polysorbate 40

overview

Product Name: polysorbate 40
Common Name: Tween 40 / Polyoxyethylene (20) sorbitan monopalmitate
CAS Number: 9005-66-7
EINECS Number: 215-664-8
Molecular Formula: C₆₂H₁₂₂O₂₆
Molecular Weight: 1284.60

Polysorbate 40 is a nonionic surfactant formed by the ethoxylation of sorbitol and sorbitan with approximately 20 moles of ethylene oxide per mole, followed by esterification with palmitic (palm) acid. The fatty acid source may be plant-based, animal-derived, or synthesized. It appears as a yellow liquid with a slight, characteristic odor. Polysorbate 40 is soluble in water and ethanol, but insoluble in mineral oil and vegetable oils. Its hydroxyl-to-palmitic acid ratio is approximately 3:1.

Molecular structure description

The molecule is based on sorbitol and its anhydrides, which are partially esterified with palmitic acid. Ethylene oxide units (~20 per molecule) are then added to create the hydrophilic segment.

The resulting structure features a hydrophilic polyoxyethylene chain and a lipophilic palmitate ester, giving it amphiphilic properties suitable for emulsification, wetting, solubilization, and dispersion.

Specifications

Polysorbate 40 combines a balanced hydrophilic–lipophilic structure, making it effective for emulsifying systems with moderate oil content. The following are typical quality control parameters.

Test Item	Unit	Min Value	Max Value
Saponification Value	mgKOH/g	100	115
Iodine Value	mgKOH/g	225	255
Acid Value	mgKOH/g	—	2
Moisture	%	—	3

Applications

Polysorbate 40 is used primarily as an emulsifier, wetting agent, solubilizer, lubricant, suspending agent, and viscosity enhancer in pharmaceutical formulations, including injection preparations—where the fatty acid source must be specified. In food applications, it is classified under emulsifiers (Category XVI) and may be used in various food types as needed, within appropriate usage levels.

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 40 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.