A demulcent (derived from the Latin: demulcere "caress") is an agent that forms a soothing film over a mucous membrane, relieving minor pain and inflammation of the membrane. However, they generally help for less than 30 minutes.Demulcents are sometimes referred to as mucoprotective agents. Demulcents such as pectin, glycerin, honey, and syrup are common ingredients in cough mixtures and cough drops. Methylcellulose, propylene glycol, and glycerine are synthetic demulcents.