C34H48N2O10S, 2H2O = 712.506.
Hyoscyamine sulphate, (C17H23NO3)2, H2SO4, 2H2O, is a salt of an alkaloid contained in henbane, scopola, and other Solanaceous plants. Hyoscyaminae Sulphas, U.S.P., is anhydrous. Hyoscyamine sulphate occurs as a white, crystalline powder, without odour, but with a bitter, acrid taste. Its aqueous solution is laevorotatory and neutral to litmus. The tests described under Hyoscyaminae Hydrobromidum are also applicable to this salt. The B.P. melting-point is 206° (U.S.P., 198.9°), but the commercial salt has a lower melting-point; it should not, however, be below 200°. The melting-point of the aurichloride is 160°. The sulphate should leave no residue on ignition. Hyoscyamine sulphate should be kept in well-stoppered, amber-coloured bottles.
Soluble in water (2 in 1), alcohol (1 in 4.5), very slightly soluble in ether or chloroform.
Action and Uses.—Hyoscyamine is intermediate in its action between atropine and hyoscine. It causes less stimulation of the central nervous system than atropine, and is a weaker sedative and hypnotic than hyoscine (see Atropina and Hyoscinae Hydrobromidum). It has the same action peripherally as atropine, but is more powerful. The action of atropine is the resultant of the action of equal amounts of laevo-hyoscyamine (the natural alkaloid) and dextro-hyoscyamine, laevo-hyoscyamine having a much more powerful action than dextro-hyoscyamine on nerve endings. Hyoscyamine sulphate is administered hypodermically, or given in pills for mental excitement and insomnia, especially in delirium tremens and mania. Doses of 0.6 milligram (1/100 grain) are recommended in sea-sickness, one every hour, if required. The official dose is often exceeded; as much as 6 milligrams (1/10 grain) may be given in mania.
Dose.—1/3 to 2/3 milligram (1/200 to 1/100 grain).
The British Pharmaceutical Codex, 1911, was published by direction of the Council of the Pharmaceutical Society of Great Britain.