C20H27N2O6As, 2H2O = 502.228.
Quinine arsenate, C20H24N2O2H3AsO4, 2H2O, may be obtained by dissolving equivalent quantities of quinine hydrochloride and monopotassium arsenate in hot water, mixing the solutions and boiling; after cooling, the precipitate is collected, washed with cold water, dried, and recrystallised from hot diluted alcohol. Salts of different composition can be obtained by variations in the method employed, but the process described yields the most uniform and stable product, with the formula given above. Quinine arsenate occurs in white, silky needles. The salt contains about 64.5 per cent. of quinine and 28 per cent. arsenic acid.
Sparingly soluble in cold water; easily soluble in hot water.
Action and Uses.—Quinine arsenate is employed as an antiperiodic in malarial conditions. Its action is that of arsenic, as but little quinine is present in any dose which can be employed. It is best administered in pills, prepared by triturating the salt with milk sugar and massing with syrup of glucose. In cases of poisoning by quinine arsenate the antidote recommended for arsenious anhydride should be employed.
Dose.—4 to 8 milligrams (1/16 to 1/8 grain).
The British Pharmaceutical Codex, 1911, was published by direction of the Council of the Pharmaceutical Society of Great Britain.