Trimethylolpropane Tricaprylate/Tricaprate is a high-performance synthetic ester that provides a non-greasy, silky finish to skincare and cosmetic formulations. It functions primarily as a lightweight emollient and solvent, significantly improving the spreadability of sunscreens and color cosmetics while maintaining a “dry oil” feel.
- INCI Name:
- Trimethylolpropane Tricaprylate/Tricaprate
- Chemical/Scientific Name:
- 2-ethyl-2-(hydroxymethyl)propane-1,3-diol triester with octanoic and decanoic acids
- Common Aliases:
- TMP Tricaprylate/Tricaprate, Trimethylolpropane Caprylate/Caprate
| Category: | Softeners |
| Source Origin: | Synthetic |
| Comedogenic Rating: | 0-1 |
| Primary Industries: | Skincare, Suncare, Makeup, Haircare |
| Solubility: | Oil-soluble, Silicone-soluble |
At a Glance: Properties & Effects
| Hydration/Moisture | |
| Texture Enhancement | |
| Spreadability | |
| Irritation Risk |
- Primary Benefits: Provides a lightweight, velvety skin feel, prevents trans-epidermal water loss (TEWL), and serves as an excellent pigment dispersant.
- Potential Risks: Generally non-sensitizing and non-irritating for most skin types.
Biological Action & Cosmetic Profile
Structurally, this ingredient is a polyol ester derived from the esterification of trimethylolpropane with a blend of caprylic (C8) and capric (C10) fatty acids. Its branched molecular architecture prevents the heavy, occlusive weight associated with long-chain saturated fats. Upon application, the compound forms a breathable, semi-permeable film over the stratum corneum, trapping moisture within the epidermal layers without hindering gas exchange. This mechanism effectively reduces dryness and enhances the skin’s natural barrier resilience.
Formulation scientists value this ester for its low viscosity and high thermal stability. It exhibits a refractive index that imparts a natural-looking radiance to the skin surface, making it a preferred alternative to heavier lipids or certain grades of Dimethicone. Because it remains liquid at low temperatures and resists oxidation, it ensures the long-term structural integrity of emulsions, preventing the rancidity issues often found with natural botanical oils.
In the context of color cosmetics and sunscreens, the ingredient acts as a superior wetting agent for inorganic filters like titanium dioxide and zinc oxide. It ensures an even distribution of pigments, preventing the “chalky” or “patchy” appearance often seen in high-SPF products. Its compatibility with various oils allows it to bridge the gap between polar and non-polar phases in complex formulations.
Broader Applications & Origins
This synthetic lipid is frequently utilized in “oil-free” claims where traditional vegetable oils are avoided to minimize greasiness. Its chemical stability makes it an ideal candidate for hair care, where it provides lubricity and shine to the hair shaft without causing the buildup typically associated with heavy silicones. By reducing surface friction, it aids in detangling and heat protection during styling.
Routine Integration
- Synergies: This ester pairs effectively with other lipid-replenishing agents such as Squalane and Caprylic Capric Triglyceride to create multifaceted moisture barriers. It also enhances the delivery of oil-soluble antioxidants like Tocopherol. When combined with humectants like Glycerin, it creates a balanced hydration profile for both water and oil-depleted skin.
Clinical Consensus & Safety
Safety assessments by the Cosmetic Ingredient Review (CIR) Expert Panel have concluded that this ingredient is safe for use in cosmetic formulations under current practices. Dermatological testing, including rabbit ear comedogenicity assays, indicates that it does not promote follicular keratosis, unlike more aggressive esters such as Isopropyl Myristate. Furthermore, it is non-phototoxic and exhibits a very low potential for skin sensitization, making it suitable for sensitive skin populations and infant care products.
Is Trimethylolpropane Tricaprylate/Tricaprate safe for acne-prone skin?
Yes. Clinical studies indicate a very low comedogenic potential (rating of 0-1). It does not typically clog pores and is used in lightweight “dry-touch” lotions to provide moisture without exacerbating breakouts.
Is this ingredient natural or synthetic?
This is a synthetic ester. While the fatty acids used (caprylic and capric) can be sourced from coconut or palm oil, the final molecule is created through a specific chemical process to ensure a consistent, lightweight texture and superior stability compared to natural oils.
Why is it used in sunscreens?
It serves as an excellent solvent and dispersant for UV filters. It helps spread the sunscreen evenly across the skin, ensuring consistent protection and a more pleasant, non-sticky user experience.