Oil of savin is obtained by distillation from the fresh tops of savin, Juniperus Sabina, Linn. (N.O. Coniferae), indigenous to the mountains of Southern Europe and frequently cultivated in Britain. It is official in the U.S.P. Oil of savin occurs as a colourless or yellowish liquid, having a peculiar, unpleasant, narcotic odour, and a bitter, pungent, camphoraceous taste. Specific gravity, 0.910 to 0.930 0.903 to 0.923 at 25°). Rotation, +40° to +60°. Saponification value, 115 to 125. Not more than 25 per cent. should distil below 200°. French turpentine, one of the principal adulterants, lowers the specific gravity, reduces or inverts the angle of rotation, lowers the saponification value, and diminishes the solubility in alcohol. French savin oil, derived from Juniperus phoenicea, contains over 75 per cent. of pinene and only about 10 per cent. of sabinyl acetate. It has a lower specific gravity (about 0.890) and a lower optical rotation (+4° to +5°) than true savin oil.
Soluble in half its volume or more of alcohol; in 80 per cent. alcohol (1 in 15 to 20), but not always forming a perfectly clear solution.
Constituents.—The chief constituent of the oil is sabinol, C10H15OH, an alcohol, occurring partly in the free state and partly, combined with acetic acid as ester. The alcohol, of which the oil contains about 10 per cent., is a colourless liquid with a faint odour like that of thujone, boiling at 208° to 209°. The ester, sabinyl acetate, C10H15OCOCH3, present to the extent of 36 to 48 per cent., has an odour like that of savin, and boils at 222° to 224°. Sabinol, oxidised with potassium permanganate, yields quantitatively tanacetogen dicarbonic acid (C9H14O4), melting at 140°. The sesquiterpene cadinene, C15H24, is present, and also a considerable proportion of terpenes, apparently consisting for the most part of pinene (C10H16).
Action and Uses.—Oil of savin is a powerful irritant, both externally and internally. It is employed in amenorrhoea with other emmenagogues, but in addition to pelvic congestion it may cause haematuria and violent gastro-intestinal irritation, and its use, therefore, requires caution. It is usually administered in pills, the oil being massed with liquorice powder and a little soap. In cases of poisoning by oil of savin, an emetic should be administered and castor oil given, with morphine hypodermically.
Dose.—1/2 to 2 1/2 decimils (0.05 to 0.25 milliliters) (1 to 4 minims).
The British Pharmaceutical Codex, 1911, was published by direction of the Council of the Pharmaceutical Society of Great Britain.