Morphinae Tartras, B.P. Morphine Tartrate.

Related entries: Opium - Poppy Capsules - Cotarnine - Cotarnine Hydrochloride - Morphine - Morphine Acetate - Morphine Hydrochloride - Morphine Sulphate - Morphine Tartrate - Narceine - Narcotine - Red poppy petals - Meconic acid

C₃₈H₄₄N₂O₁₂, 3H₂O = 774.420.

Morphine tartrate, (C₁₇H₁₉NO₃)2C₄H₆O₆, 3H₂O, may be prepared by neutralising morphine suspended in water with tartaric acid, evaporating the solution at a gentle heat, and crystallising. It occurs in white, acicular crystals, or as a white powder consisting of fine nodular tufts of minute, odourless, closely aggregated, acicular crystals, having a bitter taste. It is a useful salt on account of its stability and ready solubility in water. Commercial samples have been found to contain variable proportions of the sparingly soluble acid tartrate. Morphine tartrate effloresces at 20°, and loses all its water of crystallisation at 130°. Its aqueous solution is not precipitated by caustic alkalies or carbonates. It should respond to the identification tests given under Morphina. Assayed gravimetrically it should yield 73.5 per cent. of anhydrous morphine.

Soluble in water (1 in 10), sparingly soluble in alcohol, almost insoluble in ether, chloroform, or carbon disulphide.

Action and Uses.—Morphine tartrate has the general properties of the salts of morphine, and is employed in the preparation of Injectio Morphinae Hypodermica, this salt having been substituted for the acetate on account of the greater stability of the tartrate. Tablets of morphine tartrate are made in various strengths for the preparation of solutions for hypodermic use. Liquor Morphinae Tartratis contains 1/10 grain in 11 minims, and is used similarly to the corresponding solution of morphine hydrochloride. Atropine sulphate (1/200 or 1/100 grain) is frequently added to morphine injections to increase their analgesic effect, to lessen their tendency to cause constipation, and especially to reduce spasm. Morphine tartrate is incompatible with alkalies, alkali earths, salts of the heavy metals and vegetable astringents. In cases of poisoning by morphine tartrate the antidotes are those of morphine.

Dose.—8 to 30 milligrams (⅛ to ½ grain).

PREPARATIONS.

Injectio Morphinae et Atropinae Hypodermica, B.P.C.—HYPODERMIC INJECTION OF MORPHINE AND ATROPINE.

Five decimils (0.5 milliliters) contain 3 centigrams of morphine tartrate and 0.6 milligram of atropine sulphate (½ grain and 1/100 grain, respectively, in 8 minims). The addition of atropine lessens the tendency to depression and constipation. Dose.—1 to 5 decimils (0.1 to 0.5 milliliters) (2 to 8 minims).

Injectio Morphinae Hypodermica, B.P.—HYPODERMIC INJECTION OF MORPHINE.

Morphine tartrate, 5 per cent. Three decimils (0.3 milliliters) contain 15 milligrams of morphine tartrate (1 grain in 22 minims). Dose.—1 to 3 decimils (0.1 to 0.3 milliliters) (2 to 5 minims).

Liquor Morphinae Tartratis, B.P.—SOLUTION OF MORPHINE TARTRATE.

Morphine tartrate, 1; alcohol, 25; distilled water, sufficient to produce 100. Dissolve the morphine tartrate in the alcohol, previously mixed with 25 of water, and add sufficient water to produce 100. This preparation has the same action as other solutions of morphine, but it is rarely used. Dose.—½ to 4 mils (10 to 60 minims).

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