Oleum Cassiae. U. S. (Br.) Oil of Cinnamon.

Botanical name: 

Ol. Cass. [Oleum Cinnamomi U. S. VIII, Cassia Oil]

Related entry: Cinnamon

"A volatile oil distilled from Cinnamomum Cassia (Nees) Blume (Fam. Lauraceae), rectified by steam distillation and yielding not less than 80 per cent., by volume, of cinnamic aldehyde [C9H8O = 132.06]. Preserve it in well-stoppered, amber-colored bottles, in a cool place, protected from light." U. S. "Oil of Cinnamon is the oil distilled from Cinnamon Bark." Br.

Oleum Cinnamomi, Br.; Oleum Cinnamomi Cassiae; Oil of Chinese Cinnamon, Essence de Cannelle de Chine, Huile volatile de Cannelle, Fr.; Oleum Cinnamomi, P. G.; Zimmtöl, Zimmtkassienöl, G.; Essenza di Cannella, It.

There are two oils of cinnamon in commerce, one procured from the Ceylon cinnamon, the other from the Chinese cinnamon, and often distinguished by the name of oil of cassia. There is no essential difference in the two oils, and that of the Chinese cinnamon, as much the cheaper and more abundant of the two, will probably continue to be generally employed, notwithstanding that the Ceylon product has the finer flavor. The U. S. P. IX and the German Pharmacopoeia recognize as oil of cinnamon only that obtained from cassia. The British Pharmacopoeia and French Codex make Oil of Ceylon Cinnamon official.

Preparation.—Oil of cinnamon of Ceylon is distilled from inferior kinds of cinnamon, of insufficient value to pay the export duty. The following account of the method of extraction is given by Marshall. The bark, having been coarsely powdered, is macerated for two days in sea water, and then submitted to distillation. A light and a heavy oil come over with the water, the former of which separates in a few hours and floats upon the surface, the latter falls to the bottom of the receiver, and continues to be deposited for ten or twelve days. In future distillations, the saturated cinnamon water is employed with sea water to macerate the cinnamon. Eighty pounds of the freshly prepared bark yield about 2.5 ounces of the lighter oil, and 5.5 of the heavier. From the same quantity kept for several years in store, about half an ounce less of each oil is obtained. The two kinds are 'probably united in the oil of commerce. The oil is also distilled in Ceylon from the leaves, but the product is said to be too small to yield a fair profit. (C. D., 1888.) The exportation of cinnamon chips from Ceylon has assumed large proportions, amounting in 1904 to 2,135,220 pounds. (Schim. Rep., May,

Properties.—Oil of Ceylon cinnamon is of a light-yellow color, becoming deeper by age, and ultimately red. Pereira stated that the London druggists redistilled the red oil, and thus obtained two pale-yellow oils, one lighter and the other heavier than water, with a loss of about 10 per cent. in the process. The oil has the flavor of cinnamon, and when undiluted is excessively hot and pungent. It is said sometimes to have a peppery taste, ascribable to an admixture of the leaves with the bark in the preparation of the oil. Oil of Ceylon cinnamon has "a slightly acid reaction. Sp. gr. about 1.040. It is readily soluble in alcohol. When cooled to -10° C. (14° F.), it remains clear, but at a lower temperature a solid portion separates from it." U. S. 1880. To ascertain whether, in the distillation of oil of cinnamon from the bark, some of the oil is oxidized to cinnamic aldehyde in part and thus the yield lowered, H. A. Phillips (Tr. Br. Ph. Conf., 1914, 371) made a thorough investigation of the subject and concludes that under the ordinary conditions of steam distillation, cinnamic aldehyde is not appreciably oxidized. The British Pharmacopoeia 1914 recognizes oil of Ceylon cinnamon only, and gives the following description and tests: " Yellow when freshly distilled, gradually becoming reddish. Odor and taste those of Cinnamon Bark. Specific gravity 1.000 to 1.030; optical rotation -0.5° to -1°; refractive index at 25° C. (77° F.) 1.565 to 1.580. Soluble in from 3 to 4 parts of alcohol (70 per cent.). 1 drop dissolved in 5 millilitres of alcohol (90 per cent.) assumes a pale green, but not a blue or brown coloration, on the addition of 1 drop of I. Sol. of ferric chloride (absence of cinnamon leaf oil and cassia oil). Contains from 55 to 65 per cent. of cinnamic aldehyde as determined by the following test: To 10 millilitres of the Oil add 70 millilitres of an aqueous solution (1 in 5) of sodium sulphite and sufficient solution of phenolphthalein to give a well marked pink coloration. Heat the mixture on a water-bath, shake well, and neutralise with acetic acid diluted with twice its volume of water; repeat the heating and neutralisation until no further pin-k coloration is developed, the time occupied being from thirty to forty-five minutes. The oily layer which separates on standing, cooled to 35.5° C. (60° F.), measures not more than 4.5 or less than 3.5 millilitres (presence of 55 to 65 per cent. of cinnamic aldehyde)." Br.

