Chemical Properties
pale yellow viscous liquid
General Description
Pale-yellow or almost colorless transparent viscous liquid with a faint mild odor and nauseating taste. Density 0.95 g / cm3. A mixture of glycerides, chiefly ricinolein (the glyceride of ricinoleic acid) .
Air & Water Reactions
Insoluble in water.
Reactivity Profile
Castor oil can develop heat spontaneously in the air. [Hawley]. Reacts with acids to liberate heat along with alcohols and acids. Heat is also generated by interaction with caustic solutions. Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products. Flammable hydrogen is generated by mixing with alkali metals and hydrides.
Health Hazard
If ingested causes severe diarrhea.
Fire Hazard
Castor oil is combustible.
Hazard
Undergoes spontaneous heating.
Physical properties
The oil is a pale-yellowish or almost colorless, transparent viscid liquid. It is soluble in alcohol,
and is miscible with absolute alcohol, glacial acetic acid, chloroform and ether.
Occurrence
Castor is a perennial found in India and Africa.
Definition
castor oil: A pale-coloured oil extractedfrom the castor-oil plant. Itcontains a mixture of glyceridesof fatty acids, the predominantacid being ricinoleic acid,C17H32(OH)COOH. It is used as adrying oil in paints and varnishesand medically as a laxative.
Indications
Castor oil is a bland oil that is hydrolyzed in the gut
to yield ricinoleic acid, the active purging agent. This
hydrolysis requires bile, a fact that is sometimes overlooked
when castor oil is given as a laxative before radiography
in biliary obstruction.The ricinoleic acid acts
on the ileum and colon to induce an increased fluid secretion
and colonic contraction.
Production Methods
Castor oil is the fixed oil obtained by cold-expression of the seeds of
Ricinus communis Linne (Fam. Euphorbiaceae). No other substances
are added to the oil.
Essential oil composition
The oil is a mixture of triglycerides of which 75 to 90% is ricinoleic acid.* This mixture is hydrolyzed
to release ricinoleic acid, which exerts a cathartic effect. The cake remaining after the extraction of the oil is the castor pomace. The
phytotoxins ricin and ricinine are found in the seed cake and oil. Ricin is a glycoproptein containing neutral A chain and acidic B
chain connected by disulfur bonds.
Pharmaceutical Applications
Castor oil is widely used in cosmetics, food products, and
pharmaceutical formulations. In pharmaceutical formulations,
castor oil is most commonly used in topical creams and ointments
at concentrations of 5–12.5%. However, it is also used in oral tablet
and capsule formulations, ophthalmic emulsions, and as a solvent in
intramuscular injections.
Therapeutically, castor oil has been administered orally for its
laxative action, but such use is now obsolete.
Clinical Use
Castor oil is a bland oil that is hydrolyzed in the gut
to yield ricinoleic acid, the active purging agent. This
hydrolysis requires bile, a fact that is sometimes overlooked
when castor oil is given as a laxative before radiography
in biliary obstruction.
Safety
Castor oil is used in cosmetics and foods and orally, parenterally,
and topically in pharmaceutical formulations. It is generally
regarded as a relatively nontoxic and nonirritant material when
used as an excipient.
Castor oil has been used therapeutically as a laxative and oral
administration of large quantities may cause nausea, vomiting,
colic, and severe purgation. It should not be given when intestinal
obstruction is present.
Although widely used in topical preparations, including
ophthalmic formulations, castor oil has been associated with
some reports of allergic contact dermatitis, mainly to cosmetics
such as lipsticks.
storage
Castor oil is stable and does not turn rancid unless subjected to
excessive heat. On heating at 3008℃ for several hours, castor oil
polymerizes and becomes soluble in mineral oil. When cooled to
08℃, it becomes more viscous.
Castor oil should be stored at a temperature not exceeding 258℃
in well-filled airtight containers protected from light.
Incompatibilities
Castor oil is incompatible with strong oxidizing agents.
Regulatory Status
GRAS listed. Included in the FDA Inactive Ingredients Database
(IM injections; ophthalmic emulsions; oral capsules and tablets;
topical creams, emulsions, ointments, and solutions). Included in
nonparenteral medicines licensed in the UK. Included in the
Canadian List of Acceptable Non-medicinal Ingredients.
