Abstract
Papaverin is one of the principal primary opium alkaloids in point of both quantity and pharmacologic interest. Its amount in opium varies from 0.11 to 0.22 per cent. The alkaloid was discovered by Merck in 1848. It crystallizes in white prisms, with a melting point of 147 C. The crystals are insoluble in water and alkalis, difficultly soluble in ether and benzol, but easily soluble in warm alcohol, chloroform and acetone. It is tasteless, is neutral in reaction with litmus and is polariscopically inactive. The alkaloid easily combines with acids, forming salts, and it is the sulphate and more especially the hydrochlorid that are chiefly used in physiologic work. These salts can be obtained on the market in a very pure chemical state, and are soluble in water and in normal saline. Like all the other opium alkaloids, papaverin is characterized by color reactions by which