Lanolin

LANOLIN, Lanolinum, Adeps lanae, Oesypum, wool fat. Sheep's wool contains a fat-like substance that was known even to the ancient Greeks and Romans under the name Oesypum and was used by them as a medicinal and cosmetic remedy. Initially, unrefined lanolin was produced in southern Germany for medical purposes, and only Liebreich (1885) undertook the preparation and study of pure lanolin. Liebreich also introduced it into dermatology. Lanolin represents the fatty part of the "wool sweat" of sheep. Crude lanolin is obtained by washing sheep's wool with weak alkalis in wool-washing plants and consists of a mixture of lanolin, free fatty acids, and soap. For purification, this mass is treated with alkali, the resulting emulsion is centrifuged, the layer containing lanolin is separated, and it is treated with calcium chloride to bind the free fatty acids. Finally, lanolin is dehydrated by fusing it with marble lime, dissolved in acetone, filtered, and the acetone is distilled off. The resulting pure anhydrous lanolin, Lanolinum purum anhydricum (State Pharmacopoeia VII), consists of a mixture of various esters of cholesterol (C₂₇H₄₅OH), isocholesterol [C₂₇H₄₄(OH)₂], cetyl alcohol (C₂₆H₅₃OH), carnaubyl alcohol (C₂₄H₄₉OH), and cerotic acid (C₂₆H₅₂O₂), lanoceric acid anhydride (C₃₀H₆₀O₄), palmitic acid (C₁₆H₃₂O₂), stearic acid (C₁₈H₃₆O₂), and others. Lanolin is a light yellow, translucent, thick, viscous mass of dense ointment consistency, with a neutral reaction; melting point 38-42°. Lanolin is easily soluble in ether, gasoline, acetone, chloroform, carbon disulfide, sparingly in alcohol, insoluble in water, but combines with almost double its amount of water to form a homogeneous mass. Lanolin is almost un-saponifiable and does not turn rancid. Iodine value 25.6-28.0. Hydrous lanolin, Lanolinum hydricum, Adeps Lanae cum aqua (State Pharmacopoeia VII) contains 70% lanolin and 30% water; it is a yellowish-white ointment that melts on a water bath, separating into 2 layers: the upper is oily, fat-like; the lower is aqueous. Hydrous and anhydrous lanolin are a good base for ointments and cosmetic products and are used for this purpose by themselves or in a mixture with other vegetable fats or liquid petrolatum, because lanolin is well absorbed by the skin and thus not only exerts a direct softening effect on the skin, but also serves as a vehicle for other drugs dissolved or mixed with it. Lanolin is neutral, does not turn rancid, represents an unfavorable medium for the development of microorganisms, does not irritate the skin, and retains a large amount of water; even fats and wax mixed with lanolin also retain a significant amount of water, which is why lanolin serves as a good base for cooling ointments. The addition of vegetable oil or liquid petrolatum to anhydrous or hydrous lanolin makes lanolin softer. Technical lanolin is used for the preparation of ointments in veterinary medicine, compositions for softening leather goods, etc. — Preparations: Lovan, Lovan, an ointment base containing lanolin and mineral oils; Lovan is capable of absorbing up to 300% water. — Eucerin, Eucerin, consists of 5% oxycholesterol isolated from lanolin, 95% paraffin ointment (Unguentum Paraffini), and an equal amount of water; a good ointment base. — Octalin represents lanolin irradiated with ultraviolet rays; under their action, cholesterol and its derivatives are converted into vitasterin with its stimulating effect on biological processes. It is used as an ointment base. — Laneps, Laneps, a lanolin surrogate consisting of aromatic hydrocarbons and a fat-like substance. In appearance it resembles lanolin, absorbs a significant amount of water, and serves as an ointment base.