PEG-8 is a chemical compouns, a polyethylene glycol commonly used in cosmetic, pharmaceutical, and industrial products.

The name describes the structure of the molecule:

• PEG is an acronym for "Polyethylene Glycol," which is a polymer derived from ethylene oxide and water.
• 8 indicates the average number of ethylene oxide units in the polymer chain. In this case, "8" means there are eight repeating units of ethylene oxide.

Chemical Industrial Synthesis Process

• Preparation of reagents. The main raw materials include ethylene oxide (C₂H₄O) and an initial alcohol such as ethanol.
• Initiation of polymerization. Ethylene oxide is reacted with the initial alcohol in the presence of a catalyst, such as sulfuric acid, to initiate the polymerization reaction. This reaction forms an intermediate compound called an ethoxylate.
• Reaction control. The polymerization is conducted in a reactor at controlled temperatures and pressures to ensure a safe and efficient reaction. The ratio of ethylene oxide to the initial alcohol determines the polymer chain length and thus the molecular weight of PEG.
• Polymer chain growth. By continuing to add ethylene oxide, the polymer chain grows until it reaches the desired molecular weight, in this case, PEG-8.
• Termination of the reaction. The reaction is stopped once the desired molecular weight is achieved, and the product is neutralized to remove any traces of acidic catalyst.
• Purification. The crude PEG-8 is purified to remove impurities and reaction byproducts. This can be done using techniques such as vacuum distillation or filtration.
• Stabilization. The purified PEG-8 is stabilized to ensure its stability during transportation and storage, preventing oxidation and degradation.
• Quality control. The PEG-8 undergoes rigorous quality testing to ensure it meets standards for purity, efficacy, and safety. These tests include chemical analysis, spectroscopy, and microbiological testing.

What it is used for and where

PEG-8 is employed to enhance the solubility of oily or poorly soluble components in aqueous matrices. This humectant agent increases skin hydration by maintaining moisture on the epidermal surface, facilitating a more even application of cosmetic products. Its efficacy is demonstrated across a range of applications, including oral hygiene formulations, dermatological creams, lotions, and hair care preparations. Moreover, PEG-8 aids in forming a protective film on the skin that prevents transepidermal water loss, essential for maintaining skin water homeostasis.

Cosmetics - INCI Functions

• Humectant. Hygroscopic compound used to minimise water loss in the skin and to prevent it from drying out by facilitating faster and greater absorption of water into the stratum corneum of the epidermis.  The epidermis is the most superficial of the three layers that make up human skin (epidermis, dermis and hypodermis) and is the layer that maintains hydration in all three layers. In turn, the epidermis is composed of five layers: horny, the most superficial, granular, spinous, shiny, and basal. Humectants have the ability to retain the water they attract from the air in the stratum corneum and have the function of moisturising the skin. They are best used before emollients, which are oil-based.
• Solvent. It is the substance for dissolving or dispersing surfactants, oils, dyes, flavourings, bactericidal preservatives in solution.In fact, it dissolves other components present in a cosmetic formulation. Solvents are generally liquid (aqueous and non-aqueous).

Cosmetic Applications

Solubilizing Agent. PEG-8 is excellent for solubilizing water-insoluble ingredients, making it ideal for cosmetic formulations such as creams, lotions, and makeup products.

Emollient. Adds softness and smoothness to skin care products, enhancing the feel on the skin without leaving a greasy residue.

Formula Stabilizer. Helps stabilize emulsions, preventing the separation of components in creams and lotions.

Binder. Improves the texture and cohesion of cosmetic products, helping to keep the mixture of ingredients uniform.

Carrier. Facilitates the delivery of other active ingredients into the skin, enhancing the effectiveness of cosmetic products.

Other Applications

Pharmaceutical Industry. Used as an excipient in medications to improve the solubility and stability of active ingredients, as well as its ability to facilitate the absorption of drugs through the skin or mucous membranes.

Personal Care Products. Employed in shampoos, conditioners, and other hair care products to improve texture and manageability of hair.

Food Industry. Used as an additive in some foods to improve texture and stabilize emulsions.