Functional Category
Extended release agent; stiffening agent; tablet and capsule lubricant
Applications in Pharmaceutical Formulation
Hydrogenated castor oil is a hard wax with a high melting point used in oral and topical pharmaceutical formulations; see Table I. In topical formulations, hydrogenated castor oil is used to provide stiffness to creams and emulsions.(1) In oral formulations, hydrogenated castor oil is used to prepare sustained-release tablet and capsule preparations;(2,3) the hydrogenated castor oil may be used as a coat or to form a solid matrix. Hydrogenated castor oil is additionally used to lubricate the die walls of tablet presses;(4,5) and is similarly used as a lubricant in food processing. Hydrogenated castor oil is also used in cosmetic
Description
Hydrogenated castor oil occurs as a fine, almost white or pale yellow powder or flakes. The PhEur 6.0 describes hydrogenated castor oil as the oil obtained by hydrogenation of virgin castor oil. It consists mainly of the triglyceride of 12-hydroxystearic acid
Stability and Storage Conditions
Hydrogenated castor oil is stable at temperatures up to 1508C. Clear, stable, chloroform solutions containing up to 15% w/v of hydrogenated castor oil may be produced. Hydrogenated castor oil may also be dissolved at temperatures greater than 908C in polar solvents and mixtures of aromatic and polar solvents, although the hydrogenated castor oil precipitates out on cooling below 908C. Hydrogenated castor oil should be stored in a well-closed container in a cool, dry place
Incompatibilities
Hydrogenated castor oil is compatible with most natural vegetable and animal waxes
Safety
Hydrogenated castor oil is used in oral and topical pharmaceutical formulations and is generally regarded as an essentially nontoxic and nonirritant material. Acute oral toxicity studies in animals have shown that hydrogenated castor oil is a relatively nontoxic material. Irritation tests with rabbits show that hydrogenated castor oil causes mild, transient irritation to the eye. LD50 (rat, oral): >10 g/kg