Tetratriacontanol or Cetylstearyl Alcohol, also known as cetearyl alcohol or cetostearyl alcohol, is a mixture of fatty alcohols, primarily cetyl and stearyl alcohol. It is widely used in cosmetics and dermatology as an emollient, emulsifying agent, and stabilizer in a variety of skincare and haircare products.

Composition. Cetylstearyl alcohol is composed of long-chain saturated fatty alcohols, which give it moisturizing properties and the ability to form protective barriers on the skin and hair.

Chemical Industrial Synthesis Process

The production of cetylstearyl alcohol, also known as cetearyl alcohol, an emulsifier and conditioning agent used in cosmetics and personal care products, follows a chemical synthesis process that involves the reduction of fatty acids or the hydrogenation of fatty acid esters. Here is a detailed overview of the process.

• Selection of Raw Materials. Production begins with the selection of fatty acids or their esters as raw materials, typically derived from palm oil or coconut oil, which contain high amounts of stearic acid and palmitic acid.
• Hydrogenation. The fatty acids or their esters undergo hydrogenation, a process that reduces the carbon-carbon double bonds present in the fatty acid chains, converting them into saturated alcohols. This process requires the use of a catalyst, typically nickel-based, and controlled conditions of temperature and pressure.
• Separation and Purification. After hydrogenation, the product mixture is subjected to separation and purification processes to isolate cetylstearyl alcohol from other reaction products and by-products. This may include distillation, crystallization, or other purification techniques.
• Blending. Cetylstearyl alcohol is often a mixture of fatty alcohols, primarily cetyl alcohol (C16) and stearyl alcohol (C18). The proportion of these alcohols can be adjusted based on the specific needs of the final product.
• Quality Control. The final product undergoes quality control checks to verify purity, composition, and physical properties, such as melting point and iodine value. These tests can include analytical methods such as gas chromatography (GC) and spectroscopy.

Form and Color. Cetearyl Alcohol appears as a white powder or almost white waxy substance.

What it is used for and where

Medical

Used by the pharmaceutical industry as an ointment, emulsifying wax, component of creams. It is typically included in corticosteroid creams.

The structure of an oil cream suspended in water or stable aqueous phase (o/w) is characterized by a more or less pronounced mixed crystal bilayer. The addition of co-emulsifiers to achieve a soft formulation often leads to a mixed crystal bilayer network of high viscosity and even phase separation. The purpose of this investigation was to find the optimal amount of co-emulsifier as a texture excipient for the base formulation of an O/W glyceride cream with the co-emulsifiers glyceryl monostearate (Imwitor 900), cetostearyl alcohol (Lanette O), and PEG-20-glycerolostearate (1).

The authors of this study used thermogravimetric analysis, differential scanning calorimetry, ultracentrifugation, and scanning electron microscopy to study the distribution of water in an antiseptic cream prepared with cetostearyl alcohol and cetrimide. In addition to a free water phase, two types of interlamellar fixed water were found, one associated with the liquid crystalline network around the oil droplets and one associated with the liquid crystalline network of the bulk (2).

Cosmetics

Emulsifier. Emulsions are thermodynamically unstable. Emulsifiers have the property to reduce the oil/water or water/oil interfacial tension, improve emulsion stability and also directly influence the stability, sensory properties and surface tension of sunscreens by modulating their filmometric performance. 

Safety. Emulsifiers are an uncommon cause of allergic contact dermatitis. Five cases of allergic contact dermatitis to cetostearyl alcohol are presented. In all five cases, multiple positive reactions to other allergens were present, usually topical corticosteroid creams (3).

The most relevant studies on the subject have been selected with a summary of their contents:

Cetostearyl alcohol studies

Typical commercial product characteristics Cetostearyl alcohol

Appearance	White powder
Boiling Point	515.169ºC at 760 mmHg
Flash Point	132.853ºC
Density	0.842g/cm3
Refraction Index	1.46
PSA	40.46000
LogP	11.70020
Acid value	<0.1 mgKOH/g
Saponification value	<0.5 mgKOH/g
Hydroxyl value	210~220  mgKOH/g
Iodine	<0.5 gI2100g
Alkane	<0.5%
Moisture	<0.15% mass fraction
Carbonyl	<300 ppm
Shelf life	2 years
Chemical Safety

• Molecular Formula: C₃₄H₇₂O₂
• Molecular Weight: 512.9 g/mol
• CAS: 67762-27-0
• UNII 2DMT128M1S
• EC Number: 267-008-6
• DSSTox Substance ID: DTXSID0028323

• IUPAC  hexadecan-1-ol;octadecan-1-ol
• InChl=1S/C18H38O.C16H34O/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19;1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17/h19H,2-18H2,1H3;17H,2-16H2,1H3
• InChl Key      UBHWBODXJBSFLH-UHFFFAOYSA-N
• SMILES   CCCCCCCCCCCCCCCCCCO.CCCCCCCCCCCCCCCCO
• MDL number  
• PubChem Substance ID     
• RXCUI       1307840
• NACRES NA,22 

Synonyms:

• Cetearyl alcohol
• Cetyl/stearyl alcohol
• hexadecan-1-ol;octadecan-1-ol

References___________________________________________________________________

(1) Ballmann C, Mueller BW. Stabilizing effect of cetostearyl alcohol and glyceryl monostearate as co-emulsifiers on hydrocarbon-free O/W glyceride creams. Pharm Dev Technol. 2008;13(5):433-45. doi: 10.1080/10837450802247952.

(2) Rowe RC, Bray D. Water distribution in creams prepared using cetostearyl alcohol and cetrimide. J Pharm Pharmacol. 1987 Aug;39(8):642-3. doi: 10.1111/j.2042-7158.1987.tb03443.x. 

(3) Rademaker M, Wood B, Greig D. Contact dermatitis from cetostearyl alcohol. Australas J Dermatol. 1997 Nov;38(4):220-1. doi: 10.1111/j.1440-0960.1997.tb01705.x.