Oleum Terebinthinae, B.P. Oil of Turpentine.

Related entries: Resin - Canada turpentine - Oil of Pine - Frankincense - Tar - Oil of Tar - Hemlock spruce bark - Burgundy Pitch - Larch bark

Oil of turpentine, Turpentine or Spirit of Turpentine, is obtained by steam distillation from turpentine, an oleoresin obtained from Pinus sylvestris, Linn. (N.O. Coniferae), and other species of Pinus growing in America, France, Russia, and elsewhere. It is also official in the U. S. P. The varieties of turpentine oil usually found in commerce are the American and French. Most of the oil, however, is imported from the United States. It occurs as a colourless, limpid liquid, having a strong peculiar odour, and a pungent, somewhat bitter taste, both becoming stronger and less pleasant by age and exposure to air. The odour of the French oil is finer and milder than that of the American, which is decidedly terebinthinate. The sharp odour is said to be due to an aldehyde formed by exposure of the oil to the air. Unlike most oils the solubility of the oil increases with age, owing to formation of more easily soluble oxidation products. The solubility as a test, therefore, is of no great value. It dissolves resins, fixed oils, beeswax, iodine, sulphur, and phosphorus. Specific gravity, 0.855 to 0.880 (0.860 to 0.870 at 25°). Rotation of the American variety, which is almost invariably dextrorotatory, +1° to +15°; occasionally, however, it may be slightly laevorotatory, since the oil contains both dextro- and laevorotatory terpenes, the latter sometimes being in excess. The French oil is always strongly laevorotatory, -18° to -40°. The reaction of the oil is generally slightly acid. It is volatile at ordinary temperatures, and boils at about 155°, at least 88 per cent. distilling below 165°. On exposure to the air it undergoes rapid change, especially in the presence of moisture. It then becomes viscid and yellow, the specific gravity increases, the boiling-point rises, solubility in alcohol increases, and the oil, originally neutral, becomes acid and resinifies. These changes are all referable to slow oxidation. The usual adulterants are petroleum (illuminating) and resin oils. The former may be recognised by its lowering the specific gravity, and also by the flashing-point, which for pure turpentine oil lies at 33° to 34°. The resin oil, a product of the destructive distillation of resin, may be detected by the fatty stain which the adulterated oil leaves when evaporated from paper. Other adulterants, such as the volatile portions of shale oil and coal tar, have been used. Oil of turpentine should leave only a very slight residue when evaporated on the water-bath. On being treated with sulphuric acid it yields terebene, a mixture of dipentene, terpinene, and other optically inactive terpenes. It should evaporate entirely, leaving no permanent stain, when exposed to the air on clean white filtering paper. If 5 mils of the oil be placed in a small beaker, and 20 mils of sulphuric acid be gradually added, with agitation, while the beaker is cooled by immersion in cold water, and the contents, after cooling and renewed agitation, be transferred to a burette graduated to tenths of a mil, the clear layer which forms after the dark mass has settled should not measure more than 0.35 mil (absence of petroleum benzin, kerosene, or similar hydrocarbons). Oil of turpentine is rectified for medicinal purposes, and is also purified by means of lime water or solution of potassium hydroxide, any free acid being thus neutralised and removed; further, the resinified portion of the oil may be removed by shaking with alcohol and water alternately. Oxidation products with an acid reaction reform, however, on further exposure. Oleum Terebinthinae Rectificatum, U.S.P., is prepared by shaking oil of turpentine with an equal volume of solution of sodium hydroxide, then recovering about three-fourths of the oil by distillation, separating the clear oil from the water, and filtering. Specific gravity, 0.860 to 0.865 at 25°. Average dose, 1 mil (15 minims).

Soluble in alcohol (1 in 6.25); in all proportions of absolute alcohol, chloroform, ether, carbon bisulphide, or glacial acetic acid (99.5 per cent.).

