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Oil of Theobroma - Cocoa Butter
Martindale�s 24th - United States Dispensatory 1926
Compiled and edited by Ivor Hughes.

1. Martindale�s 24th
Theobroma Oil (B.P.) 0l. Theobrom. Cacao Butter; Cocoa Butter;

Oleum Cacao; Butyrum Cacao; Beurrede Cacao; Manteca de cacao.Foreign Pharmacopeias: In all pharmacopoeias examined.

A solid fat expressed from the roasted seeds of Theobroma cacao. A pale yellow solid, becoming white on keeping, with a slight odour of cocoa and a bland taste. It is sometimes deodorised. M.p. 31C to 34C (below body temperature). Slightly soluble in alcohol; soluble in benzene, chloroform. ether, light petroleum. and boiling dehydrated alcohol.

Uses. Theobroma oil is usually employed as the basis for suppositories and pessaries. When the suppositories are prepared by melting and moulding care should be taken not to overheat this basis since overheating will cause a lowering of the solidifying point and subsequent difficulty in setting. Certain medicaments, such as phenol, chloral hydrate, and resorcinol, cause an appreciable lowering of the melting-point of theobroma oil when warmed with it. 

In preparing suppositories containing these, the melting-point may be brought back to normal by incorporating a little white beeswax. This addition may be avoided. except in the case of suppositories containing volatile oils. by using the minimum amount of heat.

In hot climates it is customary to incorporate 5 to 15% of white beeswax according to the prevailing temperature. Different samples of both theobroma oil and white beeswax may each have different melting-points, so that variation will occur in mixtures. Using theobroma oil with m.p. 34C and white beeswax with m.p. 61C, the melting-points of mixtures are as follows:

White Beeswax (%) 2�        10     15       20
Melting-point: 32.5C.     39.5C    46C       50C

When intended for use in hot climates, or when containing volatile ingredients, suppositories should be wrapped separately in tinfoil. Urethral bougies and aural bougies may also be prepared with a basis of theobroma oil. Theobroma oil is sometimes an ingredient of emollient ointments and it is also used as a lubricant in massage.


2. United States Dispensatory 1926
OLEUM THEOBROMATIS. U. S., Br.
OIL OF THEOBROMA Ol. Theobrom. [Cacao Butter]

The fat obtained from the roasted seeds of Theobroma Cacao Linne (Fam. Sterculiaceae) U.S. Oil of Theobroma is a solid fat expressed from the seeds of Theobroma Cacao,

Oleum Theobroma U.S.1880: Butter of Cacao: Cocoa butter (improperly) Beurre de Cacao. Fr. Cod.: Oleum concretum e semine Theobromae Cacao, Fr.:Oleum Cacao, P. G.; Kakaobutter, G.: Manteca de coco, Aceite de coco, Sp

For description of this tree see under Cacao Preparata.

Oil of theobroma is extracted either by expression, decoction, or the action of a solvent. Soubeiran recommends that the seeds, previously ground, be mixed with one-tenth of their weight of water and then pressed between hot plates of tinned iron. It is advisable that the heat should not exceed that of boiling water, and even a lower heat will answer. When the method of decoction is used, the cacao should be slightly roasted before boiling. As a solvent, carbon disulphide has been found to answer well, as recommended in the preparation of the expressed oil of nutmeg. (See Oleum Myristicae) Upon the whole, the method of expression is perhaps preferable. The presence of water in the ground seeds is said greatly to facilitate the process. The commercial supply is largely a by-product in the manufacture of cocoa. It occurs usually in the shape of oblong cakes, weighing about half a pound each.

Description and Physical Properties. A yellowish-white solid, having a faint, agreeable odor, and a bland, chocolate-like taste. It is usually brittle at temperatures below 25 C. Oil of Theobroma is slightly soluble in alcohol soluble in boiling dehydrated alcohol; freely soluble in ether, chloroform, petroleum benzin, and in benzene. Specific gravity: about 0.973 at 25C. It melts between 30 and 35 C. Refractive index : 1.4537 to 1.4578 at 40 C

Dissolve 1 Gm. of Oil of Theobroma in 3 00. of ether in a test tube at a temperature of 17 C and immerse the tube in water having the temperature of melting ice: the liquid does not become turbid or deposit white flakes in less than three minutes. After congealing, raise the temperature to 15 C. a clear liquid is gradually formed ( wax, stearin, or tallow) Saponification value: not less than 188 and not more than 195. Iodine value: not less than 33 and not more than 38. U.S.

A yellowish-white solid, breaking with a smooth fracture. Odor resembling that of cocoa; taste bland, agreeable. Somewhat brittle at ordinary temperatures, but softening at 25C.Specific gravity 0.990 to 0.998; melting point 30 to 33 C. Saponification value 188 to 195. Iodine value 35.5 to 37.5; acid value not more than 2.0. Refractive index at 40 C. 1.4565 to 1.4575. In ascertaining the melting point and specific gravity, seventy-two hours should be allowed to elapse between the time of melting and the time of determining the constants. When 1 gramme is dissolved at 17 C. in 3 millilitres of ether in a test-tube, and the tube placed in water at 00 C., the solution neither becomes turbid nor deposits a granular or flaky mass in less than three minutes; and if, after congealing, it is exposed to a temperature of 15.5 C., a clear solution is gradually formed (absence of certain other fats).

Br. Cacao butter consists chiefly of the glycerides of stearic, palmitic, and lauric acids, with small quantities of the glycerides of arachidic, linoleic, formic, acetic, and butyric acids. The percentage of stearic acid obtainable is from 39.9 to 40.6. Kingzett believes it to contain in addition a peculiar acid which he calls theobromic, and to which he gives the formula C64H128O2, but his results have not been confirmed by subsequent investigators. From its large proportion of stearin, it is one of the best fats for the preparation of stearic acid. It is said to be frequently adulterated with animal fats, which are excluded by the official tests.

Uses. Butter of cacao is used as an ingredient in cosmetic ointments, and in pharmacy for coating pills and preparing suppositories. For the last purpose it is well adapted by its blandness, and the fact that although liquefying at a temperature below that of the body, it is of firm consistence at 20 C. It is also valuable for the reason that easily decomposable substances like silver nitrate, potassium permanganate, etc., may be incorporated in it without material change and it is therefore valuable as an excipient. It has the emollient properties of the fats and is used to soften and protect chapped hands or lips.

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