332 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS alcohols, etc. The so-called wool alcohols represent the unsaponifiable fraction of wool fat, the theoretical yield being about 50% from refined lanolin but varying according to the raw material used and the methods used for saponification, extraction and refining. The physical properties of this refined product also vary according to its previous history, examples of properties affected being-emulsifying power, cholesterol content, hydroxyl value, and to a certain extent, solubility. The product used was produced from anhydrous lanolin of pharmaceutical quality and extracted with trichloroethylene, subsequent refining operations including vacuum- deodorisation and chemical bleaching. The uses of wool alcohols in cosmetics are basically similar to those of lanolin, but the product is much harder, having a brittle waxy consistency as compared to an unctuous grease. Its w/o emulsifying properties are much more powerful than those of the original lanolin. It may be used in pressurized emulsions, or, for example, as a plasticiser or film-modifier in hair sprays. Like lanolin, wool alcohols are insoluble in water, and thus can only be utilised in pressure packs in the form of emulsions or as solutions in organic solvents or in a suitable propellent system. iii. Liquid lanolin "A.C.E." This•is a chemically modified lanolin derivative, consisting of an almost fully acetylated fraction of wool alcohols. It is a clear, moderately viscous fluid, very readily taken up by the skin without any residual stickiness. The product has virtually no emulsifying properties by reason of the blocked hydrophilic groups, but is very emollient, conditions the hair and imparts gloss, and is soluble in, and compatible with, a wide range of products used in cosmetics and pharmacy. iv. Alcohol soluble lanolin Prepared from B.P. quality wool alcohols, and not chemically modified in any way, the physical characteristics of this material are those of a soft, easily melted, orange coloured wax with a faint, characteristic odour. It has a high content of free cholesterol, and is thus a ready means of achieving an alcoholic solution of cholesterol (which itself has limited solubility in cold alcohol) for scalp treatments. Alcohol soluble lanolin still retains some of the powerful w/o emulsifying characteristics of its parent wool alcohols, but is much less efficient and gives less stable emulsions. It is ideal for the preparation of 'alcoholic hair sprays. The product is stabilised during manufacture to be resistant to oxidation, and its films, even when freely exposed to the air, never become brittle or powdery, and

LANOLIN DERIVATIVES FOR PRESSURIZED FORMULATIONS 333 are always easily removed from the hair, if desired, by washing or shampooing. v. Liquid lanolin "50 Super" This is a chemically unmodified fluid fraction of the lanolin esters obtained by physical segregation, similar to the conventional solid lanolin chemically and dermatologically, but in the form of a clear fluid which is more easily applied to, and absorbed by, the skin, and which has better general solubility in organic solvents. vi. Liquid lanolin I.S.O. A blended and oil-solubilised lanolin, it consists of a mixture of 40% unreacted lanolin with free alcohols and isopropy! esters. It is a clear, very mobile, pale yellow liquid soluble in anhydrous ethanol, isopropanol, acetone, mineral oil and many other organic substances, and is valuable in brillian- tines, hair sprays, hand lotions, etc., where the minimum viscosity and the absence of stickiness are important. vii. Liquid lanolin "R.I.C.2" Another blended and oil-solubilised !artolin, it contains 25% of unreacted lanolin together with 25% of ricinoleic esters and free alcohols. It combines the properties of lanolin and castor oil, and is so formulated as to have a wide range of compatibilities with cosmetic ingredients. The product is a clear liquid of low viscosity, is emollient to the skin and gives a good gloss to the hair. viii. Liquid lanolin "L.I.N." This product belongs to the same class as (vi) and (vii) above, and contains 40% of chemically unreacted lanolin with linoleic esters and free alcohols. In physical characteristics it is similar to the I.S.O. grade (vi), but the unsaturated components are valuable for the skin and impart an outstanding gloss to the hair. The odour is faint, the unsaturated note being hardly detectable, and the product is stabilised against auto-oxidation. Products (vi), (vii) and (viii) are characterised by low cloud and pour points. ix. Water soluble lanolin "75" Water soluble lanolin consists of ester/ether compounds resulting from the reaction between the natural esters of which lanolin is composed and