Castor oil

Chemical properties

pale yellow viscous liquid

Chemical properties

Dehydrated castor oil is a castor oil from which approximately 5% of the chemically combined water has been removed. Therefore it has drying properties similar to those of Tung oil. Dehydration is carried out by heating the oil in the presence of catalysts such as sulphuric acid, phosphoric acid, clays and metal oxides. Dehydrated castor oil is a yellow oily liquid with characteristic odour.
Standard specifications
commercial grade pale grade special grade
refractive index (20°C) 1,482 - 1,483 1,482 - 1,483 1,482 - 1,483
specific gravity (15°C) 0,982 - 0,933 0,982 - 0,933 0,982 - 0,933
viscosity (25°C) Poise 1,6 - 2,8 1,6 - 2,8 1,6 - 2,8
viscosity Gardner scale G – I G – I G – I
colour max. 8 max. 6 max. 5
acid value mg KOH/g max.6 max. 4
iodine value (Wijs) g I2/100g min. 130 min. 130 min. 130
hydroxyl value mg KOH/g max. 25 max. 20

Chemical properties

Castor oil is a clear, almost colorless or pale yellow-colored viscous oil. It has a slight odor and a taste that is initially bland but afterwards slightly acrid.

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.

The Uses of Castor oil

Castor Oil, derived from the seeds of the Ricinus communis plant through a cold-pressing process, is a versatile substance with various applications:

1. In Food Production: It acts as a release and antisticking agent in the manufacturing of hard candies, with a concentration limit of 500 parts per million (ppm) to ensure safety and quality.

2. In Pharmaceutical Formulations: Castor Oil is utilized in vitamin and mineral tablets and as a component of protective coatings, highlighting its role in the pharmaceutical industry.

3. Cosmetic and Skincare Industry: Recognized for its emollient properties, castor oil penetrates the skin easily, imparting softness and suppleness. It also functions as a binding agent in cosmetic formulations, helping to integrate different ingredients.

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.

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.

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.

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.

Hazard

Undergoes spontaneous heating.

Health Hazard

If ingested causes severe diarrhea.

Fire Hazard

Castor oil is combustible.

Pharmaceutical Applications

Castor oil is a versatile substance with applications in cosmetics, food products, and pharmaceutical formulations:

1. In Pharmaceutical Formulations: It is commonly used in topical creams and ointments at concentrations ranging from 5% to 12.5%. Additionally, castor oil finds use in oral tablet and capsule formulations, ophthalmic emulsions, and serves as a solvent for intramuscular injections.

2. Therapeutic Use: Historically, castor oil was administered orally for its laxative effects. However, this method of use is now considered obsolete.

3. Cosmetics and Food Products: Beyond its pharmaceutical applications, castor oil is also widely utilized in the cosmetics industry and food products, although the specific uses in these industries are not detailed in the provided content.

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 Profile

An allergen. A human skin and eye irritant. Combustible when exposed to heat. Spontaneous heating may occur. To fight fire, use CO2, dry chemical, fog, mist. See also CASTOR BEAN.

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.