Chinese oil of cinnamon is imported from Canton and Singapore. It is pale yellow, becoming red with age. Its flavor is similar to that of the Ceylon oil, though inferior, and it commands a much lower price. It is officially described as follows: "Oil of Cinnamon (Cassia) is a yellowish or brownish liquid, becoming darker and thicker by age and exposure to the air and having the characteristic odor and taste of cinnamon. Specific gravity: 1.045 to 1.063 at 25° C. (77° F.). The optical rotation varies from +1° to -1° in a 100 mm. tube at 25° C. (77° F.) It does not respond to the Test for heavy metals in volatile oils. Shake 2 mils of the Oil in a test tube with from 5 to 10 mils of purified petroleum benzin, and decant the latter; this liquid is colorless and does not assume a green color upon shaking it with an equal volume of (1 in 1000) copper acetate solution (rosin).

The cinnamon leaf oil, as formerly imported into Great Britain, was of two kinds, one containing a considerable quantity of a fatty fixed oil, perhaps cinnamon-suet from the fruit, the other a pure volatile oil. The oil was said to be obtained by distilling the leaves after maceration in sea water. It resembled the oil of clove and pimento in sensible properties, having a brownish color, a penetrating, fragrant odor, and a very pungent taste. According to Stenhouse, it was of the sp. gr. 1.053, had an acid reaction, and consisted of eugenol, a neutral substance with the formula ..., and a minute proportion of benzoic acid. (P. J., xiv, 319.) Schimmel & Co. found it to have a sp. gr. 1.056 to 1.060, and contained 87 per cent. of eugenol, and about 0.1 per cent. of cinnamic aldehyde.

When exposed to the air, the oil absorbs oxygen, and is slowly converted into cinnamic acid, two distinct resins, and water. Of the two resins, one is soluble both in hot and in cold alcohol; the other readily in the former, but sparingly in the latter. Cinnamic acid, C9H8O2, is colorless, crystalline, sourish, volatilizable, slightly soluble in water, readily dissolved by alcohol, and convertible by nitric acid with heat into benzoic acid. It is sometimes seen in crystals in oil of cinnamon which has been long kept. Like benzoic acid, it is said when swallowed to cause the elimination of hippuric acid by the urine. (J. P. C., 3e ser., iii, 64.) It may be obtained by distilling the balsam of Tolu. Oil of cinnamon is almost wholly converted by nitric acid, slowly added, into a crystalline mass, producing a compound of the oil and the acid. These several facts are explained when it is found that oil of cinnamon contains from 75 to 90 per cent. of cinnamic aldehyde, C9H8O, which by moderate oxidation yields the corresponding cinnamic acid, C9H8O2, but by more energetic oxidation yields benzoic acid, C7H6O2. The oil has been produced artificially by Strecker from styrone, a derivative from styrax (see Styrax), and more recently from benzaldehyde and acetaldehyde, a mixture of which is saturated with hydrochloric acid gas, when a condensation takes place, as follows:


Ordinary sodium hydroxide will also bring about the reaction between the two aldehydes, and is to be preferred to hydrochloric acid for this purpose.

Oil of cinnamon is said to be frequently adulterated with oil of cloves, which, according to Ulex, cannot be detected by the odor or taste. Thus sophisticated, it is stated, on the same authority, to evolve a very acrid vapor when a drop is heated on a watch glass, to swell up sad evolve red vapors if treated with fuming nitric acid, to remain liquid with concentrated potassium hydroxide, and to assume an indigo-blue color when ferrous chloride is added to its alcoholic solution, none of which reactions occur with pure oil.

Uses.—Although a very powerful germicide the oil of cinnamon, because of its irritant properties, is rarely used in medicine as an anti-bacterial. It has the cordial and carminative properties of cinnamon, without its astringency, and is much employed as an adjuvant to other medicines, the taste of which it corrects or conceals, while it conciliates the stomach. As a powerful local stimulant, it is sometimes prescribed in gastrodynia, flatulent colic, and gastric debility. Mitscherlich found six drachms to kill a moderate-sized dog in five hours, and two drachms one in forty hours. Inflammation and corrosion of the gastro-intestinal mucous membrane were observed after death.

Dose. one to three minims (0.06-0.2 mil).

Off. Prep.—Aqua Cinnamomi, U. S.; Spiritus Cinnamomi, U. S., Br.; Infusum Digitalis (from Water), U. S.; Mistura Cretae (from Water), U. S.; Elixir Cardamomi Compositum (from Compound Spirit), N. F.; Elixir Glycyrrhizae Aromaticum, N. F.; Elixir Vanillini Compositum (from Compound Spirit), N. F.; Mistura Oleo-Balsamica, N. F.; Nebula Aromatica, N. F.; Nebula Mentholis Composita, N. F.; Spiritus Cardamomi Compositus, N. F.; Spiritus Vanillini Compositus, N. F.

The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.