Stearic Acid

(USAN, rINNM)
Stearic Acid Chemical formula

Chemical information

Acide stéarique; Acido Esteárico; Acidum stearicum; Esteárico, ácido; Kwas stearowy; Kwas stearynowy; Kyselina stearová; Octadecanoic Acid; Steariinihappo; Stearino ru _ gštis; Stearinsäure; Stearinsyra; Sztearinsav.
CAS — 57-11-4 (stearic acid); 57-10-3 (palmitic acid).

Pharmacopoeias.

In Chin., Eur., and Jpn. Also in USNF. USNF also includes a purified form.

Ph. Eur. 6.2

(Stearic Acid). It is obtained from fat or oils from a vegetable or animal source and is a mixture consisting mainly of stearic acid (C 18 H 36 O 2 = 284.5) and palmitic acid (C 16 H 32 O 2 = 256.4). Stearic Acid 50 contains 40 to 60% stearic acid, the sum of the contents of stearic and palmitic acids being a minimum 90%. Stearic Acid 70 contains 60 to 80% stearic acid, the sum of the contents of stearic and palmitic acids being a minimum 90%. Stearic Acid 95 contains a minimum of 90% stearic acid, the sum of the contents of stearic and palmitic acids being a minimum 96%. White or almost white, waxy, flaky crystals, white or almost white, hard masses, or a white or yellowishwhite powder. Practically insoluble in water; soluble in alcohol and in petroleum spirit (50° to 70°).

USNF 26 (Stearic Acid). A mixture of stearic acid and palmitic acid, the content of stearic acid being not less than 40%, and the sum of the two not less than 90%. Congealing point not lower than 54°. Hard, white or faintly yellowish, somewhat glossy and crystalline solid, or white or yellowish-white powder, with a slight odour, suggesting tallow. Practically insoluble in water; soluble 1 in 20 of alcohol, 1 in 2 of chloroform, and 1 in 3 of ether.

USNF 26 (Purified Stearic Acid). It contains not less than 90% stearic acid and not less than 96% of stearic and palmitic acids. Congealing point 66° to 69°.

Profile

Stearic acid is used as a lubricant in making tablets and capsules. It is also used as an emulsifying and solubilising agent. Various stearates are also used as pharmaceutical aids.
Published May 08, 2019.