Lanolin (synonyms: wool wax, wool grease, Adeps Lanae) is a purified, waxy, anhydrous substance obtained from the wool of sheep (Ovis aries).
Writing under the name 'Oesypus', in his 5-volume major work 'De Materia medica', the Greek physician and pharmacist Dioskurides (1st. century B.C.) mentions a fatty substance; today, we realise that he was referring to 'wool wax' (lanolin). At that time, lanolin was obtained by boiling sheep wool in water, after which the oily layer floating on the surface was skimmed off. Over the centuries, lanolin lapsed back into obscurity. It was not until 1882 that it was manufactured in purified form by Brown and Liebrich and given its Latin name (taken from lana = wool; Oleum = oil).
In terms of its chemical composition, lanolin is not actually a fat (no fatty acid glycerol ester), but a mixture made up of esters from various acids and alcohols. Lanolin is obtained after shearing by washing the fats out with soap and soda until the required degree of fat removal has been achieved (in premises known as 'wool washeries'), by acidification (precipitation of the waxes), by alkaline emulsification and by centrifugation of the crude, liquid lanolin. This is then purified by re-melting the lanolin several times over and washing it out.
Solid wool wax is a pale yellow substance with the consistency of an ointment and with a characteristic smell. In its molten condition, wool wax is a clear, or virtually clear, yellow liquid that is practically insoluble in water, poorly soluble in ethanol and soluble in ether. Solutions of wool wax in benzine exhibit opalescence. However, the most obvious property of wool wax is its ability to absorb up to 300% water and this is the real reason why it is suitable for use in all sectors of the cosmetics and pharmaceuticals trades.
The resultant emulsions have a very good shelf-life. Kneading the mass has no effect upon its external quality. Lanolin is excellent at penetrating the skin, but lanolin is also a potential irritant and can trigger allergic reactions in sensitive skin. In industry, lanolin is used in the manufacture of textiles and leather goods (greasing agent), also as a rust-proofing agent. Acetylation, ethoxylation and hydroxylation of lanolin make the product suitable for use in the manufacture of other cosmetics.
INCI Name: Lanolin