Oleum Amygdalae Expressum (U. S. P.)—Expressed Oil of Almond.
Related entries: Amygdala.—Almond - Oleum Amygdalae Amarae (U. S. P.)—Oil of Bitter Almond
"A fixed oil expressed from the bitter or sweet almond. It should be kept in well-stoppered bottles, -in a cool place"—(U. S. P.).
SYNONYMS: Oleum amygdalae (Br.), Oleum amygdalae dulcis, Oleum amygdalarum, Expressed oil of almond, Sweet oil of almond.
Preparation.—Both bitter and sweet almonds deprived of the adherent brownish dust by means of rubbing or sifting, and freed from inferior pieces, are bruised or ground, put into a bag, and strongly pressed between perfectly smooth and slightly warmed steel plates. The heat should not be greater than 30° C. (86° F.). The margins of the press-cake, if again powdered and expressed, yield an additional quantity of oil. At first the oil is turbid. It is allowed to stand, and the clear oil is then decanted. The yield is from 40 to 55 per cent for sweet almonds; about 30 to 50 per cent for bitter almonds. The highest yields are obtained only by strong hydraulic pressure. If almonds be immersed in hot water, deprived of their cuticular covering, oven-dried and then expressed, a colorless oil is obtained, but it is more liable to become rancid than if prepared as above directed, and to develop a prussic acid odor.
Description and Chemical Composition.—"A clear, pale straw-colored or colorless, oily liquid, almost inodorous, and having a mild, nutty taste. Specific gravity, 0.915 to 0.920 at 15° C. (59° F.). Only slightly soluble in alcohol, soluble in ether and in chloroform in all proportions. It remains clear at -10° C. (14° F.), and does not congeal until cooled to near -20° C. (-4° F.)"—(U. S. P.).
Almond oil is non-drying and when exposed to the atmosphere is liable to become rancid and acrid. Benzin and the fixed oils readily dissolve it in all proportions. The coloring matter, together with a small portion only of the oil, is dissolved by alcohol. According to G. M. Beringer (Amer. Jour. Pharm., 1889, p. 232), 1 part of oil of almond is completely dissolved in 4 parts of boiling absolute alcohol, and in 34 parts of the same solvent at ordinary temperature, while 42 parts of boiling alcohol of the specific gravity 0.820, are required for complete solution. Expressed oil of almond consists principally of the glyceride of oleic acid with appreciable amounts of the glyceride of linoleic acid (see A. Hazura, in Amer. Jour. Pharm., 1889, p. 471).
Tests.—"If 2 Cc. of the oil be vigorously shaken with 1 Cc. of fuming nitric acid and 1 Cc. of water, a whitish, not red or brownish, mixture, should be formed, which, after standing for some hours at about 10° C. (50° F.), should separate into a solid, white mass, and a scarcely colored liquid (distinction from the fixed oils of apricot and peach kernels, and from sesamum, cotton-seed and poppy-seed oils). If 10 Cc. of the oil be mixed with 15 Cc. of a 15 per cent solution of sodium hydrate and 10 Cc. of alcohol, and the mixture allowed to stand at a temperature of 35° to 40° C. (95° to 104° F.), with occasional agitation, until it becomes clear, and then diluted with 100 Cc. of water, the clear solution thus obtained, upon the subsequent addition of an excess of hydrochloric acid, will set free a layer of oleic acid. This, when separated from the aqueous liquid, washed with warm water, and clarified in a water-bath, will remain liquid at 15° C. (59° F.), although sometimes depositing particles of solid matter and becoming turbid. One part of this oleic acid, when mixed with 1 volume of alcohol, should give a clear solution, which, at 15° C. (59° F.) should not deposit any fatty acids, nor become turbid on the further addition of 1 volume of alcohol (distinction from olive, arachis, cottonseed, sesamum, and other fixed oils)"—(U. S. P.).
Action, Medical Uses, and Dosage.—A non-poisonous, bland oil of agreeable taste, which may be given like olive oil, in dose of 1 to 8 drachms in mucilage or egg emulsion for the relief of chronic coughs.