⚠️ Auto-extracted by Claude on 2026-05-23 — not yet verified against full PDFs. Canonical identifiers (PubChem CID 59516799, CAS 55514-22-2, MW 540.6 Da, formula C36H24N6) cross-checked against PubChem. Mechanism + regulatory + efficacy claims sourced from PubMed abstracts of Pierre Fabre R&D publications + EU SCCS S86 opinion. Quantitative claims (HEV absorption %, BL-pigmentation reduction in Boyer 2023, biodegradation in Fagervold 2025) require full-PDF cross-check before relying.
TriAsorB (phenylene bis-diphenyltriazine, PBT)
INCI: phenylene bis-diphenyltriazine (sometimes PBDT in regulatory documents) IUPAC: 3-[4-(5,6-diphenyl-1,2,4-triazin-3-yl)phenyl]-5,6-diphenyl-1,2,4-triazine PubChem CID: 59516799 · CAS: 55514-22-2 · EC: 700-823-1 · MW: 540.6 g/mol · Formula: C₃₆H₂₄N₆
TriAsorB is a topical organic UV filter developed by Pierre Fabre Dermo-Cosmétique (parent of Avène), authorized by the EU SCCS in 2018 at ≤5% dermal concentration. It is a hybrid absorber + reflector of UVB through HEV (visible blue, 400–450 nm) — covering the broadest spectrum of any organic cosmetic UV filter in EU use as of 2026. It is the differentiating filter in the Avène Sunsimed and Intense Protect lines.
Structural note. TriAsorB is built on a 1,2,4-triazine scaffold (asymmetric, two N adjacent + one isolated), NOT the s-triazine (1,3,5) of Tinosorb S/M and bemotrizinol. The molecule is a bis-triazinyl-benzene without amine substituents — a structural class distinct from the Tinosorb family despite the shared “triazine” naming. This matters for cross-reactivity in contact-dermatitis settings: a patient sensitized to Tinosorb S does not necessarily react to TriAsorB and vice versa.
Mechanism — hybrid absorption + reflectance
TriAsorB is an oil-soluble particulate filter (suspended, not fully dissolved) with broad absorption across UVB, UVA, and visible blue, plus measurable reflectance in the HEV band that pure-absorber organic filters (Mexoryl 400, avobenzone, Tinosorb S) do not provide. Bacqueville et al. 2021 1 documented:
- Absorption: peaks in UVB + UVA-I + UVA-II + extending into 400–450 nm visible blue
- Reflectance: substantial in HEV; behaves partially like a tinted physical filter
- In reconstructed human epidermis (RHE), pre-applied TriAsorB-containing formula reduced 8-OHdG (oxidative DNA damage) from 412 nm blue light exposure and CPD/6-4PP from solar-simulated UV
- Critical wavelength ≥385 nm reported for finished formulas
The intrinsic dark red-brown color of TriAsorB gives finished products an inherent tint. TriAsorB-containing sunscreens can achieve HEV protection without requiring iron-oxide pigments, though iron oxides are often co-added for cosmetic uniformity (the TriAsorB tint alone is not aesthetically optimized for all skin tones).
This dual mechanism is the differentiator from MCE / Mexoryl 400, which is a pure absorber with λmax 385 nm focused on the UVA-I tail — TriAsorB extends further into visible light at the cost of less concentrated UVA-I-specific absorption.
Regulatory status
| Region | Status |
|---|---|
| EU | SCCS Opinion S86 / SCCS/1600/18 adopted 30 July 2018; concluded safe ≤5% in dermal sunscreen applications, unsafe in inhalable forms. Annex VI entry 32 added by Commission Regulation (EU) 2019/680 (30 April 2019). |
| Australia (AICIS / TGA) | Listed on AICIS inventory; usable in listed/listable sunscreens up to 5% (mirrors EU). |
| Canada (Health Canada) | NOT on Sunscreen Monograph. Products containing TriAsorB cannot be sold as Canadian sunscreens. |
| United States (FDA) | Not GRASE. No Time and Extent Application (TEA) filed. |
Human evidence
All published efficacy studies as of May 2026 are Pierre Fabre R&D-authored, mostly published in JEADV supplement issues. No independent replication. Endpoints focus on visible-light-induced pigmentation (blue-light challenge) rather than long-term photoaging hard outcomes.