Constituents.—The chief constituents of the oil are hydrocarbons, principally the two isomeric bodies d- and l-pinene, Other constituents are resin acids, camphene, and fenchene, while dipentene—the optically inactive form of limonene—and polymeric terpenes may occur as the result of the action on pinene of the acids present. Traces of oxidation products, such as formic, acetic, and camphoric acids as well as camphoric aldehyde, C₁₀H₁₆O₃, are also present, the last named giving the peculiar odour to rancid turpentine oil. The American oil consists chiefly of d-pinene, the French oil of l-pinene. In all other respects the composition of the two varieties is similar. There is no ozone present. The action of direct sunlight in presence of moisture and air or oxygen causes the formation of pinol hydrate, C₁₀H₁₈O₂, while continuous action of air in the presence of water develops a large quantity of oxygenated products, including hydrogen peroxide and camphoric acid, this reaction forming the basis of the "Sanitas" series of disinfectants.

Action and Uses.—The action of oil of turpentine is representative of that of a large number of volatile oils. They are antiseptics, used internally or externally, and in sufficient concentration are rapidly germicidal to all forms of bacteria. Applied to the skin they produce irritation and rubefaction, the redness being due to dilatation of the superficial vessels. Inhaled, they arrest profuse secretion, and relieve congestion of the bronchioles, but the degree of concentration obtainable in this manner is insufficient for their antiseptic action to be exerted to any great extent. Taken internally, the volatile oils excite a reflex flow of saliva, and cause a sensation of warmth in the mouth and stomach. They stimulate the stomach, relieve colic, and assist in the expulsion of flatus. They are absorbed unchanged into the blood and produce leucocytosis, excretion taking place through the lungs, skin, and kidneys. During excretion by the bronchioles they act as expectorants, assisting in the expulsion of mucus; excretion by the skin causes some diaphoresis, and may give rise to mild skin eruptions, this being especially common with oil of copaiba. The most important action of many volatile oils is exerted upon the genito-urinary tract after excretion by the kidneys. They produce dilatation of renal vessels and consequent diuresis, and appear in the urine in combination with glycuronic acid. They lessen inflammatory exudation and retard the putrefaction of the urine. Large doses set up inflammation of the bladder and urethra, and small doses may exaggerate pre-existing inflammatory conditions; the oils are therefore given only in the sub-acute stages of disease. For internal use the less irritant oils are used, such as copaiba, cubeb, and sandal wood oils, and the balsams. Oil of turpentine is employed externally as a counter-irritant and rubefacient, in the form of Linimentum Terebinthinae and Linimentum Terebinthinae Aceticum, in chronic rheumatism and various chest affections. To relieve deep-seated pain and inflammation, as in peritonitis, flannels are wrung out of hot water, sprinkled with oil of turpentine and applied to the seat of pain. The oil is used as an inhalation in chronic bronchitis, but terebene is usually preferred. Internally, the oil is given in small doses in bronchitis and phthisis, and to arrest haemorrhage from the lungs, nose, uterus, kidneys, or intestine, but its use for the latter purpose is based on misconception. Large doses are purgative and anthelmintic; to prevent absorption they are best given with castor oil. Oil of turpentine expels tape worms and thread worms; for the latter it may be used as Enema Terebinthinae, with, or without, castor oil. It is given internally, and by enema, in the tympanites of typhoid fever. The oil may be administered in mixture form, emulsified with half its weight of powdered gum acacia, or one-fourth its weight of powdered tragacanth, by the processes described in the monographs on those gums; it is also given enclosed in gelatin capsules. Oil of turpentine has been given as an antidote in cases of poisoning by phosphorus; but, though it combines with the phosphorus to form compounds of a less toxic nature than that substance, the results have not been entirely satisfactory. In cases of poisoning by large doses of oil of turpentine, emetics and demulcent drinks should be given, with magnesium sulphate to promote purgation and opium to relieve pain.

