Home      Discussion      Topics      Dictionary      Almanac
Signup       Login
Lanolin

Lanolin

Overview
Lanolin also called Adeps Lanae, wool wax or wool grease, is a yellow waxy substance secreted by the sebaceous gland
Sebaceous gland
The sebaceous glands are microscopic glands in the skin that secrete an oily/waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals...

s of wool-bearing
Wool
Wool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....

 animals. Most lanolin used by humans comes from domestic sheep
Domestic sheep
Sheep are quadrupedal, ruminant mammals typically kept as livestock. Like all ruminants, sheep are members of the order Artiodactyla, the even-toed ungulates. Although the name "sheep" applies to many species in the genus Ovis, in everyday usage it almost always refers to Ovis aries...

. Lanolin is also frequently, but incorrectly, referred to as ‘Wool Fat’ by many of the world’s pharmacopoeia
Pharmacopoeia
Pharmacopoeia, pharmacopeia, or pharmacopoea, , in its modern technical sense, is a book containing directions for the identification of samples and the preparation of compound medicines, and published by the authority of a government or a medical or pharmaceutical society.In a broader sense it is...

s even though it has been known for more than 150 years that lanolin is devoid of glycerides and is in fact a wax
Wax
thumb|right|[[Cetyl palmitate]], a typical wax ester.Wax refers to a class of chemical compounds that are plastic near ambient temperatures. Characteristically, they melt above 45 °C to give a low viscosity liquid. Waxes are insoluble in water but soluble in organic, nonpolar solvents...

, not a fat.
Discussion
Ask a question about 'Lanolin'
Start a new discussion about 'Lanolin'
Answer questions from other users
Full Discussion Forum
 
Recent Discussions
Encyclopedia
Lanolin also called Adeps Lanae, wool wax or wool grease, is a yellow waxy substance secreted by the sebaceous gland
Sebaceous gland
The sebaceous glands are microscopic glands in the skin that secrete an oily/waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals...

s of wool-bearing
Wool
Wool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....

 animals. Most lanolin used by humans comes from domestic sheep
Domestic sheep
Sheep are quadrupedal, ruminant mammals typically kept as livestock. Like all ruminants, sheep are members of the order Artiodactyla, the even-toed ungulates. Although the name "sheep" applies to many species in the genus Ovis, in everyday usage it almost always refers to Ovis aries...

. Lanolin is also frequently, but incorrectly, referred to as ‘Wool Fat’ by many of the world’s pharmacopoeia
Pharmacopoeia
Pharmacopoeia, pharmacopeia, or pharmacopoea, , in its modern technical sense, is a book containing directions for the identification of samples and the preparation of compound medicines, and published by the authority of a government or a medical or pharmaceutical society.In a broader sense it is...

s even though it has been known for more than 150 years that lanolin is devoid of glycerides and is in fact a wax
Wax
thumb|right|[[Cetyl palmitate]], a typical wax ester.Wax refers to a class of chemical compounds that are plastic near ambient temperatures. Characteristically, they melt above 45 °C to give a low viscosity liquid. Waxes are insoluble in water but soluble in organic, nonpolar solvents...

, not a fat. Lanolin's waterproofing property aids sheep in shedding water from their coats. Certain breeds of sheep produce large amounts of lanolin, and the extraction can be performed by squeezing the sheep's harvested wool between rollers. Most or all of the lanolin is removed from wool when it is processed into textiles, such as yarn
Yarn
Yarn is a long continuous length of interlocked fibres, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery and ropemaking. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or...

 or felt
Felt
Felt is a non-woven cloth that is produced by matting, condensing and pressing woollen fibres. While some types of felt are very soft, some are tough enough to form construction materials. Felt can be of any colour, and made into any shape or size....

.

Lanolin's role in nature is to protect wool and skin against the ravages of climate and the environment – it also seems to play a role in integumental
Integumentary system
The integumentary system is the organ system that protects the body from damage, comprising the skin and its appendages...

 hygiene. It is therefore not surprising that lanolin and its many derivatives are used extensively in products designed for the protection, treatment and beautification of human skin.

