Polysorbate 20 (Tween 20)

Polysorbate 20, commercially known as Tween 20, is a non-ionic surfactant widely used as an emulsifier, solubilizer, and stabilizer in various industries.
It is produced by the reaction of sorbitol with ethylene oxide and lauric acid, resulting in an amphiphilic compound capable of blending oil and water phases effectively.
Due to its excellent surface-active properties and mildness, Polysorbate 20 finds extensive applications in the cosmetic, pharmaceutical, food, and biotechnology sectors.

Chemical Structure

• Chemical Name: Polyoxyethylene (20) sorbitan monolaurate

• Molecular Formula: C₅₈H₁₁₄O₂₆

• Molecular Weight: ≈ 1228 g/mol

• Structure:

  • One sorbitol molecule (sugar alcohol backbone)

  • 20 ethylene oxide units (hydrophilic component)

  • One lauric acid ester group (lipophilic component)

• HLB Value: ≈ 16.7 (suitable for oil-in-water emulsions)

This unique structure provides both hydrophilic (water-loving) and lipophilic (oil-loving) properties, making it a highly effective surfactant and emulsifier.

Physical and Chemical Properties

Applications

1. Cosmetics and Personal Care

• Functions as an emulsifier in creams, lotions, shampoos, and cleansers

• Acts as a solubilizer for essential oils, fragrances, and active ingredients in aqueous systems

• Reduces surface tension to improve spreadability and uniform distribution

2. Pharmaceuticals

• Enhances the solubility of poorly soluble drugs

• Stabilizes emulsions and suspensions

• Used in vaccines, ophthalmic preparations, and injectables as a dispersing or wetting agent

3. Food Industry

• Serves as an emulsifier and stabilizer in sauces, ice creams, chocolates, and dairy products

• Improves texture, homogeneity, and prevents phase separation

4. Biotechnology and Microbiology

• Utilized for membrane protein extraction and virus inactivation

• Applied in cell culture and microbial preparation as a gentle detergent

Advantages

• Non-ionic nature: chemically stable across acidic and alkaline environments

• Excellent compatibility with a wide range of ingredients

• Produces stable, uniform emulsions

• Improves solubility of hydrophobic compounds

• Acts as an anti-static agent and viscosity modifier

• Vegan-friendly and non-comedogenic (does not clog pores)

Limitations

• Possible trace contamination with 1,4-dioxane during manufacturing (requires purification control)

• May cause mild skin irritation in sensitive individuals

• Can irritate eyes or skin at high concentrations

• Requires careful formulation control in pharmaceutical and cosmetic applications

Safety and Storage

• Safety: Considered safe for skin and hair when used within recommended limits and industrial standards.

• Recommended concentration: Typically 1–20% depending on the formulation.

• Handling precautions:

  • Avoid direct eye contact.

  • In case of irritation, discontinue use and seek medical advice.

• Storage conditions:

  • Store in tightly sealed containers.

  • Keep away from direct sunlight and excessive heat.

  • Maintain in a cool, dry environment (15–30°C).

Summary

Polysorbate 20 (Tween 20) is a versatile non-ionic surfactant known for its mildness, high water solubility, and emulsifying efficiency.
Its ability to combine oil and water phases makes it essential in cosmetics, pharmaceuticals, food formulations, and biotechnological applications.
With proper use and quality control, it provides stable, safe, and effective performance across a broad range of formulations.