| Study | Design | n | Key result |
|---|---|---|---|
| Bacqueville 2021 1 | In-vitro RHE + spectroscopy | RHE only | TriAsorB absorbs UVB+UVA+HEV, reflects HEV, weak IR; reduced 8-OHdG from blue light and CPD/6-4PP from solar-simulated UV |
| Bacqueville 2022 2 | Formulation paper / review | n/a | SPF50+ formula with TriAsorB + 3 co-filters; in-vitro photoprotection summary; supplement issue |
| Jacques 2022 3 | MALDI-MS imaging | Pig + human skin ex-vivo | TriAsorB remains in stratum corneum; minimal viable-epidermis penetration |
| Boyer 2023 4 | Two open intra-individual hemi-back RCTs | 20 + 16 women | 412 nm 50 J/cm² blue-light challenge; TriAsorB SPF50+ reduced BL-induced immediate pigmentation 50.7–75.5% colorimetric (p<0.001), 31.2–72.7% visual; effective in both tinted and non-tinted formulations |
| Le Digabel 2023 5 | In-vivo multispectral reflectance | Healthy volunteers (n undisclosed beyond “healthy”) | TriAsorB product showed significantly higher 380–450 nm absorbance than 5 SPF50+ commercial comparators (comparators not named) |
| Douki 2023 6 | Real-life summer exposure RCT (educated vs control) | n undisclosed | SPF50+ sunscreen reduced urinary + suction-blister pyrimidine dimers; formula contained TriAsorB but paper does not isolate the PBT contribution from the rest of the stack |
| Douki 2024 7 | RHE; sequential BL→UVB | RHE only | BL impaired CPD/6-4PP repair after subsequent UVB; pre-applied TriAsorB formula prevented the repair impairment |
Cross-line independent reference:
- Touti 2025 8 — L’Oréal-authored HDRS methodology paper (n=15) that compared 6 commercial sunscreens including TriAsorB-containing products. This is the only non-Pierre-Fabre publication characterizing TriAsorB efficacy; it argues that 4-wavelength interpolation methods misrank 380–400 nm protection — framing relevant to both TriAsorB and Mexoryl 400 efficacy claims. COI: L’Oréal (manufacturer of the competing MCE filter).
What’s missing from this evidence base:
- No independent (non-Pierre-Fabre) efficacy replication
- No published RCT comparing TriAsorB vs an iron-oxide-pigmented sunscreen on visible-light endpoints (so the marginal value of PBT’s chemical HEV absorption over iron-oxide pigment alone is not isolated)
- No head-to-head against Mexoryl 400
- No long-term outdoor photoaging RCT with histology
no-independent-replication · no-direct-comparator-rct
Safety
- EU SCCS S86 dossier reviewed acute, repeat-dose, dermal absorption, sensitization (HRIPT, LLNA), photo-sensitization, mutagenicity, reproductive tox — concluded safe ≤5% dermal. Inhalation excluded.
- No published case reports of contact sensitization or photoallergy as of May 2026 (PubMed indexed; absence is notable for a filter on the market since 2020).
- Dermal absorption minimal per Jacques 2022 MALDI-MS imaging — high MW (540 g/mol), particulate physical state, and stratum-corneum partitioning.
- Environmental persistence concern: Fagervold 2025 9 reported that TriAsorB was NOT biodegraded in marine sediment microcosms after 100 d (along with most modern triazine filters), whereas oxybenzone, homosalate, and octisalate were degraded. The aquatic-persistence finding cuts against the “reef-safer than legacy filters” framing — TriAsorB doesn’t bleach coral (no published evidence) but accumulates in sediments. Relevant for users prioritizing environmental impact alongside biological efficacy. long-term-unknown
Product availability
| Product line | Manufacturer | Region | TriAsorB in line? |
|---|---|---|---|
| Avène Sunsimed (medical-device line) — Sunsimed, Sunsimed KA, Sunsimed Pigment | Pierre Fabre | EU | Yes |
| Avène Solaire Intense Protect 50+ (TriAsorB debut, 2020) | Pierre Fabre | EU / UK / CA / AU | Yes |
| Avène B-Protect (older formula) | Pierre Fabre | EU | No — uses Mexoryl SX/XL |
| Avène Solaire UV Mineral SPF 50+ (US) | Pierre Fabre | US | No — ZnO formulation (FDA-GRASE compatible) |
| Anything else | — | — | No as of May 2026 — TriAsorB is Pierre Fabre proprietary |
US-market Avène sunscreens do not contain TriAsorB.
TriAsorB vs Mexoryl 400
The two newest broad-spectrum filters with 380+ nm coverage occupy adjacent but distinct niches:
| Property | TriAsorB (PBT) | Mexoryl 400 (MCE) |
|---|---|---|
| Manufacturer | Pierre Fabre / Avène | L’Oréal |
| MW | 540.6 g/mol | 322.4 g/mol |
| EU approval | 2019; ≤5% | 2020; ≤3% |
| Spectrum | UVB + UVA + HEV 400–450 nm | UVA-I 380–400 nm focused (λmax 385) |
| Mechanism | Hybrid absorber + reflector | Pure absorber |
| Visible-light protection without iron oxides | Yes (chemistry-based) | No |
| Avobenzone-free formulations available | Yes (Avène Sunsimed) | Co-formulated with avobenzone in UVMune 400 SKUs |
| Founder mechanistic paper | Bacqueville 2021 (DOI:10.1007/s43630-021-00114-x) | Marionnet 2022 (DOI:10.1016/j.xjidi.2021.100070) |
| Independent adverse-event reports | None | 1 (Loretan 2024 ACD case report) |
| Environmental persistence (marine sediment) | Resists biodegradation 9 | Not separately tested |
| Best fit | Melasma, post-inflammatory hyperpigmentation, fair skin with HEV pigment-trigger sensitivity, avobenzone avoidance | Maximum UVA-I gap-filling on top of an existing chemical stack |
Both have comparably thin independent evidence bases. Neither is FDA-approved. Both require import for US-based users.
