Description: Glycerol is an osmotic dehydrating agent with hygroscopic and lubricating properties which increases plasma osmolality, resulting in the movement of water from extravascular spaces into the plasma through osmosis. It has a demulcent property which possibly blocks sensory cough receptors in the respiratory tract.Synonym: glycerin.Pharmacokinetics:Absorption: Readily absorbed from the gastrointestinal tract (oral). Poorly absorbed (rectal).Metabolism: Extensively metabolised in the liver into glucose or glycogen or oxidised to carbon dioxide and water.Excretion: Mainly via urine, as unchanged drug.