Polyglyceryl-3 Diisostearate

Polyglyceryl-3 Diisostearate – Non-Ionic Diester Emulsifier for Stable Emulsions and Enhanced Skin Feel

Basic Information

• INCI Name: Polyglyceryl-3 Diisostearate

• CAS Number: 9004-96-0 (general for polyglyceryl esters; specific grade may vary)

• Synonyms: Triglyceryl diisostearate, Polyglycerol-3 diisostearate, PG-3 Diisostearate

• Appearance: Pale yellow to amber viscous liquid or waxy solid

• HLB Value: Low to medium (suitable for W/O and O/W emulsions)

• Solubility: Soluble in oils and organic solvents; dispersible in water

• Storage: Store in tightly sealed containers in a cool, dry place, protected from light and moisture

Chemical Structure and Synthesis
Polyglyceryl-3 diisostearate is a non-ionic diester produced by the esterification of polyglycerin-3 (triglycerin) with two molecules of isostearic acid. The synthesis can be represented as follows:
PG₃ + 2 Isostearic Acid → Polyglyceryl-3 Diisostearate + 2 H₂O
where PG₃ denotes polyglycerin-3. The substitution of two hydroxyl groups with isostearyl chains enhances lipophilicity while retaining one free hydroxyl group, providing a balanced hydrophilic-lipophilic profile that enables effective emulsification and interfacial tension reduction.

Physicochemical Properties

• Enhanced lipophilicity: The two isostearyl chains improve solubility in oils and organic solvents, making it ideal for oil-rich formulations.

• Effective emulsifying activity: Reduces interfacial tension, stabilizing both water-in-oil (W/O) and oil-in-water (O/W) emulsions.

• Broad compatibility: Non-ionic nature ensures compatibility with a wide range of ingredients and pH levels.

• Thermal and chemical stability: Resistant to hydrolysis and oxidation under normal processing and storage conditions.

• Good skin compatibility: Mild and non-irritating, suitable for sensitive skin and baby care products.

• Biodegradable and derived from renewable plant-based sources.

Applications

• Cosmetics and personal care: Used as a primary or co-emulsifier, thickener, and stabilizer in W/O and O/W creams, lotions, serums, sunscreens, makeup removers, lip cosmetics, and hair care products. Provides stable, elegant textures with good spreadability, moisturizing properties, and emollient benefits.

• Pharmaceuticals: Employed as an emulsifier, solubilizer, and penetration enhancer in topical ointments, creams, and suppositories for uniform distribution of active ingredients.

• Lubricants: Applied to optimize rheological characteristics and provide stable coating structures.

• Industrial: Used as a dispersant, lubricant, and stabilizer in specialty chemical formulations.

Key Benefits

• Effective emulsification for both W/O and O/W systems.

• Mild and non-irritating – suitable for sensitive skin and baby products.

• Emollient properties – softens and conditions skin and hair.

• Excellent spreading and moisturization.

• Thermal and chemical stability – reliable performance over time.

• Biocompatible, biodegradable, and of natural origin.

• Compatible with a wide range of cosmetic, pharmaceutical, and industrial ingredients.

• Acts as a co-emulsifier, thickener, and stabilizer in complex formulations.

Recommended Use
Typical usage levels range from 1–5% of the formulation, depending on the desired emulsion stability, viscosity, and texture. For optimal performance, dissolve in the oil phase at elevated temperatures (60–70°C) before emulsification. Can be combined with co-emulsifiers and thickeners for tailored rheology.

Safety and Handling

• Generally recognized as safe for use in cosmetics and personal care at recommended concentrations.

• Low irritation potential; well-tolerated by skin and mucous membranes.

• Avoid contact with strong oxidizers and acids.

• Store in a cool, dry place, away from direct sunlight.

• Use appropriate personal protective equipment (gloves, safety goggles) when handling.

Quality Assurance
Each batch is tested for acid value, saponification value, and emulsification performance to ensure consistent quality.