, stability, and compliance with safety regulations and industry standards.
• Formulation - Diethylamino hydroxybenzoyl hexyl benzoate is incorporated into sunscreen formulations at specific concentrations to provide UV protection. It is often combined with other UV filters and active ingredients to achieve the desired sun protection factor (SPF) and broad-spectrum coverage.

It appears in the form of a white powder. 

What it is for and where

Cosmetics

Diethylamino hydroxybenzoyl hexyl benzoate provides protection against both UVA and UVB rays.

It is a restricted ingredient as VI/28 a Relevant Item in the Annexes of the European Cosmetics Regulation 1223/2009. Substance or ingredient reported: Benzoic acid, 2-[4-(diethylamino)-2-hydroxybenzoyl]-, hexylester

UV filter. It is the defining ingredient in sun creams that can mitigate the sun's ultraviolet (UV) radiation, which is a high risk factor for the development of skin cancer, erythema and photo-ageing. 

UV absorber. It acts by intercepting ultraviolet light before it can cause damage by reducing its energy through dissipation and returning it to a lower energy state.

Light stabilizer. It prevents light from degrading light-sensitive components and slows down degradation reactions that have already begun. The mechanism is, in a way, similar to antioxidants and the effectiveness depends on the.complexity of the formulation and the density of the product.

Diethylamino hydroxybenzoyl hexyl benzoate studies

• Molecular Formula: C₂₄H₃₁NO₄
• Molecular Weight: 397.515 g/mol
• UNII: ANQ870JD20
• CAS: 302776-68-7
• EC Number: 443-860-6  608-453-1
• PubChem Substance ID 329770267
• MDL number MFCD11616752

Synonyms:

• Hexyl 2-(4-(diethylamino)-2-hydroxybenzoyl)benzoate
• Uvinul A Plus
• DHHB
• Diethylamino hydroxybenzoyl hexyl benzoate
• Hexyl 2-[4-(Diethylamino)-2-hydroxybenzoyl]benzoate
• 2-[4-(DIETHYLAMINO)-2-HYDROXYBENZOYL]BENZOIC ACID HEXYL ESTER
• Benzoic acid, 2-[4-(diethylamino)-2-hydroxybenzoyl]-, hexyl ester
• 2-hydroxy-4-diethylamino-2'-hexyloxycarbonylbenzophenone
• n-Hexyl 2-(4-Diethylamino-2-hydroxybenzoyl)benzoate
• Benzoic acid, 2-(4-(diethylamino)-2-hydroxybenzoyl)-, hexyl ester

Diethylamino hydroxybenzoyl hexyl benzoate or, in abbreviated form, DHHB, has been shown to be poorly phototoxic and its most advantageous formulation (1) compared to other UV filters in this study.

However, some concerns remain regarding the environmental risk of water (2).

Other safety studies:

Cerqueira C, Nigro F, de Campos V, Rossi A, Santos-Oliveira R, Cardoso V, Beatriz Vermelho A, Dos Santos B, Mansur CRE. Nanovesicle-based formulations for photoprotection: a safety and efficacy approach. Nanotechnology. 2019 Apr 9. doi: 10.1088/1361-6528/ab177c

Abstract. Vesicular nanosystems are versatile and they are able to encapsulate actives with different solubilities, such as lipophilic and hydrophilic compounds. The most well-known vesicular nanosystems are liposomes and niosomes, the last one is formed by non-ionic surfactants. In the present work, we developed photoprotective niosomes containing sunscreens (octyl methoxycinnamate, diethylamino hydroxybenzoyl hexyl benzoate and phenylbenzimidazole sulfonic acid), non-ionic surfactants, cholesterol and stearylamine (positive-charged lipid). Studies based on dynamic light scattering techniques, entrapment efficiency and morphology by transmission electron microscopy were performed to characterize the niosomes. In addition, rheology, pH, in vitro sun protection factor (SPF) efficacy and toxicity and in vivo and in vitro safety were determined for the niosome formulations F-N1 and F-N2. The mean sizes of N1 and N2 were 168 ± 5 nm and 192 ± 8 nm, respectively, and their morphologies were spherical, unilamellar and with an entrapment efficiency of more than 45% for each sunscreen. Both formulations, F-N1 and F-N2 presented characteristics of pseudoplastic non-Newtonian fluids, showing declining viscosity with increasing shear rate applied. SPF values were considered satisfactory, 34 ± 8 for formulation F-N1 and 34 ± 5 for F-N2. The formulations did not present toxicity when tested in macrophages and the pH was compatible with skin, which minimizes allergies. The in vitro safety assay showed lipophilic sunscreens greater affinity for the epidermis, since this layer contains natural lipids. In vivo safety assay suggests that the increased skin retention of N2 is directly correlated with the positive charge of stearylamine. Stable photoprotective niosomes were obtained and were shown to be promising nanostructures to be used against solar radiation.

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Souza C, Maia Campos PMBG. Development of a HPLC method for determination of four UV filters in sunscreen and its application to skin penetration studies.
Biomed Chromatogr. 2017 Dec;31(12). doi: 10.1002/bmc.4029.

References______________________________________________________________________

(1) Kawakami CM, Máximo LN, Fontanezi BB, da Silva RS, Gaspar LR. Diethylamino hydroxybenzoyl hexyl benzoate (DHHB) as additive to the UV filter avobenzone in cosmetic sunscreen formulations - Evaluation of the photochemical behavior and photostabilizing effect. Eur J Pharm Sci. 2016 Dec 30;99:299-309. doi: 10.1016/j.ejps.2016.12.031

(2) Sánchez Rodríguez A, Rodrigo Sanz M, Betancort Rodríguez JR. Occurrence of eight UV filters in beaches of Gran Canaria (Canary Islands). An approach to environmental risk assessment.
Chemosphere. 2015 Jul;131:85-90. doi: 10.1016/j.chemosphere.2015.02.054.