Quininae Hydrobromidum Acidum. Acid Quinine Hydrobromide.

Related entries: Quinine - Red Cinchona Bark

C₂₀H₂₆N₂O₂Br₂, 3H₂O = 540.116.

Synonym.—Quinine Dihydrobromide.

Acid quinine hydrobromide, C₂₀H₂₅N₂O₂, 2HBr, 3H₂O, may be prepared by dissolving 100 of quinine sulphate in 800 of water containing 67.5 of dilute sulphuric acid of specific gravity 1.110 to 1.114. To this solution, boiling, is added a solution of 76 of crystallised barium bromide in 200 of water, in small portions at a time, and with constant stirring. When all is added the solution is allowed to boil for a short time, and then set aside to clear. The supernatant liquid is tested for barium salt, and adjusted if necessary with a solution of acid quinine sulphate so that a very slight excess of the latter finally remains; filtered, evaporated at 60° to 300 by weight, and allowed to crystallise in the cold. The crystals after draining on filter paper arc, carefully dried. It contains 60 per cent. of anhydrous quinine, 30 per cent. of hydrobromic acid, and to per cent. of water. Acid quinine hydrobromide occurs in the form of yellowish or white, prismatic crystals or powder. The aqueous solution reddens blue litmus; it should not be rendered turbid by diluted sulphuric acid (absence of barium salt).

It gives the thalleioquin reaction, and should respond generally to other tests described under Quinina.

Soluble in cold water (1 in 7), very easily soluble in boiling water and in alcohol.

Action and Uses.—On account of its ready solubility, this salt is suitable for the preparation of non-irritating solutions (1 in 10) for hypodermic use (see Quininae Hydrochloridum Acidum). Doses of 3 to 5 grains are injected daily in malaria, either subcutaneously over the splenic area, or intramuscularly in the buttock. The acid salts of quinine when given in pill or capsule form are more readily soluble in the stomach than the neutral Salts. Acid quinine hydrobromide is incompatible with potassium iodide.

Dose.—½ to 6 decigrams (1 to 10 grains).

PREPARATION.

Syrupus Quininae Hydrobromidi, B.P.C.—SYRUP OF QUININE HYDROBROMIDE.

Contains 1 grain of acid quinine hydrobromide in 1 fluid drachm. Dose.— 2 to 4 mils (½ to 1 fluid drachm), in water.

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