Ланолин

Химические свойства

Lanolin is a pale yellow-colored, unctuous, waxy substance with a faint, characteristic odor. Melted lanolin is a clear or almost clear, yellow liquid.

Использование

lanolin (hydrogenated) is a lanolin derivative.

Определение

lanolin: An emulsion of purified wool fat in water, containing cholesteroland certain terpene alcoholsand esters. It is used in cosmetics.

Методы производства

Lanolin is a naturally occurring wax-like material obtained from the wool of sheep, Ovis aries Linne′ (Fam. Bovidae).
Crude lanolin is saponified with a weak alkali and the resultant saponified fat emulsion is centrifuged to remove the aqueous phase. The aqueous phase contains a soap solution from which, on standing, a layer of partially purified lanolin separates. This material is then further refined by treatment with calcium chloride, followed by fusion with unslaked lime to dehydrate the lanolin. The lanolin is finally extracted with acetone and the solvent is removed by distillation.

Фармацевтические приложения

Lanolin is widely used in topical pharmaceutical formulations and cosmetics.
Lanolin may be used as a hydrophobic vehicle and in the preparation of water-in-oil creams and ointments. When mixed with suitable vegetable oils or with soft paraffin, it produces emollient creams that penetrate the skin and hence facilitate the absorption of drugs. Lanolin mixes with about twice its own weight of water, without separation, to produce stable emulsions that do not readily become rancid on storage.

Побочные эффекты

Most emollients can be used safely and effectively without side effects. However, burning, stinging, redness or irritation may occur. Rare and very serious allergic reactions are abnormal changes in the skin (e.g., whitening/softening/wetness from over-moisturisation), rashes, itching/swelling (especially on the face/tongue/throat), severe dizziness, and difficulty breathing. If any discomfort occurs, contact your doctor immediately.

Безопасность

Lanolin is widely used in cosmetics and a variety of topical pharmaceutical formulations.
Although generally regarded as a nontoxic and nonirritant material, lanolin and lanolin derivatives are associated with skin hypersensitivity reactions, and the use of lanolin in subjects with known sensitivity should be avoided. Other reports suggest that ‘sensitivity’ arises from false positives in patch testing.However, skin hypersensitivity is relatively uncommon; the incidence of hypersensitivity to lanolin in the general population is estimated to be around 5 per million.
Sensitivity is thought to be associated with the content of free fatty alcohols present in lanolin products rather than the total alcohol content.The safety of pesticide residues in lanolin products has also been of concern. However, highly refined ‘hypoallergenic’ grades of lanolin and grades with low pesticide residues are commercially available.

хранилище

Lanolin may gradually undergo autoxidation during storage. To inhibit this process, the inclusion of butylated hydroxytoluene is permitted as an antioxidant. Exposure to excessive or prolonged heating may cause anhydrous lanolin to darken in color and develop a strong rancidlike odor. However, lanolin may be sterilized by dry heat at 150°C. Ophthalmic ointments containing lanolin may be sterilized by filtration or by exposure to gamma irradiation.

Несовместимости

Lanolin may contain prooxidants, which may affect the stability of certain active drugs.

Регуляторный статус

Included in the FDA Inactive Ingredients Database (ophthalmic, otic, topical, and vaginal preparations). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.