42 POWDERED VEGETABLE DRUGS 



6. Quantitative Limits of Harmful Adulterants. Any U. S. P. 

 drug or N. F. preparation containing any foreign substance or sub- 

 stances, which in themselves have toxic or harmful effects, or effects 

 different from that of the official drug or preparation, if present in 

 appreciable amounts (as determined by chemical, or microscopical, 

 or bacteriological tests), said drug or preparation shall be deemed 

 adulterated, no matter whether such substances are accidentally or 

 intentionally added or whether they have developed within or upon 

 the drug (as bacteria, yeast cells, mold, mites and other parasites). 



7. Tests for Determining the Quality and Purity of Drugs. The test 

 methods of the U. S. P., or desirable modifications thereof, shall be 

 used, with such other methods (chemical, macroscopical, microscopical, 

 and bacteriological) as may become necessary or desirable. 



8. Fineness of Vegetable Drugs for Percolation. The U. S. P. 

 specifies the exact fineness of the vegetable powders intended for 

 percolation. However, based upon the examination of numerous 

 samples of vegetable drugs it is evident that many, in fact most of 

 the commercial powders, are so variable in the degree of fineness that 

 it is impossible to obtain uniform products from percolation. In 

 many of the samples examined the fineness varied (in the same sample) 

 from a very fine meal to particles from % to 2^-inch in diameter or 

 length. The U. S. P. specifies the exact fineness of leaf, root, stem, 

 wood, flower, fruit, seed, etc., intended for percolation in the prepara- 

 tion of tinctures and fluid extracts, and pharmacists should comply 

 with such requirements. The U. S. P. should specify the exact diameter 

 of mesh and diameter of the wire, hair or other material used in sieve 

 construction. This is a matter of great importance and should receive 

 the prompt attention of the U. S. P. Revision Committee. 



Retail pharmacists are supposed to reduce the commercial vege- 

 table powders to the required uniform fineness, but unfortunately this 

 is generally not done. Wholesale drug dealers could prepare the pow- 

 ders more readily but these also fail to do so. 



To label a powder "for percolation" whether or not the fineness 

 required by the U. S. P. is given in terms of the sieve mesh, is unlaw- 

 ful unless such powder is of the fineness specified by the U. S. P. 

 for making the percolation. 



9. Compensating for Loss in Drug Action. As is generally known, 

 drugs of all kinds lose in physiological activity and therapeutic value 

 with age. Some tests have been made indicating the rate of such loss 

 with regard to some of the more important crude drugs and the pre- 

 parations made therefrom. Some pharmacopoeias specify the time 

 when certain drugs are to be discarded because of age. The U. S. P. 



