Cinchoninae Sulphas. Cinchonine Sulphate.
Related entry: Red Cinchona Bark
C38H46N4O6S,2H2O = 722.51.
Cinchonine sulphate, (C19H22N2O)2,H2SO4,2H2O, is the salt of a base found in cinchona bark. It is official in the U.S.P. It occurs in white, shining crystals, without odour, but with a bitter taste. It is neutral to litmus. It contains two molecules of water of crystallisation when crystallised from water, but only one when crystallised from alcohol. Melting-point, 198.5°. It should not give more than a slight colour to sulphuric acid, and should not lose more than 5 per cent. of its weight when dried at 100°. Not more than a slight fluorescence should be noticeable in a solution (1 in 1000) in dilute sulphuric acid (limit of quinine and quinidine). It should be slowly but completely soluble in 80 of chloroform (limit of quinine or cinchonidine).
Soluble in water (1 in 85), alcohol (1 in 9). The solubility of cinchonine sulphate is increased by the addition of diluted sulphuric acid.
Action and Uses.—Cinchonine is a bitter tonic and antiperiodic, less powerful than quinine, and less toxic; it differs in action from quinine in that it increases reflexes, and in very large doses may even cause convulsions. It is a cheap substitute for quinine, for use as a prophylactic in malaria. On account of its nauseous and very bitter taste it is better administered in pills; these may be prepared with glucose or glycerin of tragacanth.
Dose.—½ to 6 decigrams (1 to 10 grains).