Sorbitan Sesquiisostearate
What is Sorbitan Sesquiisostearate?
Sorbitan Sesquiisostearate is a non-ionic surfactant formed by reacting sorbitol—a sugar alcohol sourced from starches like corn—with sesqui (1.5 equivalents) of isostearic acid, a branched fatty acid from vegetable oils such as rapeseed or olive. This creates a lipophilic ester effective in cosmetic formulations. It appears in water-in-oil emulsions, anhydrous products like lipsticks, foundations, and eyeshadows, as well as oil-in-water creams. By reducing interfacial tension between immiscible phases, it forms a protective film at the oil-water boundary, preventing droplet coalescence and ensuring long-term product stability and smooth application. Its mild hydrophobic properties suit barrier creams and pigmented cosmetics.
Roles in Formulation
This ingredient serves the following purposes in cosmetic formulations:
Benefits
Enables stable mixing of oils and water for even-textured products
Provides gentle surface tension reduction to support cleansing
Helps maintain formulation integrity during storage and use
Who It's For
A quick guide for who this ingredient may suit (and who should be cautious).
| Who May Benefit | Who Should Avoid |
|---|---|
| Users of cream or lotion moisturizers needing consistent blends | Those with rare allergies to sorbitan derivatives |
| People with skin preferring non-comedogenic emulsifiers | People sensitive to fatty acid esters |
| Individuals using makeup foundations for smooth wear | Individuals preferring fully anhydrous products |
Safety Notes
- Considered safe in typical cosmetic concentrations by regulatory reviews
- Displays low comedogenic potential in formulations
Frequently Asked Questions about Sorbitan Sesquiisostearate
What is Sorbitan Sesquiisostearate made from?
It comes from esterifying sorbitol from starches with isostearic acid from vegetable oils.
Is it suitable for sensitive skin?
It shows low irritation potential as a non-ionic surfactant in cosmetics.
In which products is it used?
Common in foundations, lipsticks, creams, and lotions for emulsion stability.