Polyglyceryl-2 Triisostearate

Polyglyceryl-2 Triisostearate – Fully Esterified Lipophilic Emulsifier for Stable Emulsions and Superior Texture

Basic Information

• INCI Name: Polyglyceryl-2 Triisostearate

• CAS Number: 86188-28-5 (general for polyglyceryl isostearates; specific grade may vary)

• Synonyms: Diglyceryl triisostearate, Polyglycerol-2 triisostearate, PG-2 Triisostearate

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

• HLB Value: Very low (highly lipophilic, suitable for W/O emulsions)

• Solubility: Soluble in oils and organic solvents; practically insoluble in water

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

Overview
Polyglyceryl-2 triisostearate is a non-ionic triester produced by the complete esterification of all hydroxyl groups of polyglycerin-2 (diglycerin) with three molecules of isostearic acid. This full substitution results in a highly lipophilic compound with no free hydroxyl groups, providing exceptional oil compatibility and water-repellent properties. Despite the absence of free –OH groups, its unique structure enables effective stabilization of water-in-oil (W/O) emulsions through uniform distribution of lipophilic fragments, reducing interfacial tension and improving texture. It is mild, biocompatible, and biodegradable, derived from renewable plant-based sources.

Chemical Structure and Synthesis
The complete esterification reaction can be represented as follows:
PG₂ + 3 Isostearic Acid → Polyglyceryl-2 Triisostearate + 3 H₂O
where PG₂ denotes polyglycerin-2 (diglycerin). Full substitution of all hydroxyl groups results in a highly lipophilic triester with enhanced oil affinity.

Physicochemical Properties

• Pronounced lipophilicity: Complete esterification ensures strong interaction with oil components and optimal oil compatibility.

• Emulsifying activity: Although lacking free –OH groups, the triester structure stabilizes emulsions through the uniform distribution of lipophilic fragments, promoting stable W/O systems.

• Texture-forming properties: Improves the consistency of cosmetic products, providing smoothness and stability to emulsion systems.

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

• Non-ionic: Compatible with a wide range of ingredients and pH levels.

Applications

• Cosmetics and personal care: Used as a primary or co-emulsifier in W/O creams, lotions, serums, sunscreens, makeup removers, lip cosmetics, and hair care products. Provides stable, elegant textures with excellent spreadability, moisturizing properties, and a non-greasy skin feel.

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

• High-lipid systems: Suitable for formulations requiring pronounced water-repellent effects and enhanced oil phase stability.

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

Key Benefits

• Effective W/O emulsification with excellent stability.

• Highly lipophilic – ideal for oil-rich and emollient formulations.

• Provides smooth, velvety textures with a pleasant skin feel.

• Water-repellent – suitable for waterproof and long-wear products.

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

• Biocompatible, biodegradable, and of natural origin.

• Compatible with a wide range of lipophilic 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 water resistance. 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.

• 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.