Polyethylene glycol (PEG) is a polyether compound with a wide range of molecular weights and chemical structures. It is a water-soluble, biocompatible, and non-toxic polymer. PEG is widely used in pharmaceutical formulations, cosmetics, personal care products, and in industries such as textiles, paints, and adhesives.

PEG has many applications, including as a solubilizing agent, a lubricant, a thickener, and an emulsifier in various formulations. In the pharmaceutical industry, PEG is used as a excipient in the formulation of tablets, capsules, and ointments. It is also used as a polymeric carrier for drug delivery systems. In cosmetics and personal care products, PEG is commonly found in shampoos, lotions, and sunscreens as a moisturizing agent and emulsifier.

PEG is synthesized by the polymerization of ethylene oxide and is available in various grades depending on the molecular weight and degree of polymerization. The low molecular weight PEGs are liquid, while the high molecular weight PEGs are waxy solids.