132 



United States Pharmacopoeia method for belladonna in the details of extracting' the 

 drug, but instead of shaking out the ethereal extract with acid, the former is to be 

 evaporated, ammonia expelled by repeated addition of a few cubic centimeters of 

 ether and evaporation, and the impure residue titrated. It might either be dis- 

 solved in alcohol diluted with water and titrated with acid, or dissolved in excess of 

 standard acid and the excess of acid titrated with standard alkali, preferably with 

 iodeosin indicator. This method, he thinks, could be adapted for many alkaloidal 

 drugs. Professor Ruddiman criticises the use of decinormal acid, especially in titrat- 

 ing an alkaloiol of such high molecular weight as aconitin, where a slight difference 

 in measurement seriously affects the result. 



In Method II as well as in I, Mr. Lyons obtained a further yield of about 0.1 per 

 cent of alkaloid by shaking out with chloroform following the final extraction of the 

 alkaline liquid with ether. Mr. Pearson redissolved the alkaloidal residues from the 

 gravimetric determinations in (II) in acid and purified by submitting them to a shak- 

 ing-out process with ether, obtaining much lower results, viz, 0.312 and 0.315 per cent. 



In view of the fact that both methods gave practically the same average volumetric 

 result and variability, the greater convenience and rapidity of Method II are in its 

 favor. 



BELLADONNA LEAVES. 



This sample was delivered as No. 60 powder. The following proportions passed 



through the respective sieves: 



Grams. 



No. 60 40 



No. 50 35 



No. 40 25 



Total 100 



A considerable amount of coarser powder than the Pharmacopoeia permits in assay 

 samples of belladonna leaves was present. By Method I (U.S. P.) the few gravimetric 

 results reported varied exceedingly, none of them coming within 10 per cent of the 

 average, and only 14 per cent within 15 per cent of the average. Of the volumetric 

 results, 41 per cent came within 10 per cent and 65 per cent within 15 per cent of the 

 average. By (II) gravimetric, 86 per cent of the few results were within 10 per cent; 

 also 86 per cent within 15 per cent of the average. Of the volumetric results by (II) 

 39 per cent came within 10 per cent, and 73 per cent within 15 per cent of the average. 

 The average results by (I) are slightly higher than by (II), but both are somewhat under 

 the United States Pharmacopoeia standard of 0.30 per cent. A slight impurity in the 

 residues is indicated by the higher gravimetric results. In (I) Mr. Hankey used 2 cc 

 of ether to assist solution of the alkaloidal residue in acid, expelling it by gentle warm- 

 ing before titration. J. G. Francis and Parker used 50 cc more ether-chloroform mix- 

 ture than directed to exhaust the drug. It has been observed in the Drug Division 

 when assaying belladonna leaves and root and coca leaves by the pharmacopceial 

 method n that a large portion of the last 50 cc of solvent mixture which is intended to 

 complete the percolation has to be used in rinsing the drug into the percolator. The 

 drug should be packed after it is all transferred and percolation carried to practical 

 exhaustion. The combined acid solutions obtained by shaking with the percolate 

 should be shaken with fresh solvent in small portions until no more color is removed 

 before making alkaline and shaking out the alkaloid. Instead of measuring out 3 cc 

 of decinormal sulphuric acid to dissolve the alkaloid, a number of workers in such 



Workers in the Division of Drugs recommend cylindrical nursing bottles (8 

 ounces) which taper to the neck without any shoulder instead of Erlenmeyer flasks 

 for digesting the drug with solvent, as the former are more easily clamped on a me- 

 chanical shaker. 



