The Ephedrine Assay of Chinese Ephedra.*

As set forth in a recent note we have shown that Chinese Ma Huang is obtained from various species of Ephedra, E. eguisetina, Bunge; E. sinica, Stapf ; and E. mahuang, Liu. So far there has been no differentiation made between the various samples of this drug which occur upon the Chinese market. However, irrespective of the possible variation in the drug samples we consider i t is essential that there be made a critical statement of the methods of assay and the results as found and studied by us over a long period of time. It has been pointed out by Chou that ephedrine is a stronger base than ammonia, turning i t out from its salts; hence i t is a matter for critical study to show how suitable the U. S. P. belladonna assay method may be as used by various workers. The chemical laboratory of the American Medical Association has stated that when ephedrine is shaken out with ammonia and chloroform there is a reaction so that the hydrochloride is obtained instead of the free alkaloid. In examining methods for separating ephedrine and pseudo-ephedrine hydrochloride we showed clearly that the use of ammonia to liberate the alkaloidal bases was open to question. Ammonia, when added to the extraction in limited amount sufficient only to make the fluids quite alkaline to litmus, did not produce the pure alkaloid. We have now studied the effects of the addition of molecular equivalents of strong ammonia and find that when the ammonia is present in very large excess the alkaloids are set free. Hot and cold methods of extraction were made, also direct alkalinization of the powdered drug with potassium carbonate or soda ash, and adsorption by fuller’s earth, which confirmegin a general way the high figures obtainable by these various methods.