Lanolin is a waxy fat substance extracted from the sebaceous glands of sheep. Lanolin is often likened to human sebum due to its unique chemical composition, allowing it to act as an excellent moisturizer.

Origin and extraction. Lanolin is derived by washing raw sheep's wool with water and detergent. During this process, lanolin is separated from the wool and purified through various methods.

Raw materials in the production of Lanolin.

• Sheep's wool. Lanolin is a fat derived from the wool of sheep.

Step-by-step summary of industrial chemical synthesis process:

• Harvesting the wool. Sheep are sheared to collect their wool.
• Washing and purification. The wool is washed in hot water with detergents to remove dirt and impurities.
• Separation of lanolin. During the washing process, lanolin separates from the wool and floats on the water due to its oily nature.
• Refinement. The crude lanolin is further treated and purified through various processes, including centrifugation, to remove impurities.
• Decolorization and deodorization. The lanolin may be treated to remove unwanted colors and odors.
• Quality control and packaging. The lanolin is tested to ensure it meets quality standards. Once approved, it's packaged and prepared for shipment.

Primary Uses. Lanolin is widely used in cosmetics, skin, and hair products. Owing to its emollient and moisturizing properties, it's frequently found in hand creams, lip balms, lotions, and body creams.

Skin benefits. Being a natural humectant, lanolin aids in retaining water in the skin, preventing dehydration and providing a softening effect.

Cosmetics

Antistatic agent. Static electricity build-up has a direct influence on products and causes electrostatic adsorption. The antistatic ingredient reduces static build-up and surface resistivity on the surface of the skin and hair.

Skin conditioning agent - Emollient. Emollients have the characteristic of enhancing the skin barrier through a source of exogenous lipids that adhere to the skin, improving barrier properties by filling gaps in intercorneocyte clusters to improve hydration while protecting against inflammation. In practice, they have the ability to create a barrier that prevents transepidermal water loss.  Emollients are described as degreasing or refreshing additives that improve the lipid content of the upper layers of the skin by preventing degreasing and drying of the skin. The problem with emollients is that many have a strong lipophilic character and are identified as occlusive ingredients; they are oily and fatty materials that remain on the skin surface and reduce transepidermal water loss. In cosmetics, emollients and moisturisers are often considered synonymous with humectants and occlusives.

Surfactant - Emulsifying agent. Emulsions are thermodynamically unstable and are used to soothe or soften the skin and emulsify, so they need a specific, stabilising ingredient. This ingredient forms a film, lowers the surface tension and makes two immiscible liquids miscible. A very important factor affecting the stability of the emulsion is the amount of the emulsifying agent. Emulsifiers have the property of reducing the oil/water or water/oil interfacial tension, improving the stability of the emulsion and also directly influencing the stability, sensory properties and surface tension of sunscreens by modulating the filmometric performance.

Hair conditioning agent. A significant number of ingredients with specific and targeted purposes may co-exist in hair shampoo formulations: cleansers, conditioners, thickeners, matting agents, sequestering agents, fragrances, preservatives, special additives. However, the indispensable ingredients are the cleansers and conditioners as they are necessary and sufficient for hair cleansing and manageability. The others act as commercial and non-essential auxiliaries such as: appearance, fragrance, colouring, etc. Hair conditioning agents have the task of increasing shine, manageability and volume, and reducing static electricity, especially after treatments such as colouring, ironing, waving, drying and brushing. They are, in practice, dispersants that may contain cationic surfactants, thickeners, emollients, polymers. The typology of hair conditioning agents includes: intensive conditioners, instant conditioners, thickening conditioners, drying conditioners. They can perform their task generally accompanied by other different ingredients.

Skin conditioning agent. It is the mainstay of topical skin treatment as it has the function of restoring, increasing or improving skin tolerance to external factors, including melanocyte tolerance. The most important function of the conditioning agent is to prevent skin dehydration, but the subject is rather complex and involves emollients and humectants that can be added in the formulation.

Surfactant - Cleansing agent. Cosmetic products used to cleanse the skin utilise the surface-active action that produces a lowering of the surface tension of the stratum corneum, facilitating the removal of dirt and impurities. 

Commercial Applications

Cosmetic and Skin Care Products. Lanolin is widely used in creams, lotions, and lip balms as a moisturizing and emollient agent.

Hair Products. Used in shampoos and conditioners for its conditioning properties.

Foot Care Products. Often found in foot creams to treat and prevent cracked heels.

Leather Industry. Used as a conditioner and waterproofing agent.

Medical Applications

Emollient in Medicine. Used in creams and ointments to treat dry and chapped skin and for transdermal permeation (1).

Nipple Care and Protection. Lanolin-based creams are recommended for breastfeeding mothers to prevent and treat chapped nipples.

Varieties. There are various forms of lanolin, including anhydrous lanolin and hydrolyzed lanolin. Anhydrous lanolin is devoid of water, whereas hydrolyzed lanolin has undergone a process making it more water-soluble.

Safety

 Some individuals might be allergic or sensitive to lanolin (2) and could develop skin reactions upon its application. It's always advisable to perform a patch test before using products containing lanolin, especially if one has sensitive skin.

References_____________________________________________________________________

(1) Alonso C, Collini I, Martí M, Barba C, Coderch L. Lanolin-Based Synthetic Membranes for Transdermal Permeation and Penetration Drug Delivery Assays. Membranes (Basel). 2021 Jun 15;11(6):444. doi: 10.3390/membranes11060444. PMID: 34203604; PMCID: PMC8232266.

Abstract. Due to the high similarity in composition and structure between lanolin and human SC lipids, we will work with two models from wool wax. Two types of lanolin were evaluated: one extracted with water and surfactants (WEL) and the other extracted with organic solvents (SEL). Skin permeation and skin penetration studies were performed with two active compounds to study the feasibility of the use of lanolin-based synthetic membranes as models of mammalian skin. Diclofenac sodium and lidocaine were selected as the active compounds considering that they have different chemical natures and different lipophilicities. In the permeation assay with SEL, a better correlation was obtained with the less permeable compound diclofenac sodium. This assay suggests the feasibility of using artificial membranes with SEL as a model for percutaneous absorption studies, even though the lipophilic barrier should be improved. Penetration profiles of the APIs through the SEL and WEL membranes indicated that the two membranes diminish penetration and can be considered good membrane surrogates for skin permeability studies. However, the WEL membranes, with a pH value similar to that of the skin surface, promoted a higher degree of diminution of the permeability of the two drugs, similar to those found for the skin.

(2) Lee B, Warshaw E. Lanolin allergy: history, epidemiology, responsible allergens, and management. Dermatitis. 2008 Mar-Apr;19(2):63-72. PMID: 18413106.

Abstract. Allergy to lanolin has been recognized by dermatologists for decades. This review summarizes the history, epidemiology, and allergenicity of lanolin and its derivatives. "The lanolin paradox" and the safety of pharmaceutical-grade lanolin products are also discussed.