Stearyl alcohol

• BPStearyl Alcohol
• JPStearyl Alcohol
• Ph. Eur.Stearyl Alcohol
• USP–NFStearyl Alcohol

alcohol stearylicus; Crodacol S95; Lanette 18; 1-octadecanol; octadecyl alcohol

Octadecan-1-ol · [112-92-5]

UNII 2KR89I4H1Y · PubChem CID 8221

C18H38O · 270.49

Semi-solid base, emollient

Typical concentrations: — · Dosage forms: Semi-solid

Used in creams and ointments as a stiffening agent and co-emulsifier: it increases viscosity, stabilises emulsions and increases the water-holding capacity of ointment bases. Hydrophilic Ointment USP, for example, contains 25% w/w. It has also been used as a matrix-forming agent in sustained-release tablets and in cosmetics.

Hard, white, waxy pieces, flakes or granules with a faint characteristic odour and a bland taste. It is a mixture of solid aliphatic alcohols consisting mainly of stearyl alcohol (Ph. Eur.: at least 95%).

Melting point

about 55–60 °C

Hydroxyl value

≈ 195–220

Iodine value

not more than 2

Solubility

soluble in chloroform, ethanol (95%) and ether; practically insoluble in water

Stable to acids and alkalis and does not usually become rancid. Store in a well-closed container in a cool, dry place.

Incompatible with strong oxidising agents.

Made by catalytic hydrogenation (reduction) of stearic acid or its esters derived from vegetable or animal fats, followed by purification; it can also be produced synthetically from petrochemical feedstocks.

Generally regarded as non-toxic and non-irritant in topical use. Occasional hypersensitivity reactions, mainly contact dermatitis and urticaria, have been attributed to it, though these are less frequent than with cetyl or cetostearyl alcohol.

Observe normal precautions for the quantity handled. Eye protection and gloves are recommended. It is combustible.

Permitted in the USA as a synthetic fatty alcohol food additive. Included in the FDA Inactive Ingredient Database (topical and vaginal preparations, and some oral products) and in non-parenteral medicines licensed in Europe.

Anionic emulsifying wax; cetostearyl alcohol; cetyl alcohol; nonionic emulsifying wax.

Stearyl alcohol gives firmer creams than cetyl alcohol of similar concentration. In combination with a hydrophilic surfactant it forms a gel network in the continuous phase of o/w creams, which accounts for much of their consistency.