Intramuscular Method of Digitalis Assay. 251 



Our method is to inject one half the total dose into the thickest 

 part of each thigh, the needle being directed diagonally. The 

 finest needle must be used and hemorrhage avoided. Otherwise 

 the procedures are the same as for the Pharmacopeial method. 



Judging by our results, the intramuscular method very largely 

 and, v/e believe, satisfactorily, solves the difficulty of poor absorp- 

 tion. 



table 1. 

 Crystalline Strophanthin (Ouabain). 



Frogs. 



,S. S. S. Dose in Mg./Gm. 



Per Cent. 

 Difference. 





Lymph Sac. 



Intramuscular. 





Lot 1 



.00045 

 .00051 

 .00032 

 .00039 

 .00059 

 .00057 



.00037 

 .00044 

 .00027 

 .00031 

 .00050 

 .00051 



17.8 

 13-8 

 15.7 

 20.6 





" 3 



" 4 



" s 



15.3 

 10.6 



** 6 



Digitalis-Tinctures. 



Lot 1 



.70 

 •59 



•57 

 .49 



18.6 





17.0 



Digitalis-Fluidextr xts. 



Lot 1 



.90 Neg. 

 .60 



.70 

 •50 



22.3 

 16.7 





Digitalin-Merck. 

 Formerly Known as "German." 





.025 



.022] 



12.0 





Table I summarizes the results. In all cases the intramuscular 

 S.S.S. (systolic standstill) dose has been compared with the lymph 

 sac S.S.S. dose. In no instance has the intramuscular dose been 

 found as large as that by the lymph-sac method. 



Tinctures, fluidextracts, digitalin and ouabain have been 

 studied. The last column of the table shows the percentage 

 differences between the lymph sac and the intramuscular S.S.S. 

 doses in corresponding lots of frogs. The effective intramuscular 

 dose of digitalin is 10 per cent, less than by the lymph sac while, 



