Ecamsule
[CAS# 92761-26-7]

Identification

• Classification: Analytical chemistry >> Standard >> Analytical standard
• Name: Ecamsule
• Synonyms: [(3E)-3-[[4-[(E)-[7,7-dimethyl-3-oxo-4-(sulfomethyl)-2-bicyclo[2.2.1]heptanylidene]methyl]phenyl]methylidene]-7,7-dimethyl-2-oxo-1-bicyclo[2.2.1]heptanyl]methanesulfonic acid
• Molecular Formula: C₂₈H₃₄O₈S₂
• Molecular Weight: 562.69
• CAS Registry Number: 92761-26-7
• EC Number: 410-960-6
• SMILES: CC1(C2(C(=O)/C(=C/C3=CC=C(C=C3)/C=C4/C(=O)C5(C(C4CC5)(C)C)CS(=O)(=O)O)/C1CC2)CS(=O)(=O)O)C

Properties

• Density: 1.4±0.1 g/cm³ Calc.^*
• Index of refraction: 1.637 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS05 Danger
• Risk Statements: H318
• Safety Statements: P264+P265-P280-P305+P354+P338-P317

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Serious eye damage	Eye Dam.	1	H318

• Transport Information: UN 3261

Discovery and Applications

Ecamsule, also known by its chemical name terephthalylidene dicamphor sulfonic acid, is an organic compound used as a sunscreen agent to protect the skin from the harmful effects of ultraviolet A (UVA) radiation. It was developed and patented by L’Oréal in the late 1980s and introduced into commercial sunscreen formulations in the early 1990s. It is marketed under trade names such as Mexoryl SX.

Ecamsule functions as a UVA filter, absorbing wavelengths in the range of 320 to 400 nanometers, with peak absorption around 345 nanometers. UVA radiation penetrates deeper into the skin than UVB and is primarily responsible for premature aging, immunosuppression, and contributing to skin cancer development. The ability of ecamsule to absorb UVA rays makes it an effective component in broad-spectrum sun protection products.

One of the key properties of ecamsule is its photostability. Unlike many older sunscreen agents that degrade upon exposure to sunlight, ecamsule maintains its structural integrity and UV-absorbing capacity even after prolonged UV exposure. This characteristic helps ensure consistent protection over time and reduces the risk of the formation of harmful photodegradation byproducts.

Ecamsule is a water-soluble compound, which makes it particularly suitable for incorporation into aqueous-based formulations such as lotions, creams, and gels. It is often combined with other UV filters to broaden the overall spectrum of protection, including agents that cover the UVB range. In addition to enhancing efficacy, these combinations can also stabilize each other in formulations.

The use of ecamsule has been approved in several regions, including the European Union, Canada, Australia, and parts of Asia. In the United States, its use is limited to formulations approved through a New Drug Application process, and it is not currently included in the FDA’s monograph for over-the-counter sunscreen ingredients. However, it is available in select products that have gone through specific regulatory approval processes.

Safety assessments of ecamsule have demonstrated that it is well tolerated when applied topically. It has low skin penetration, minimal systemic absorption, and does not exhibit phototoxic, mutagenic, or endocrine-disrupting effects. Clinical studies and post-marketing surveillance have supported its use as a safe and effective UVA filter.

In practical applications, ecamsule is used in cosmetic and dermatological products intended for daily sun protection or for extended outdoor exposure. It plays an essential role in reducing the risk of photoaging and UVA-induced skin damage, especially when used as part of a broad-spectrum sunscreen formula.

In summary, ecamsule is a photostable, water-soluble UVA filter widely used in sunscreen formulations to protect against long-wave ultraviolet radiation. Developed in the late 20th century, it contributes to broad-spectrum sun protection and has an established record of safety and efficacy in topical use.

References

2008. Sunscreens containing the broad‐spectrum UVA absorber, Mexoryl® SX, prevent the cutaneous detrimental effects of UV exposure: a review of clinical study results. Photodermatology, Photoimmunology & Photomedicine, 24(4).
DOI: 10.1111/j.1600-0781.2008.00365.x

2007. Mexoryl: A Review of an Ultraviolet A Filter. Plastic and Reconstructive Surgery, 120(4).
DOI: 10.1097/01.prs.0000280561.02915.3a

2002. Determination of water-soluble UV-filters in sunscreen sprays by liquid chromatography. Journal of chromatography. A, 979(1-2).
DOI: 10.1016/s0021-9673(02)01411-5