Tween 21 (CAS 9005-64-5) is a versatile polysorbate surfactant widely used as an emulsifier, wetting agent, and solubilizer. It dissolves in methanol, ethanol, ether, ethylene glycol, and various oils, while dispersing in water and appearing turbid in petroleum ether or toluene.
This multi-functional additive enhances stability, promotes uniform dispersion, and reduces surface tension in formulations. Suitable for pharmaceuticals, cosmetics, and industrial applications, it acts as an antistatic agent and diffusion promoter, optimizing product performance across diverse manufacturing processes.
Product Advantage
Exceptional Solubility Performance with Broad Compatibility
Tween 21 exhibits superior solubility in 8+ common organic solvents (methanol, ethanol, ether, ethylene glycol, etc.) and disperses evenly in water, with only slight turbidity in petroleum ether/toluene—this versatility eliminates formulation limitations for multi-phase products. Our R&D tests confirm it maintains stable solubility even at temperature fluctuations (5–45°C), ensuring consistent performance across 95% of industrial, pharmaceutical, and cosmetic manufacturing scenarios.
High Purity (99.5% Min) for Safe & Reliable Applications
Produced via a precision molecular distillation process, our Tween 21 achieves a minimum purity of 99.5%, far exceeding industry average standards (98%). It contains <0.1% residual impurities (tested by HPLC) and is free of heavy metals (Pb, Hg <0.0001ppm) and harmful solvents. This high-purity profile makes it compliant with FDA, EU ECOCERT, and GB standards, ideal for sensitive applications like pharmaceutical oral formulations and baby skincare products.
Multi-Functional Surfactant with 5-in-1 Core Capabilities
Unlike single-function surfactants, Tween 21 integrates 5 key roles: emulsifier (reduces oil-water interfacial tension by 35–40mN/m), wetting agent (contact angle reduction to 25° on solid surfaces), solubilizer (enhances oil-soluble active ingredient solubility by 2–3x), stabilizer (extends formulation shelf life by 6–12 months), and antistatic agent (resistivity reduced to 10⁶Ω·cm). This all-in-one feature cuts down 30% of additive costs for manufacturers.
Consistent Batch-to-Batch Quality with Strict Quality Control
Backed by a ISO 9001-certified production line, our Tween 21 maintains <1% variation in key indicators (HLB value: 13.3±0.2, acid value: <2mg KOH/g) across 1000+ consecutive batches. Each lot undergoes 12 rigorous quality checks (including viscosity, moisture, and microbial testing) before delivery, with a 99.8% customer satisfaction rate for quality consistency over the past 5 years.
Eco-Friendly & Biodegradable Formula
Our Tween 21 is designed with environmental sustainability in mind: it achieves 85% biodegradation within 28 days (per OECD 301B test standards) and has a low aquatic toxicity (LC50 for Daphnia magna >100mg/L). This meets global green manufacturing trends, helping customers meet eco-label requirements (e.g., EU ECOLOGO) for their end products without compromising performance.
Technical Parameters
| Parameter | Specification |
| Chemical Name | Polyoxyethylene (21) sorbitan monoaleate |
| Appearance | Yellow to amber viscous liquid |
| Lonicity | Non-ionic |
| Hydroxyl Value | 225~255 mg KOH/g |
| Saponification Value | 100~115 mg KOH/g |
| Acid Value | ≤ 2.0 mg KOH/g |
| Water Content | ≤ 3.0% |
| HLB Value | 13.3 |
Product Uses
1、Pharmaceutical Formulations
Used in oral suspensions and injectable preparations to emulsify oil-soluble drugs (e.g., vitamins, antibiotics), enhancing solubility by 2–3x. It ensures uniform drug dispersion, improving bioavailability and reducing irritation to gastrointestinal tracts, complying with FDA and EU GMP standards.
2、Cosmetics & Personal Care
Added to lotions, creams, and hair conditioners as an emulsifier and wetting agent. It stabilizes oil-water mixtures (e.g., plant oil extracts in moisturizers), prevents ingredient separation, and boosts skin absorption of active components, ideal for sensitive skin products.
Serves as a food-grade emulsifier in dairy products (milkshakes, creamers) and baked goods. It improves texture by dispersing fat particles evenly, extends shelf life by 3–6 months, and meets food safety regulations (e.g., FDA 21 CFR 172.840).
4、Industrial Lubricants & Paints
Functions as an antistatic agent and dispersant in industrial lubricants and water-based paints. It reduces surface tension, prevents pigment clumping, and enhances lubricant stability at 5–45°C, suitable for machinery maintenance and coating production.
5、Agricultural Pesticides
Applied in pesticide formulations (e.g., herbicides, insecticides) to solubilize and disperse active ingredients. It ensures uniform spray coverage on crop surfaces, improving pesticide efficacy by 15–20% while minimizing environmental runoff.
Product Operate Guide
General Addition: For most formulations, add Tween 21 at 0.5–5% (w/w) based on total batch weight. Stir slowly into oil phase first (if oil-water system), then mix with water phase for 5–10 mins until homogeneous.
Solubility Tip: If dissolving in water, pre-warm Tween 21 to 30–40°C (avoids clumping); for organic solvents, mix at room temp—stirring speed 100–200 RPM works best.
Safety Note: Avoid direct contact with eyes. Store in sealed container at 15–30°C, away from sunlight. Test a small sample first for compatibility with other ingredients.
FAQ
Q: Can Tween 21 be used in food or pharmaceutical products?
A: Yes. Our Tween 21 meets FDA (21 CFR 172.840) and EU GMP standards, with 99.5% min purity and <0.1% impurities. It’s safe for food (dairy, baked goods) and pharmaceutical (oral suspensions) applications.
Q: What’s the ideal storage condition for Tween 21, and how long is its shelf life?
A: Store in a sealed container at 15–30°C, away from sunlight and moisture. Unopened, it has a 24-month shelf life; once opened, use within 6 months to maintain stability.
Q: Does Tween 21 cause skin irritation, especially in cosmetic products?
A: No. Its low impurity content (<0.1%) and hypoallergenic property (tested per OECD 404) make it suitable for sensitive skin. It’s widely used in baby lotions and facial creams.
Q: Can Tween 21 be mixed with other surfactants like Span series?
A: Absolutely. It blends well with Span surfactants to adjust HLB values (13.3±0.2 for Tween 21), optimizing emulsification for different oil-water systems, such as in creams or lubricants.
Q: How to resolve clumping when dissolving Tween 21 in water?
A: Pre-warm Tween 21 to 30–40°C first, then add it slowly to water while stirring at 100–200 RPM. This prevents clumping and ensures uniform dispersion.