Dose.—1 to 6 decimils (0.1 to 0.6 milliliters) (2 to 10 minims); as an anthelmintic, 12 to 15 mils (3 to 4 fluid drachms).

PREPARATIONS.

Confectio Terebinthinae, B.P., 1885.—CONFECTION OF TURPENTINE.

Oil of turpentine, 25; liquorice root, in powder, 25; clarified honey, sufficient to produce, by weight, 100. Rub the oil with the liquorice, add the honey, and mix to a uniform consistence. Confection of turpentine is. diuretic and antispasmodic. Large doses are purgative and anthelmintic. Dose.—4 to 8 grammes (60 to 120 grains).

Emulsum Olei Terebinthinae, U.S.P.—EMULSION OF OIL OF TURPENTINE.

Rectified oil of turpentine, 15; expressed oil of almond, 5; syrup, 25; gum acacia, 15; water, to 100. Average dose.—4 mils (1 fluid drachm).

Enema Terebinthinae, B.P., 1885.—ENEMA OF TURPENTINE.

Oil of turpentine, 6.25; mucilage of starch, sufficient to produce 100. Mix the oil of turpentine with the mucilage, by trituration. This enema is used to evacuate the bowel and remove flatulent distension, the quantity sufficient for one application being 480 mils (16 fluid ounces).

Linimentum Album, B.P.C.—WHITE LINIMENT. Syn.—Linimentum Terebinthinae Compositum; Egg Liniment.

Oil of turpentine, 40; acetic acid, 8.5; with oil of lemon, yolk and white of egg, and distilled water to 100.

Linimentum Album, C.F.—Same as Linimentum Terebinthinae Aceticum, N. F.

Linimentum Terebinthinae, B.P.—LINIMENT OF TURPENTINE.

Soft soap, 7.5; camphor, 5; oil of turpentine, 65; distilled water, sufficient to produce 100. Add 10 of distilled water to the soft soap, mix, and add gradually, with constant trituration, a solution of the camphor in the oil of turpentine; when the mixture thickens to a creamy consistence add sufficient distilled water to make up to the required volume. Liniment of turpentine is used as a rubefacient and counter-irritant in rheumatism and chronic inflammation of the joints.

Linimentum Terebinthinae, U.S.P.—TURPENTINE LINIMENT.

Oil of turpentine, by weight, 35; resin cerate, 65.

Linimentum Terebinthinae Aceticum, B.P.—LINIMENT OF TURPENTINE AND ACETIC ACID.

Oil of turpentine, 44; glacial acetic acid, by weight, 11; liniment of camphor, 44. This liniment resembles Linimentum Terebinthinae in its action, but it is more easily rubbed into the skin.

Linimentum Terebinthinae Aceticum, N.F.—ACETIC TURPENTINE LINIMENT. Syn.—Linimentum Album; Stokes' Liniment; St. John Long's Liniment.

Oil of turpentine, 100 mils; the yolk and white of one fresh egg; oil of lemon, 4 mils; acetic acid (U.S.P.), 20 mils; rose water (U.S.P.), 85 mils. Beat the egg with the oils, then incorporate the acetic acid and rose water. Shake the mixture before dispensing.

Linimentum Terebinthinae Ammoniatum, B.P.C.—AMMONIATED LINIMENT OF TURPENTINE.

Oil of turpentine, 1; ammoniated liniment of camphor, 4.

Linimentum Terebinthinae Dilutum, B.P.C.—DILUTED TURPENTINE LINIMENT.

Liniment of turpentine, 50; olive oil, 50.

Unguentum Terebinthinae, B.P., 1885.—TURPENTINE OINTMENT.

Oil of turpentine, by weight, 8; resin, in coarse powder, 1; yellow beeswax, 4; lard, 4. Melt the resin, beeswax, and lard on a water-bath, add the oil of turpentine gradually, remove from the source of heat, and stir constantly until the ointment solidifies. Turpentine ointment was formerly used as a mild counter-irritant and rubefacient for rheumatic joints, etc.

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