129 



THE ASSAYING OF ALKALOIDAL DRUGS. 

 By C. E. PARKER. 



The original drug assay methods of the last revision of the United States Pharma- 

 copeia, (in t he whole, fairly represented the existing status of this branch of chemical 

 unuK ris. They were formulated under the instruction of the convention for revising 

 tin- I'harmai -ofxi -ia that assay processes should be "reasonably simple (both as to 

 nu't hods and apparatus required) and lead to fairly uniform results in different hands." 



The probability being somewhat vague that they would be made the basis for gen- 

 eral l.-u-al regulation, a high degree of accuracy did not appear important, and similar 

 moderate standards of requirement have possibly influenced the evolution of drug 

 assay methods generally. . After the passage of the federal food and drugs act of June 

 30, 1906, the committee on revision made a number of corrections and modifications 

 in the text of the Pharmacopoeia that it might better meet the new requirements. 



Judged from the point of view of the official chemist and prospective expert witness 

 before the courts, the cooperative work as far as it has gone has not shown that the 

 pharmacopu'ial methods lead to fairly uniform results in different hands. This is 

 probably due more to lack of detail in the instructions than to any fundamental 

 defects in the methods. It is evident that losses occurring at certain stages in the 

 processes may be prevented by suitable alterations in the methods, and that the 

 unfavorable results on some drug samples may, to a considerable extent, be attributed 

 to the i>o\vder not being of a proper fineness. 



'I'll- samples sent out this year were from supplies ordered to be according to the 

 I'nited Mate- Phannacopieia. both as to assay and fineness of powder. The sample 

 oi belladonna root has been criticised as being a finer powder than specified by the 

 Pharmacopo-ia, and, therefore, likely to giv< higher results and too favorable reports 

 on the met ho, 1 < ttliei samples of drugs have been said to be too coarse, and, there- 

 unt'air to tin- method-. The point is well taken, but the only way to obtain a 

 powder oi" exactly the pharrnacopu'ial si/.e would be to separate with suitable screens 

 all larger and smaller particles produced by the mill, and such a product would not be 

 -entati\e i.i tin- ..ri-jinal drui;. The proper solution of the difficulty would seem 

 to be the pro\ i.-ion of -nitable apparatus for grinding all drug samples for assay at least 

 as fine as the Pharmacopoeia requires and as much finer as experience shall show to be 

 expedient 



The theoretical ..bjeetion- to the aliquot method of extraction may be justified when 

 the grosser imperfection- in the methods have been eliminated, but so far results fail 

 to demonstrate the -nperior reliability of the total extraction method, and judgment 



mil.-t be Ml-pellded. 



It was thought advisable to traverse again the ground covered last year when only 

 three anal\.-t- participated, comprising methods for the assay of aconite root, bella- 

 donna 1- a\e r . belladonna root, cinchona bark (yellow and red), cocoa leaves, colchi- 

 cum conn, and colehiciim seeds. Samples of these drugs delivered as being of phar- 

 macopceial quality and as ground to the fineness of powder specified in the respective 

 pharmacopceial assay method- were supplied to all collaborators with the following 

 dire, tion-, and instructions that all calculations and solutions except as otherwise 

 specified be based on the data of the United States Pharmacopoeia, eighth revision, 

 with the additions and corrections dated May 1 and June 1, 1907. 



The provisional methods appearing in Bulletin 107, revised, pages 258-259, were 

 slightly modified in accordance with the experience of last year. Only the modifica- 

 tions are reprinted bflon- and the changes are italicized. 

 73673 Bull. 12209 9 



