PEG 400 (polyethylene glycol 400) is a low-molecular-weight grade of
polyethylene glycol
Polyethylene glycol (PEG; ) is a polyether compound derived from petroleum with many applications, from industrial manufacturing to medicine. PEG is also known as polyethylene oxide (PEO) or polyoxyethylene (POE), depending on its molecular we ...
. It is a clear, colorless, viscous liquid. Due in part to its low toxicity, PEG 400 is widely used in a variety of pharmaceutical formulations.
Chemical properties
PEG 400 is strongly
hydrophilic
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press.
In contrast, hydrophobes are n ...
. The
partition coefficient
In the physical sciences, a partition coefficient (''P'') or distribution coefficient (''D'') is the ratio of concentrations of a compound in a mixture of two immiscible solvents at equilibrium. This ratio is therefore a comparison of the solub ...
of PEG 400 between hexane and water is 0.000015 (log
), indicating that when PEG 400 is mixed with water and hexane, there are only 15 parts of PEG400 in the hexane layer per 1 million parts of PEG 400 in the water layer.
PEG 400 is soluble in water, acetone, alcohols, benzene, glycerin, glycols, and aromatic hydrocarbons, and is slightly soluble in aliphatic hydrocarbons.
References
{{reflist
*The Merck Index, 11th Edition
*Handbook of Pharmaceutical Excipients
Polyethers