Polyethylene Glycol (PEG) is a synthetic, water-soluble polymer that is widely used in various fields, including pharmaceuticals, cosmetics, and industrial applications. As a result of its versatility and unique chemical properties, PEG has become a popular tool in drug research and development.
PEG is a polyether compound that is made up of repeating ethylene oxide units, giving it a hydrophilic character. The polymer can vary in size, with a range of molecular weights, and can be functionalized with various chemical groups, including hydroxyl, amine, carboxyl, and thiol groups.
In drug research and development, PEG is often used as a drug delivery vehicle due to its ability to improve solubility, stability, and bioavailability of drugs. PEGylation, the process of attaching PEG chains to drugs or biologics, can also increase their circulation time in the body and reduce immunogenicity.
The classification of PEG is based on its molecular weight, which is determined by the number of repeating units. Low molecular weight PEGs (LMW-PEGs) have molecular weights less than 10,000 Da and are used as solubilizing agents or in cosmetic applications. Medium molecular weight PEGs (MMW-PEGs) have molecular weights between 10,000 and 100,000 Da and are commonly used in drug delivery. High molecular weight PEGs (HMW-PEGs) have molecular weights greater than 100,000 Da and are used as lubricants, mold release agents, and in other industrial applications.