Oleum Lavandulae, B.P. Oil of Lavender.

Oil of lavender (Oleum Lavandulae Florum, U.S.P.; Oil of Lavender Flowers) is obtained by distillation from the flowers of Lavandula vera, DC. (N.O. Labiatae), a plant cultivated in England, France, and other countries. It occurs as a pale yellow, yellowish-green, or nearly colourless liquid, having the fragrant odour of the flowers, and a pungent, slightly bitter taste. Specific gravity, 0.882 to 0.900 (0.880 to 0.895 at 25°). Rotation -5° to -10°. The usual adulterants of oil of lavender are the oils of spike and turpentine. Neither contains appreciable quantities of esters, so that in the case of suspected samples the ester determination supplies useful information on this point. Oil of spike (L. Spica, Cav.. is slightly dextrorotatory, and therefore diminishes the rotatory power. American turpentine has the same effect. French turpentine, on the other hand, increases the laevorotation. Oil of turpentine further decreases the specific gravity and the solubility in 70 per cent. alcohol. Oil of spike does not influence the solubility but decreases the ester content. A large cineol content in the French oil indicates adulteration with oil of spike. Ethyl succinate has also been used as an adulterant.

Soluble in all proportions of alcohol, absolute alcohol, and in three volumes of alcohol (70 per cent.), forming a clear solution.

Constituents.—The chief constituents of the oil are the alcohol linalool, C₁₀H₁₈O, and its acetic ester, linalyl acetate, C12H20O₂, of which there is 7 to 11 per cent. in the English oil, and 25 to 45 per cent. in the French oil. Other constituents are pinene, C₁₀H16; limonene, C₁₀H16; geraniol, C₁₀H₁₈O, and a sesquiterpene, C₁₅H24. Cineol, C₁₀H₁₈O, is found in some quantity in English oil, but only in traces in French oil. English oil, which undoubtedly has the finest odour, contains but little linalyl acetate, but the fineness and value of French oils appear to stand in direct ratio to the amount of linalyl acetate present. The English oil is sometimes described as being easily distinguishable from the French by its cineol-like odour, and this is readily understood when it is remembered that the former contains an appreciable quantity of cineol.

Action and Uses.—Oil of lavender has the aromatic and carminative properties of the volatile oils generally. It is not much employed internally other than as a flavouring agent; the oil or the spirit of lavender may be administered on sugar in flatulence and colic; red lavender lozenges are employed as a mild stimulant and for their pleasant taste; compound tincture of lavender is a useful colouring and flavouring agent for mixtures. Oil of lavender is largely employed in perfumery, and is occasionally useful in pharmacy to cover disagreeable odours in ointments and other compounds. The oil is reputed to be objectionable to midges and mosquitoes, and is therefore smeared on exposed parts of the skin to prevent insect bites.

Dose.—¼ to 2 decimils (0.025 to 0.2 milliliters) (½ to 3 minims).

PREPARATIONS.

Compound Menthol Wool - Red Lotion

Spiritus Lavandulae, B.P.—SPIRIT OF LAVENDER.

Oil of lavender, 10; alcohol, sufficient to produce 100. Spirit of lavender is used as a flavouring agent and perfume; also to dab on the skin to prevent insect bites. Dose.—3 to 12 decimils (0.3 to 1.2 milliliters) (5 to 20 minims).

Spiritus Lavandulae, U.S.P.—SPIRIT OF LAVENDER.

Oil of lavender flowers, 5; alcohol (95 per cent.), 95.

Tinctura Lavandulae Composita, B.P.—COMPOUND TINCTURE OF LAVENDER.

Oil of lavender, 0.47; oil of rosemary, 0.05; cinnamon bark, bruised, 0.85; nutmeg, bruised, 0.85; red sanders wood, 1.7; alcohol, sufficient to produce 100. Macerate the drugs in the alcohol for seven days, and complete the maceration process, finally dissolving the oils in the strained liquid. Compound tincture of lavender is used as a flavouring and colouring agent. Dose.—2 to 4 mils (A to 1 fluid drachm).

Tinctura Lavandulae Composita, U.S.P.—COMPOUND TINCTURE OF LAVENDER, U. S. P.

Oil of lavender flowers, 0.8; oil of rosemary, 0.2; Saigon cinnamon, 2. cloves, 0.5; nutmeg, 1; red sanders wood, 1; alcohol (72 per cent.), sufficient to produce 100. Average dose.—2 mils (30 minims).

The British Pharmaceutical Codex, 1911, was published by direction of the Council of the Pharmaceutical Society of Great Britain.