overview
Common Name: Tween 81
CAS Number: —
EINECS Number: —
Molecular Formula: —
Molecular Weight: —
Polysorbate 81 (Tween 81) is a member of the polysorbate family designed for emulsification and solubilization tasks in cosmetic and pharmaceutical formulations. It offers good dispersing ability for oil-soluble actives and can help form stable emulsions with pleasing sensory attributes. Polysorbate 81 is used where mildness and compatibility with biological ingredients are important.
Molecular structure description
Hydrophilic part: Polyoxyethylene (20) sorbitan head group
HLB value: ~11.0 (balanced emulsifier for mixed-phase systems)
Specifications
It is a nonionic surfactant composed of polyoxyethylene (5) sorbitan esterified with oleic acid, resulting in a moderately hydrophilic molecule with good emulsifying properties.
It is soluble in water and ethanol; partially soluble in isopropanol; and slightly soluble in vegetable oils.
When dispersed in water, it forms slightly hazy emulsions. Its intermediate HLB value makes it suitable for emulsions requiring higher oil compatibility.
| Test Parameter | Unit | Minimum | Maximum |
|---|---|---|---|
| Saponification Value | mgKOH/g | 45 | 55 |
| Hydroxyl Value | mgKOH/g | 65 | 80 |
| Acid Value | mgKOH/g | - | 2 |
| Moisture Content | % | - | 3 |
| Ash Content | w% | - | 0.25 |
| Oxyethylene Content | w% | 65 | 69.5 |
| Arsenic (As) | mg/kg | - | 3 |
| Lead (Pb) | mg/kg | - | 2 |
Applications
It is suitable for oil-in-water emulsions with unsaturated oils and offers a good balance of hydrophilic and lipophilic properties.
Its moderate hydrophilicity supports enhanced oil compatibility.
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 81 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
