Lanolin does not have a specific molecular target like a receptor or enzyme. Its mechanism of action is primarily physical and based on its emollient and occlusive properties. As an emollient, it softens the skin by filling the spaces between skin cells and creating a smooth surface. As an occlusive agent, it forms a hydrophobic film on the skin's surface that reduces transepidermal water loss, thereby hydrating the skin and protecting it from external irritants. Its complex lipid composition closely resembles human sebum, contributing to its excellent skin compatibility and moisturizing effects.

In vitro, lanolin's activity is assessed by its ability to moisturize and protect the skin in various test systems. Its efficacy is often evaluated using skin models, where its ability to increase skin hydration, reduce water loss, and improve skin barrier function is measured. It is also tested for its skin compatibility and potential to cause irritation or sensitization in cell culture models. As a complex natural mixture, its activity is the sum of its components rather than a single defined molecule.

In vivo, lanolin is used topically for its moisturizing and protective effects on the skin. It is applied to treat painful, cracked nipples during breastfeeding, and to help prevent and treat diaper dermatitis. It is also used to relieve dryness and irritation of the skin in various conditions. When mixed with olive oil, lanolin has shown significant protective effects against dermatitis caused by mineral oil. These in vivo uses are well-established in clinical and consumer settings.

Non-cell-based assays for lanolin are not typical, as it is not a drug that interacts with a specific enzyme or receptor. However, its physical and chemical properties, such as its melting point, acid value, saponification value, and iodine value, are measured to assess its quality and purity according to pharmacopoeial standards. Its composition is analyzed using techniques like gas chromatography (GC) and high-performance liquid chromatography (HPLC) to quantify its various components.

Cellular assays for lanolin typically involve skin cell lines, such as keratinocytes or fibroblasts, to assess its cytotoxicity, irritation potential, and effects on cell proliferation and differentiation. The compound is applied to cultured cells, and markers of cell viability, inflammation, and barrier function are measured. These assays help evaluate the safety and biocompatibility of lanolin for topical applications.

In vivo animal models for lanolin are not commonly used for research purposes, as its effects are well-established in humans. However, animal models of skin irritation or dermatitis may be used to evaluate the protective effects of lanolin-containing formulations. In these models, the compound is applied topically, and skin hydration, redness, and inflammation are assessed.

Lanolin is a complex mixture with a variable composition depending on the source and processing. Its CAS number is 8006-54-0. It is a yellow, waxy solid that is insoluble in water but soluble in organic solvents. It has a melting point in the range of 36-42°C. Lanolin is typically stored in a cool, dry place, protected from light and air to prevent oxidation. For research, it is often supplied as a solid or in a suitable solvent like DMSO.

