PEGs are polyethylene glycol derivatives resulting from a polycondensation reaction and, depending on the structure of the derivative molecule, have specific applications in cosmetic products. As a relatively short-chain molecule,PEG-9 is primarily used as a humectant, emulsifier and stabiliser. It is successfully used in many pharmaceutical formulations (soft capsules, bowel movement aids) and hygiene products (toothpastes, ointments).
The group of synthetic ethylene oxide polymers is generally referred to as PEGs. It is a blanket term for ethylene glycol derivatives. They are formed by the so-called condensation polymerisation reaction. A characteristic feature of polyethylene glycols is that the structure of their polymer chain is varied. Depending on the number of ethylene glycol units in the molecule, “different” PEGs are distinguished. PEG-9 is therefore an ethylene glycol derivative containing nine ethylene glycol units in its structure. The CAS number of the compound is 25322-68-3. PEG-9 is a colourless viscous liquid.
As an ingredient mainly in pharmaceutical preparations,PEG-9 acts primarily as an emulsifier and solubiliser. As a surfactant, it helps to combine two phases that do not mix – the oil phase and the water phase. It is a texturising ingredient. It is responsible for creating and maintaining the proper texture of the product, preventing, for example, its separation into layers, and helping in its proper application. It has softening and moisturising properties. In addition, it has an anti-electrostatic effect. PEG-9 also acts as a humectant. As a product component, the surfactant is responsible as a humectant for binding water molecules which are part of the cosmetic formulation. This allows the remaining ingredients to be effectively and evenly distributed.
PEG-9, sold by the PCC Group under the name POLIkol 400PF, meets strict quality requirements specified in the most recent edition of the European Pharmacopoeia. The high quality of the product allows it to be classified as a macrogol. Macrogols are raw materials with molecular weights between 300 and 3350 daltons. They are characterised by strong water-binding properties, they are not absorbed from the gastrointestinal tract but remain there and exert an osmotic effect. These properties of macrogols are commonly used in medications facilitating bowel movement. PEG-9 can be mixed with higher molar mass macrogols (e.g. greater than 3000 g/mol). It then takes the form of a paste, which is used as a base for making ointments. Other pharmaceutical uses of PEG-9 include eye and ear drops. In eye drops, it effectively helps alleviate dryness and irritation caused by wind, air conditioning, sun, and even certain medications. PEG-9 in eye drops helps keep the eye moist, protects it from injury and infection, and reduces symptoms such as itching and burning.
PEG-9 is considered a safe ingredient for consumers, as are all ingredients in the broad group of polyethylene glycols. Since PEG-9 is used in cosmetics and pharmaceutical products, its toxicology profile has been studied extensively and no mutagenic or genotoxic effects were found. PEG-9 has very good dermatological properties. When applied to the skin, it does not cause irritation or allergic responses. There is no inflammation or other adverse skin reactions after its application.
