hyoscyamin (hi-o-si-am'in). i

A crystal lin alkaloid, (C17H23NO3), a levorotary stereo-isomere of atropin, obtained from various solanaceous plants and in various degrees of purity as found in the shops, or sometimes in the amorphous form. Pure levorotary hyoscyamin acts twice as strongly as atropin. on nerve endings, but with the same strength on the central nervous system of mammals. In addition to the difficulty of obtaining pure hyoscyamin, it has the disadvantage of being converted very readily into atropin. Dextrorotary h. is also known. 2. Of the eclectics, a concentration obtained from Hyoscyamus niger. h. hydro bromid. A soluble salt, having the actions and uses of hyoscyamin. h. sulphate. The neutral sulphate, (CiTr^NOa^.mSGNt. This salt of h. is found in several degrees of purity. That recognized by the U. S. Ph. is in indistinct crystals or powder, suggesting some degree of impurity. It is also obtainable in a high degree of purity, though distinctly crystalline and in an amorphous state. The amorphous and the crystalline appear to differ in degree of activity. [U. S. Ph., Br. Ph.] [Lat., hyoscyamina.1