Composition


Like many natural products, lanolin has a complex and variable composition. For example, a typical high purity grade of lanolin is composed predominantly of long chain waxy ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

s (ca. 97% by weight) the remainder being lanolin alcohols, lanolin acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

s and lanolin hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

s.

It has been estimated that there may be between 8,000 and 20,000 different types of lanolin ester present in lanolin resulting from combinations between the ca. 200 different lanolin acids and the ca. 100 different lanolin alcohols that have so far been identified.

Lanolin's complex composition of long chain esters, hydroxy esters, diesters, lanolin alcohols, lanolin acids means that in addition to it 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
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...

, fractional solvent crystallisation, esterification, hydrogenation
Hydrogenation
Hydrogenation, to treat with hydrogen, also a form of chemical reduction, is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically...

, alkoxylation and quaternisation Lanolin derivatives obtained from these processes are used widely in both high-value cosmetic
Cosmetics
Cosmetics are substances used to enhance the appearance or odor of the human body. Cosmetics include skin-care creams, lotions, powders, perfumes, lipsticks, fingernail and toe nail polish, eye and facial makeup, towelettes, permanent waves, colored contact lenses, hair colors, hair sprays and...

 and skin treatment
Dermatology
Dermatology is the branch of medicine dealing with the skin and its diseases, a unique specialty with both medical and surgical aspects. A dermatologist takes care of diseases, in the widest sense, and some cosmetic problems of the skin, scalp, hair, and nails....

 products.

Hydrolysis
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...

 of lanolin yields lanolin alcohols and lanolin acids. Lanolin alcohols are a rich source of cholesterol
Cholesterol
Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...

 (an important skin lipid) and are powerful water-in-oil emulsifiers; they have been used extensively in skin care products for over 100 years. Interestingly, approximately 40% of the acids derived from lanolin are alpha hydroxy acid
Alpha hydroxy acid
α-Hydroxy acids, or alpha hydroxy acids , are a class of chemical compounds that consist of a carboxylic acid substituted with a hydroxyl group on the adjacent carbon. They may be either naturally occurring or synthetic. AHAs are well-known for their use in the cosmetics industry...

s. The use of alpha hydroxy acids (AHA’s) in skin care products has attracted a great deal of attention in recent years. Details of the AHA’s isolated from lanolin can be seen in the table below.
Type of lanolic acid Carbon chain length Number identified
Alpha hydroxy normal C13 – C24 12
Alpha hydroxy iso C13 – C23 6
Alpha hydroxy anteiso C12 – C24 7

Modern developments


In addition to general purity requirements, there are now official requirements for the level of pesticide residues permissible in lanolin. The 5th Supplement of the United States Pharmacopoeia XXII published in 1992 was the first to specify limits for 34 named pesticide
Pesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...

s. A total limit of 40 p.p.m. (40 mg kg−1) total pesticides was stipulated for lanolin of general use, with no individual limit greater than 10 p.p.m. (10 mg kg−1).

A second monograph also introduced into the United States Pharmacopoeia XXII in 1992 was entitled 'Modified Lanolin.' Lanolin conforming to this monograph is intended for use in more exacting applications, for example on open wounds. In the Modified Lanolin monograph, the limit of total pesticides is reduced to 3 p.p.m. (3 mg kg−1) total pesticides with no individual limit greater than 1 p.p.m. (1 mg kg−1).

In 2000, the European Pharmacopoeia introduced pesticide residue limits into its lanolin monograph. This requirement, which is generally regarded as the new quality standard, extends the list of pesticides to 40 and imposes even lower concentration limits.

