Polyethylene glycol
Polyethylene glycol and polyethylene oxide are polymers of ethylene oxide. Polyethylene glycol refers to the polymer with molecular weight less than 50,000, while polyethylene oxide is used for higher molecular weights.
Polyethylene glycol has the following structure:
- -(CH2-CH2-O)n-
It is soluble in water, methanol, benzene, dichloromethane and is insoluble in diethyl ether and hexane.
Polyethylene glycol is coupled to hydrophobic molecules to produce non-ionic surfactants.
Uses
Polyethylene glycol is non-toxic and is used in a variety of products. In fact, it is the basis of a number of laxatives (e.g. macrogol-containing products such as Movicol®). As cetomacrogol it is the basis of many skin creams. Additionally, PEG added to recombinant peptide hormones decreases their half-life and increasing dosage intervals; examples are PEG-interferon alpha (as used in hepatitis C) and PEG-filgrastim (Neulasta®).
