Sorbitan is a mixture of chemical compounds derived from the dehydration of sorbitol. The mixture can vary, but usually consists of 1,4-anhydrosorbitol, 1,5-anhydrosorbitol and 1,4,3,6-dianhydrosorbitol. Sorbitan is primarily used in the production of surfactants such as polysorbates. Sorbitan esters ( also known as Spans ) are lipophilic non ionic surfactants that are used as emulsifying agents in the preparation of emulsions, creams, and ointments for pharmaceutical and cosmetic use. When used alone they produce stable water-in-oil emulsions but they are frequently used with a polysorbate (aslo known as Tweens) in varying proportions to produce water-in-oil or oil-in-water emulsions or creams with a variety of different textures and consistencies. Sorbitan esters are also used as emulsifiers and stabilisers in food.