Polyglyceryl-2 Oleate is a chemical compound, an emulsifying agent commonly used in various cosmetic and personal care products.

Chemical Composition and Structure

Polyglyceryl-2 Oleate is an ester formed from the reaction of oleic acid, a fatty acid derived from natural oils, and polyglycerol, which is derived from glycerol through a polymerization process. The chemical structure includes a polyglycerol backbone with two glycerol units (Polyglyceryl-2) esterified with oleic acid. This combination provides both hydrophilic (water-attracting) and lipophilic (oil-attracting) properties, making it an effective emulsifier.

Physical Properties

Polyglyceryl-2 Oleate typically appears as a yellow to amber viscous liquid or semi-solid. It is soluble in oils and dispersible in water, forming stable emulsions. The ingredient is known for its mildness, making it suitable for use in products designed for sensitive skin.

Chemical Industrial Synthesis Process

• Preparation of reagents. The main raw materials include glycerol and oleic acid.
• Esterification. The glycerol is heated and treated with oleic acid in the presence of a catalyst, such as sulfuric acid (H₂SO₄) or p-toluenesulfonic acid. This process forms polyglycerides (polymers of glycerol).
• Polyglycerolization reaction. The glycerol is polymerized to polyglycerol-2 (a molecule of glycerol with two glycerol units) through a polymerization reaction.
• Formation of Polyglyceryl-2 Oleate. The polyglycerol-2 reacts with oleic acid through an esterification reaction to form Polyglyceryl-2 Oleate.
• Neutralization. The reaction mixture is neutralized with a base, such as sodium hydroxide (NaOH), to remove excess acidic catalyst.
• Cooling. The reaction mixture is cooled to room temperature.
• Washing. The mixture is washed with deionized water to remove any soluble impurities.
• Drying. The washed product is dried at controlled temperatures to remove residual moisture and obtain a dry product.
• Filtration. The solution is filtered to remove any solid impurities.
• Grinding. The dried product is ground to obtain a fine and uniform powder.
• Classification. The dried powder is classified to ensure a uniform particle size. This step may involve sieving or the use of air classifiers.
• Stabilization. The Polyglyceryl-2 Oleate is stabilized to ensure its stability during transportation and storage, preventing aggregation and degradation.
• Quality control. The Polyglyceryl-2 Oleate undergoes rigorous quality testing to ensure it meets standards for purity, safety, and functionality. These tests include chemical analysis and spectroscopy.

What it is used for and where

Cosmetics

Polyglyceryl-2 Oleate is an emulsifier derived from vegetable fatty acids, commonly used in cosmetic products for its ability to form stable and delicate emulsions. It is particularly valued for its emollient properties and skin compatibility.

Cosmetics - INCI Functions

• Surfactant - Emulsifying agent. Emulsions are thermodynamically unstable and are used to soothe or soften the skin and emulsify, so they need a specific, stabilising ingredient. This ingredient forms a film, lowers the surface tension and makes two immiscible liquids miscible. A very important factor affecting the stability of the emulsion is the amount of the emulsifying agent. Emulsifiers have the property of reducing the oil/water or water/oil interfacial tension, improving the stability of the emulsion and also directly influencing the stability, sensory properties and surface tension of sunscreens by modulating the filmometric performance.

Cosmetic Applications

Natural Emulsifier. It helps mix water-based ingredients with oily components, creating uniform and stable cosmetic products such as creams, lotions, and cleansers.

Emollient Properties. Provides a feeling of softness and hydration on the skin, enhancing the texture of skincare products.

Skin Compatibility. Thanks to its plant origin, it is well tolerated by the skin and suitable for use on all skin types, including sensitive skin.

Versatility in Formulation. Can be used in a variety of cosmetic products, including eco-friendly and natural ones, due to its effectiveness and natural origin.

Enhancing the Penetration of Active Ingredients. Facilitates the absorption of active ingredients into the skin, enhancing the effectiveness of skincare products.

Other Applications

Hair Care Products. Used in conditioners and hair treatments to improve cleansing and hair condition, leaving hair soft and easy to comb.

Pharmaceutical Products. Employed in pharmaceutical formulations for its ability to stabilize emulsions and improve the texture of products.

Safety

Polyglyceryl-2 Oleate is generally considered safe for use in cosmetic and personal care products when used according to recommended guidelines (1). It is biodegradable and poses minimal risk to the environment. As with all ingredients, it is important to follow proper usage levels to avoid any potential skin irritation.

References__________________________________________________________________________

(1) Fiume MM, Bergfeld WF, Belsito DV, et al. Safety Assessment of Polyglyceryl Fatty Acid Esters as Used in Cosmetics. International Journal of Toxicology. 2023;42(2_suppl):5S-101S. doi:10.1177/10915818231174440

Abstract. The Expert Panel for Cosmetic Ingredient Safety (Panel) assessed the safety of 274 polyglyceryl fatty acid esters. Each of the esters in this group is a polyether comprising 2 to 20 glyceryl residues, end-capped by esterification with simple carboxylic acids, such as fatty acids. Most of these ingredients are reported to function in cosmetics as skin-conditioning agents and/or surfactants. The Panel reviewed the available data and considered conclusions from their relevant previous reports, and determined that these ingredients are safe in cosmetics in the present practices of use and concentration described in this safety assessment when formulated to be non-irritating.

Teeranachaideekul, V., Soontaranon, S., Sukhasem, S., Chantasart, D., & Wongrakpanich, A. (2023). Influence of the emulsifier on nanostructure and clinical application of liquid crystalline emulsions. Scientific Reports, 13(1), 4185.

Abstract. Liquid crystals are appealing in pharmaceutical and cosmetic fields due to their unique structures that combine the properties of both liquid and solid states. Forming an emulsion into liquid crystals can be affected by a number of factors, including the emulsion composition and temperature. Changing the types and concentrations of surfactants could be another factor that affects liquid crystals. Currently, most liquid crystal research focuses on the nanostructure of liquid crystal systems without evaluating the efficacy of liquid crystals clinically. In this study, liquid crystalline emulsions made from camellia seed oil with four different surfactants (Olivem 1000, Polyaquol-2W, Nikkomulese LC, and Lecinol S-10 with Tween 80) were created. The liquid crystal emulsions were formulated in the form of oil-in-water (o/w) emulsions with Camellia oleifera seed oil serving as the main ingredient in the oil phase (10% w/w). All formulations exhibited liquid crystal characteristics with lamellar structures as determined by the polarized light microscopy and small-angle X-ray scattering with supporting data of the nanostructure from wide-angle X-ray scattering and differential scanning calorimetry (DSC). They all showed good stability under normal (room temperature) and accelerated conditions (4 °C and 40 °C) in long-term storage (6 months). Using the reconstructed human epidermis as a skin model, all formulations did not cause skin irritation. In the clinical trial, all formulations were able to reduce transepidermal water loss (TEWL) and increase skin hydration immediately after application. This lasted at least 10 h. All formulations showed distinct Maltese crosses under the polarized light microscope with a positive result for liquid crystals in wide angle X-ray scattering (WAXS) and small angle X-ray scattering (SAXS) methods. Moreover, among all formulations tested, Formulation D, which contained Lecinol S-10 and Tween 80 as emulsifiers, showed the most robust interaction between the surfactant and water molecules in the lamellar structure under DSC. The formulation was stable in long-term normal and accelerated conditions. Above all, Formulation D, which was formulated with Lecinol S-10 with Tween 80, had the best clinical result, was nonirritating to the skin, and can be used as a cream base in the pharmaceutical and cosmeceutical sectors.