However, some very high purity grades of lanolin surpass monograph requirements. New products obtained using complex purification techniques produce lanolin esters in their natural state removing oxidative and environmental impurities resulting in white, odourless, hypoallergenic
Hypoallergenic
Hypoallergenic, meaning "below normal" or "slightly" allergenic, was a term first used in a cosmetics campaign in 1953. It is used to describe items that cause or are claimed to cause fewer allergic reactions...

 lanolin. These ultra-high purity grades of lanolin are ideally suited to the treatment of dermatological disorders such as eczema
Eczema
Eczema is a form of dermatitis, or inflammation of the epidermis . In England, an estimated 5.7 million or about one in every nine people have been diagnosed with the disease by a clinician at some point in their lives.The term eczema is broadly applied to a range of persistent skin conditions...

 and on open wounds.

Some years ago, lanolin attracted a great deal of attention owing to a misunderstanding concerning its sensitising potential. A study carried out at New York University Hospital in the early 1950s had shown that approximately 1% of patients with dermatological disorders were allergic to the lanolin being used at that time. However, this figure was misinterpreted and taken out of context and became quoted as 1% of the general healthy (American) population. It has been estimated that this simple misunderstanding by failing to differentiate between the general healthy population and patients with dermatological disorders exaggerates the sensitising potential of lanolin by approximately 5,000 – 6,000 times.

By the time the European Cosmetics Directive
Cosmetics Directive
Council Directive 76/768/EEC of 1976-07-27 on the approximation of the laws of the Member States relating to cosmetic products is the main European Union law on the safety of cosmetics. It was made under Art. 100 of the Treaty of Rome...

 was introduced in July 1976, there had been so much adverse (but completely unfounded) publicity concerning lanolin that it contained a stipulation that cosmetics which contained lanolin should be labelled to that effect. This ruling was challenged immediately and in the early 1980s it was overturned and removed from the Directive. Despite only being in force for a very short period of time this ruling did a great deal of harm both to the lanolin industry and to the reputation of lanolin in general. The irony is that the Cosmetics Directive ruling only applied to the presence of lanolin in cosmetic products – it did not apply to the many hundreds of different lanolin derivatives used in cosmetic products or to the use lanolin in dermatological products designed for the treatment of compromised skin conditions.

However, lanolin's safety and efficacy is probably best illustrated taking a look at the market. High lanolin content baby care products (some as high as 100%) and treatment products for nursing mothers are commonplace.

More recently, using modern scientific methods, attention has focused on the positive aspects of lanolin and on increasing our understanding about how lanolin achieves its beneficial skin effects.

Modern analytical methods have revealed that lanolin possesses a number of important chemical and physical similarities to human stratum corneum
Stratum corneum
The stratum corneum is the outermost layer of the epidermis, consisting of dead cells that lack nuclei and organelles. The purpose of the stratum corneum is to form a barrier to protect underlying tissue from infection, dehydration, chemicals and mechanical stress...

 lipids; the lipids which help regulate the rate of trans-epidermal water loss and govern the hydration state of the skin.

Cryo-scanning electron microscopy has shown that lanolin, like human stratum corneum lipids, consists of a mass of liquid crystalline material. Cross-polarised light microscopy has shown the multi-lamellar vesicle
Vesicle (biology)
A vesicle is a bubble of liquid within another liquid, a supramolecular assembly made up of many different molecules. More technically, a vesicle is a small membrane-enclosed sack that can store or transport substances. Vesicles can form naturally because of the properties of lipid membranes , or...

s formed by lanolin are identical to those formed by human stratum corneum lipids. It is well known that the incorporation of bound water into the stratum corneum involves the formation of multi-lamellar vesicles.

Skin bio-engineering studies have shown that the durational effect of the emollient (skin smoothing) action produced by lanolin is very significant and lasts for many hours. Lanolin applied to the skin at 2mg cm−2 has been shown to reduce roughness by ca. 35% after 1 hour and ca. 50% after 2 hours with the overall lasting for considerably more than 8 hours. Lanolin is also known to form semi-occlusive (i.e. breathable) films on the skin. When applied daily at ca. 4 mg cm−2 for five consecutive days, the positive moisturising effects of lanolin were detectable until ca. 72 hours after final application. It has been postulated that lanolin may achieve some of its moisturising effects forming a secondary moisture reservoir within the skin.

