Concept

Lanoline

Résumé

Lanolin (from Latin lāna 'wool', and oleum 'oil'), also called wool yolk, wool wax, or wool grease, is a wax secreted by the sebaceous glands of wool-bearing animals. Lanolin used by humans comes from domestic sheep breeds that are raised specifically for their wool. Historically, many pharmacopoeias have referred to lanolin as wool fat (adeps lanae); however, as lanolin lacks glycerides (glycerol esters), it is not a true fat. Lanolin primarily consists of sterol esters instead. Lanolin's waterproofing property aids sheep in shedding water from their coats. Certain breeds of sheep produce large amounts of lanolin. Lanolin's role in nature is to protect wool and skin from climate and the environment; it also plays a role in skin (integumental) hygiene. Lanolin and its derivatives are used in the protection, treatment, and beautification of human skin. A typical high-purity grade of lanolin is composed predominantly of long chain waxy esters (approximately 97% by weight) with the remainder being lanolin alcohols, lanolin acids and lanolin hydrocarbons. An estimated 8,000 to 20,000 different types of lanolin esters are present in lanolin, resulting from combinations between the 200 or so different lanolin acids and the 100 or so different lanolin alcohols identified so far. Lanolin’s complex composition of long-chain esters, hydroxyesters, diesters, lanolin alcohols, and lanolin acids means in addition to its being a valuable product in its own right, it is also the starting point for the production of a whole spectrum of lanolin derivatives, which possess wide-ranging chemical and physical properties. The main derivatisation routes include hydrolysis, fractional solvent crystallisation, esterification, hydrogenation, alkoxylation and quaternisation. Lanolin derivatives obtained from these processes are used widely in both high-value cosmetics and skin treatment products. Hydrolysis of lanolin yields lanolin alcohols and lanolin acids.

Source officielle

https://fr.wikipedia.org/wiki/Lanoline

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