overview
Common Name: Tween 21 / Polyoxyethylene (20) sorbitan monomyristate
CAS Number: —
EINECS Number: —
Molecular Formula: —
Molecular Weight: —
Polysorbate 21 (Tween 21) is a nonionic surfactant derived from the ethoxylation of sorbitan monomyristate. It functions as an emulsifier and solubilizer in cosmetic, pharmaceutical, and food applications where mildness and clarity are desired. Polysorbate 21 helps form stable emulsions and improve wetting and dispersing of active ingredients, making it suitable for creams, lotions, and liquid formulations.
Molecular structure description
Hydrophilic part: Polyoxyethylene (4) sorbitan head group
HLB value: ~13.3 (moderately hydrophilic, suited for oil-in-water emulsions with medium polarity oils)
Specifications
It is a nonionic surfactant composed of polyoxyethylene (4) sorbitan esterified with lauric acid, resulting in a moderately hydrophilic molecule that can lower surface tension and stabilize emulsions.
It is soluble in water and ethanol; partially soluble in isopropanol; and slightly soluble in vegetable oils.
When dispersed in water, it produces clear to slightly hazy solutions. Its balanced hydrophilic-lipophilic profile makes it suitable for medium-polarity oil-in-water emulsions.
| Test Item | Unit | Min Value | Max Value |
|---|---|---|---|
| Saponification Value | mgKOH/g | 41 | 52 |
| Iodine Value | mgKOH/g | 90 | 107 |
| Acid Value | mgKOH/g | — | 2 |
| Moisture | % | — | 3 |
| Ignition Residue | w% | — | 0.25 |
| Ethylene Oxide | w% | 70 | 70.5 |
| Lead | mg/kg | — | 2 |
Applications
It is well-suited for oil-in-water emulsions and enhances the solubility of oils in aqueous systems.
Its moderate hydrophilicity makes it compatible with a wide range of formulation types.
Emulsification Efficiency – Stable W/O Emulsions
Sorbitan esters are highly effective in forming stable water-in-oil emulsions. Ideal for margarine, creams, and ointments, they help maintain consistency and prevent separation over time.
Mild & Skin-Friendly – Ideal for Cosmetics
Widely used in lotions, creams, and makeup products, sorbitan esters are non-irritating and suitable for sensitive skin. They provide smooth textures and enhance product stability.
Food Grade & Safe – Emulsifiers for Processing
Approved for food use, they act as emulsifiers in sauces, dairy products, and spreads. Improve mouthfeel, extend shelf life, and maintain homogeneity of processed foods.
Pharmaceutical Use – Enhances Drug Stability
Used in medicinal creams, gels, and suspensions, sorbitan esters help deliver oil-soluble actives effectively. They improve bioavailability and ensure long-term formulation stability.
storage & package
Storage:
Store in a cool, dry, and well-ventilated area, away from direct sunlight and sources of heat.
Avoid contact with harmful or incompatible substances. Handle with care during transportation to prevent leakage or contamination.
Transportation:
Transport as a general chemical product, following standard safety and handling procedures.
Package:
Polysorbate 21 is packed in high-quality PE drums with double-seal lids.
Standard packaging sizes include 25kg/drum, 200kg/drum, and 1000kg IBC tote to meet different usage needs.
25 Kg /drum
200kg/drum