In other studies, the barrier repair properties of lanolin have been reported to be superior to those produced by both petrolatum and glycerin. In a small clinical study conducted on volunteer subjects with terribly dry (xerotic) hands, lanolin was shown to be superior to Petrolatum in reducing the signs and symptoms of dryness and scaling, cracks and abrasions, and pain and itch. In another study, a high purity grade of lanolin was found to be significantly superior to Petrolatum in assisting the healing of superficial wounds.

Applications



Lanolin and its many derivatives are used extensively in both the personal care (e.g. in high value cosmetics, facial cosmetics, lip products etc.) and health care sectors. Lanolin is frequently used in protective baby skin treatment (and nursing mother) markets.

Lanolin is used commercially in many industrial products ranging from rust
Rust
Rust is a general term for a series of iron oxides. In colloquial usage, the term is applied to red oxides, formed by the reaction of iron and oxygen in the presence of water or air moisture...

-proof coatings to lubricant
Lubricant
A lubricant is a substance introduced to reduce friction between moving surfaces. It may also have the function of transporting foreign particles and of distributing heat...

s. Some sailors use lanolin to create a slippery surface on their propeller
Propeller
A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's...

s and stern gear to which barnacles cannot adhere. The water-repellent properties make it valuable as a lubricant grease where corrosion
Corrosion
Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...

 would otherwise be a problem.

Lanolin is often used as a raw material for producing cholecalciferol
Cholecalciferol
Cholecalciferol is a form of vitamin D, also called vitamin D3 or calciol.It is structurally similar to steroids such as testosterone, cholesterol, and cortisol .-Forms:Vitamin D3 has several forms:...

 (vitamin D3).

Lanolin is often used by baseball players to soften and break in their baseball glove
Baseball glove
A baseball glove or mitt is a large leather glove that baseball players on the defending team are allowed to wear to assist them in catching and fielding balls hit by a batter, or thrown by a teammate.-History:...

s (shaving cream that contains lanolin is popularly used for this).

Anhydrous
Anhydrous
As a general term, a substance is said to be anhydrous if it contains no water. The way of achieving the anhydrous form differs from one substance to another...

 lanolin is also used as a lubricant for brass instrument
Brass instrument
A brass instrument is a musical instrument whose sound is produced by sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips...

 tuning slides.

Lanolin can also be restored to wool
Wool
Wool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....

en garments to make them water and dirt repellent, such as for cloth diaper covers.

A flaxseed oil-based lubricant commonly known as "wool wax" used to polish wood furniture is unrelated to lanolin; its name comes from its being a paste wax applied using steel wool
Steel wool
Steel wool, also known as wire wool, is a bundle of strands of very fine soft steel filaments, used in finishing and repairing work to polish wood or metal objects, and for cleaning household cookware....

.

Lanolin is also used in lip balm products such as Carmex
Carmex
Carmex is a brand of lip balm meant to eliminate cold sores and soothe dry/chapped lips. It is sold in jars, sticks, and squeezable tubes.-History:...

. For some people Lanolin can irritate the lips .

Production


Crude lanolin constitutes approximately 5–25% of the weight of freshly shorn wool. The wool from one Merino sheep will produce about 250–300 ml of recoverable wool grease. Lanolin is extracted by washing the wool in hot water with a special wool scouring detergent to remove dirt, wool grease (crude lanolin), suint (sweat salts), and anything else stuck to the wool. The wool grease is continuously removed during this washing process by centrifugal
Centrifuge
A centrifuge is a piece of equipment, generally driven by an electric motor , that puts an object in rotation around a fixed axis, applying a force perpendicular to the axis...

separators, which concentrate the wool grease into a wax-like substance melting at approximately 38 °C (100 °F).

External links