Castor oil, hydrogenated

• BPHydrogenated Castor Oil
• Ph. Eur.Castor Oil, Hydrogenated
• USP–NFHydrogenated Castor Oil

Castor wax; Castorwax; Cutina HR; glyceryl tri(12-hydroxystearate); Kolliwax HCO; opal wax; ricini oleum hydrogenatum; trihydroxystearin

Mainly glyceryl tri(12-hydroxystearate) · [8001-78-3]

C57H110O9 · 939.5

Lubricant, Semi-solid base, emollient

Typical concentrations: 0.1–2% lubricant · Dosage forms: Solid, Semi-solid

Used as a hydrophobic matrix former and coating material in sustained-release tablets and capsules, as a tablet lubricant, and as a stiffening agent in creams, ointments, sticks and suppository bases. It is also used in cosmetics.

A fine, white to yellowish-white, waxy powder, flakes or pellets with little or no odour.

Melting range

≈ 83–88 °C

Hydroxyl value

145–165

Iodine value

≤ 5

Solubility

practically insoluble in water and light petroleum; slightly soluble in methylene chloride; very slightly soluble in ethanol

Stable. Store in a well-closed container in a cool, dry place.

Incompatible with strong oxidising agents.

Prepared by catalytic hydrogenation of refined castor oil, usually with a nickel catalyst, which saturates the double bond of ricinoleic acid to give 12-hydroxystearic acid esters.

Regarded as non-toxic and non-irritant in oral and topical products at the levels used.

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

Included in the FDA Inactive Ingredient Database (oral capsules and tablets; topical preparations) and in non-parenteral medicines licensed in Europe.

Castor oil; hydrogenated vegetable oil; polyoxyl 40 hydrogenated castor oil.

The hydroxyl groups give it a higher melting point and greater polarity than other hydrogenated vegetable oils; it can be incorporated by melt granulation or hot-melt extrusion as well as by direct blending.