Quininae Hydrochloridum, B.P. Quinine Hydrochloride.

Related entries: Quinine - Red Cinchona Bark

C₂₀H₂₅N₂O₂Cl, 2H₂O = 396-712.

Synonym.—Hydrochlorate of Quinine.

Quinine hydrochloride, or Muriate of Quinine, C₂₀H₂₄N₂O₂, HCl, 2H₂O, may be prepared by double decomposition of barium chloride and quinine sulphate; or by dissolving freshly precipitated quinine in diluted hydrochloric acid until the solution is neutral, and setting aside to crystallise. The salt contains 81.73 per cent. of anhydrous quinine, 9.18 per cent. of hydrochloric acid, and 9.08 per cent. of water of crystallisation, equivalent to two molecules. Quinine hydrochloride is also official in the U.S.P. It occurs in the form of white, silky, glistening, acicular, odourless, crystals, usually larger than those of quinine sulphate, slightly efflorescent in warm air, and having a very bitter taste. On exposure to light it gradually becomes yellowish in colour. Heated at 100° to 120° it loses its water of crystallisation, and at 190° it melts. On complete ignition it burns without leaving any residue (absence of inorganic impurities). Its aqueous solution is neutral or only faintly alkaline to litmus. The concentrated aqueous solution is non-fluorescent, but on considerable dilution a slight fluorescence is perceptible, increased on addition of sulphuric acid, but disappearing on the addition of hydrochloric acid. It gives the thalleioquin reaction and should show only the slightest reactions for sulphates, but none for barium. Concentrated sulphuric acid gives no colouration (absence of easily carbonisable matter); nitric acid should give no red colouration (difference from morphine). In order to detect other cinchona alkaloids, of which not more than traces should be present, dry 3 grammes of the salt at 50° for two hours, dissolve in 30 mils of hot water, in an evaporating dish; next add gradually, and with constant stirring, 1.5 grammes of crystallised sodium sulphate, and evaporate to dryness. The dried residue, which should be neutral, is treated with 30 mils of water, and examined for other cinchona alkaloids, as described under Quininae Sulphas.

Soluble in water (about 1 in 40), boiling water (1 in 1), alcohol (1 in 1), chloroform (1 in 9). The anhydrous salt is very soluble in chloroform. Its solutions become yellowish or brownish on keeping.

Action and Uses.—This salt has the properties of quinine sulphate, but is more easily soluble, and is much more readily absorbed. It is less irritating to the gastric mucous membrane, and contains a larger percentage of alkaloid than the sulphate. For the common properties of quinine salts see tinder Quinina. The hydrochloride is employed as an antiseptic wash for the ear (1 in 120), and in the form of pessary (3 or 5 grains in each with oil of theobroma) in leucorrhoea. It is a better salt of quinine than the sulphate for general use. It is Sometimes used hypodermically as Giemsa's Injection, which consists of quinine hydrochloride, to grammes ethyl-urethane, 5 grammes; and water, to 30 mils; dose, 1.5 mils.

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

PREPARATIONS.

Lotio Quininae, B.P.C.—QUININE LOTION. Syn.—Eau de Quinine.

Quinine hydrochloride, 0.11; chloroform, 0.52: alcohol, 20; glycerin, 1.56: Cologne spirit, 1.56; compound spirit of pimento, 25; tincture of cudbear, 3.12; diluted rose water, to 100. This preparation is used as a hair tonic.

Pessus Quininae, B.P.C.—QUININE PESSARY. 3 grains.

Syrupus Quininae Phospho-muriatis, C.F.—SYRUP OF PHOSPHO-MURIATE OF QUININE.

Potassium bicarbonate, 3.5; magnesium carbonate, 2; precipitated calcium carbonate, 2; quinine hydrochloride, 0.4; strychnine hydrochloride, 0.015; orange flower water, undiluted, 12.5; phosphoric acid (83 per cent.), 12.5; soluble ferric phosphate, 1.6; water, 1.6; syrup, sufficient to produce 100. Mix the orange-flower water with the phosphoric acid, and dissolve the carbonates and alkaloidal salts in the mixture; dissolve the ferric phosphate in the previously warmed water, and mix with the foregoing solution; lastly, add sufficient syrup to make up to 100.

Tinctura Quininae, B.P.—TINCTURE OF QUININE.

Quinine hydrochloride, 2; tincture of orange, 100. Dissolve, and filter if necessary. A useful form of administering the alkaloid as a bitter. Dose.—2 to 4 mils (½ to 1 fluid drachm).

Vinum Quininae, B.P.—QUININE WINE.

Quinine hydrochloride, 0.228; orange wine, 100. Dissolve, set aside till clear, and filter if necessary. Taken as a bitter before meals, to stimulate the appetite and therefore indirectly to improve gastric digestion. Dose.—15 to 30 mils (½ to 1 fluid ounce).

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