Cross-references
- uv-protection — parent intervention page (filter sits in § Chemical filters → ultra-long UVA-I subsection)
- mexoryl-400 — competing 380+ nm filter (L’Oréal)
- krutmann-2017-skin-aging-exposome — exposome framework calling for visible-light protection alongside UV
- genomic-instability — UV-induced CPD/6-4PP/8-OHdG burden
- loss-of-proteostasis — MMP-driven dermal collagen/elastin degradation
- skin-aging — primary photoaging endpoint
Footnotes
Footnotes
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doi:10.1007/s43630-021-00114-x · Bacqueville D, Jacques C, Duprat L, et al. (Pierre Fabre R&D + CEA Grenoble) · Photochem Photobiol Sci 2021;20(11):1475–1486 · in-vitro (RHE) + spectroscopy · TriAsorB absorbs UVB+UVA+HEV, reflects HEV, weak IR; reduced 8-OHdG from blue light and CPD/6-4PP from solar-simulated UV in RHE · COI: all Pierre Fabre R&D + CEA Grenoble collaboration · founder mechanistic paper ↩ ↩2
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doi:10.1111/jdv.18196 · Bacqueville D, et al. · J Eur Acad Dermatol Venereol 2022;36 Suppl 6:29–37 · review/formulation paper · SPF50+ formula with TriAsorB + 3 co-filters; safety + in-vitro photoprotection summary · COI: Pierre Fabre R&D; supplement issue ↩
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doi:10.1016/j.jconrel.2022.04.040 · Jacques C, et al. · J Control Release 2022;347:78–88 · MALDI-MS imaging in pig + human skin · TriAsorB remains in stratum corneum, minimal viable-epidermis penetration · COI: Pierre Fabre ↩
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doi:10.1111/jdv.19290 · Boyer F, Cieslik C, Brugnara L, et al. · J Eur Acad Dermatol Venereol 2023;37 Suppl 6:12–21 · two open randomized intra-individual hemi-back studies · n=20 + n=16 women · 412 nm 50 J/cm² blue-light challenge; TriAsorB SPF50+ reduced BL-induced immediate pigmentation 50.7–75.5% colorimetric (p<0.001), 31.2–72.7% visual; tinted + non-tinted both effective · COI: Pierre Fabre; supplement issue; not blinded; small n · headline efficacy paper ↩
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doi:10.1111/jdv.19243 · Le Digabel J, Cieslik C, Borel M, et al. · J Eur Acad Dermatol Venereol 2023;37 Suppl 6:6–11 · in-vivo multispectral reflectance · TriAsorB product significantly higher 380–450 nm absorbance vs 5 SPF50+ comparators (unnamed) · COI: Pierre Fabre ↩
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doi:10.1016/j.xjidi.2023.100227 · Douki T, et al. · JID Innov 2023;3(6):100227 · real-life recreational summer exposure RCT (educated vs control) · SPF50+ sunscreen reduced urinary + suction-blister pyrimidine dimers; formula contained TriAsorB but PBT contribution not isolated · COI: Pierre Fabre + CEA ↩
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doi:10.1111/php.13921 · Douki T, et al. · Photochem Photobiol 2024;100(5):1359–1364 · RHE; BL → UVB sequence · BL impaired CPD/6-4PP repair after subsequent UVB; pre-applied TriAsorB formula prevented the repair impairment · COI: Pierre Fabre + CEA ↩
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doi:10.1111/phpp.70044 · Touti N, Renoux M, Nocairi H, Douezan S, Josso M (Passeron co-author) · Photodermatol Photoimmunol Photomed 2025;41(5):e70044 · n=15 in-vivo HDRS, 6 commercial sunscreens · methodology paper; broad-band interpolation misranks sunscreens at 380–400 nm · only non-Pierre-Fabre publication characterizing TriAsorB efficacy · COI: L’Oréal authors + Passeron (Anthelios consultant); frame accordingly — L’Oréal manufactures the competing Mexoryl 400 filter ↩
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doi:10.1007/s11356-025-36772-y · Fagervold SK, et al. · Environ Sci Pollut Res Int 2025;32(33):19823–19835 · marine sediment microcosms · TriAsorB not biodegraded after 100 d (along with most modern triazine filters); BP3/homosalate/octisalate were degraded · COI: Pierre Fabre co-funded · environmental-persistence finding cutting against “reef-safer than legacy” framing ↩ ↩2