Specification :

PEG 400
Polyethylene glycol
Identifiers
CAS number
25322-68-3

Properties
Molecular formula
C2nH4n+ 2On+ 1, n = 8.2 to 9.1
Molar mass
380-420 g/ mol
Density
1.128 g/ cm³
Melting point
4-8 ° C
Viscosity
90.0 cSt at 25 ° C, 7.3 cSt at 99 ° C
Hazards
Flash point
238 ° C
LD50
30 mL/ kg, orally in rats
Except where noted otherwise, data are given for materials in their standard state ( at 25 ° C, 100 kPa)

PEG 400 ( Polyethylene Glycol 400) is a low molecular weight grade of Polyethylene glycol. 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.
Additional Properties
PEG 400 is strongly hydrophilic. The partition coefficient of polyethylene glycol 414 between hexane and water is 0.000015 ( logP =  4.8) , indicating that when polyethylene glycol 414 is mixed with water and hexane, there are only 1.5 parts of polyethylene glycol 414 in the hexane layer per 100, 000 parts of polyethylene glycol 414 in the water layer. PEG 400 is soluble in water, acetone, alcohols, benzene, glycerin, glycols, aromatic hydrocarbons and is slightly soluble in aliphatic hydrocarbons.
Usage:
PEG400 is better for making the soft gelatin capsules. As the PEG400 is liquid, it has a broad compatibility with various solvents, and is Good solvent and solubilizer.It has been widely used in liquid preparations, such as the oral solution, eye drops etc.