Effects During Pregnancy and Lactation
◉ Overview of Use During Lactation Lanolin is a yellow fat extracted from wool. Traditionally, it has been used topically to treat nipple pain and cracking during lactation. High-purity lanolin products (e.g., HPA Lanolin, Lansonol) remove pesticide and detergent residues and reduce the content of natural free alcohols to below 1.5% to improve safety and reduce sensitization. However, even with high-purity lanolin, patients with known wool allergies should avoid its use. Lanolin appears to be effective in preventing and treating nipple pain during lactation, but it should not be used as a prenatal preventative medication. Most studies (using Lansonol) have found no significant difference in efficacy between lanolin and applying breast milk, hydrogel dressings, menthol gel, aloe vera, or hot compresses. One meta-analysis concluded that not applying any medication or applying breast milk directly may be superior to lanolin, but high-quality research is lacking. A small, non-blinded study found that olive oil was superior to lanolin in preventing nipple pain; another small, single-blind study found that applying lanolin to painful nipples did not relieve nipple pain compared to routine care. A study of women with nipple trauma and pain compared the effects of applying lanolin after each breastfeeding session with applying breast milk and a nipple shield, finding that breast milk and a nipple shield were more effective than lanolin. A randomized study of 180 mothers compared high-purity lanolin (Lansinoh) and expressed breast milk, finding that lanolin was superior to breast milk in reducing pain and lowering nipple trauma scores over a 7-day study. Two moderate-quality studies found that aloe vera and purslane were more effective than lanolin in treating nipple pain during lactation. A study comparing various high-purity lanolin products found that HPA lanolin (Lansinoh Laboratories Inc.), Purelan (Medela AG), and two lanolin components compliant with EU monographs (Pharmalan PH EU-SO-(RB) and Corona-8 SO-(RB) (Croda, UK)) had the lowest contaminant levels. The components compliant with EU monographs had the lowest contaminant levels. HPA lanolin had extremely low levels of free lanolin alcohol, indicating high purity, four times lower than Purelan. No pesticide residues were detected in HPA lanolin. Purelan contained several pesticide residues (diazinon, synergist, flufenoxuron), but in very low amounts, within permissible limits. ◉ Effects on breastfed infants
As of the revision date, no relevant published information was found.
◉ Effects on Lactation and Breast Milk
In a randomized, double-blind trial, researchers compared the efficacy of lanolin with a general-purpose nipple ointment containing 1% mupirocin, 0.05% betamethasone, and 2% miconazole in reducing nipple pain during the first two weeks postpartum. Both treatments were comparable in reducing nipple pain, shortening nipple healing time, prolonging breastfeeding duration, increasing exclusive breastfeeding rates, reducing mastitis and nipple symptoms, reducing side effects, and improving maternal satisfaction with treatment.
A randomized trial of lanolin with nipple injury and pain compared the effects of routine care to conventional care. Routine care included various methods such as healthcare professional education or assistance, hot and cold compresses, analgesics, air drying of the nipples, or the use of a nursing bra. An observer unaware of the group assignments contacted the mothers several times postpartum by phone to assess healing. After randomization, there was no difference in nipple pain severity between the two groups within 4 to 7 days post-randomization. Four days after randomization, there was no difference in breastfeeding self-efficacy between the two groups; at 4 and 12 weeks postpartum, there was also no difference in breastfeeding rates between the two groups. Women receiving lanolin treatment had higher satisfaction with care.
Lanolin is generally recognized as safe (GRAS) for use in cosmetics and pharmaceutical products. However, it can cause allergic contact dermatitis in some individuals due to the presence of residual pesticides, wool alcohols, or other impurities. High-purity, hypoallergenic lanolin products are available to minimize this risk. The compound is for research use only and standard laboratory safety precautions should be followed when handling it.

[1]. Lanolin. Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006.

Palmitate stearate is a white crystalline or flaky substance. (NTP, 1992)
Palmitate stearate is a palmitic ester formed by the condensation of the carboxyl group of palmitic acid with the hydroxyl group of stearyl alcohol. It is a cosmetic and coral metabolite. It is a hexadecanoate and wax ester. Its function is related to octadecyl-1-ol.
Lanolin has been reported in kapok and wheat, and relevant data are available.
See also: Lanolin (note moved to).
Lanolin is also known as wool fat, wool wax, and wool grease. It is a natural emollient and skin protectant used in a wide variety of creams, ointments, and cosmetics. Its primary function is to hydrate and soften the skin by forming a protective barrier. It is also used as a lubricant and in industrial applications. Its UNII ID is 7EV65EAW6H. Lanolin is a natural product with a long history of use in topical formulations.

C34H68O2

508.9025

508.521

8006-54-0

114471-15-7; 8036-05-3;8038-41-3;8038-43-5;8040-96-8; 8006-54-0;

75778

Light yellow to yellow ointment

38-40 ºC

209 ºC

16.3

0

2

32

36

406

0

O(C(C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H])=O)C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H]

BILPUZXRUDPOOF-UHFFFAOYSA-N

InChI=1S/C34H68O2/c1-3-5-7-9-11-13-15-17-18-19-21-23-25-27-29-31-33-36-34(35)32-30-28-26-24-22-20-16-14-12-10-8-6-4-2/h3-33H2,1-2H3

octadecyl hexadecanoate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~100 mg/mL (~77.32 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (1.93 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (1.93 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (1.93 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)