Du Mez—The Galenical Oleoresins. 
1069 
in the fact that a relatively large amount of volatile oil was 
lost in the removal of the solvent. 
The present edition of the Pharmacopoeia directs that the 
drug be completely exhausted by simple percolation with 
ether. Here, as in the case of the oleoresin of capsicum, the 
extraction of the drug with the aid of some form of continu¬ 
ous extraction apparatus would effect a considerable saving 
in solvent and without injury to the finished product. 
8-9) With respect to the removal of the solvent from the per¬ 
colate, the present edition of the Pharmacopoeia directs that 
this be accomplished in greater part by distillation on a water 
bath and that the remainder be allowed to evaporate spon¬ 
taneously in a warm place, a procedure similar to that de¬ 
scribed in the earlier editions. For reasons, identical with 
those given in the comments on the oleoresin of cubeb (see 
page 1045), it is thought that the pharmacopoeial directions 
should include specific statements with reference to the 
amount of solvent to be recovered by distillation and the tem¬ 
perature at which the remainder is to be removed in order to 
insure greater uniformity in the product obtained. 
10) Upon exposure to the air, a portion of the volatile oil con¬ 
tained in the oleoresin is altered (resinified) or lost through 
evaporation. The preparation should, therefore, be kept in 
well-stoppered bottles. 
Yield 
With respect to the solvents, alcohol (95 per cent.), acetone 
and ether, the yield of oleoresin, in the case of ginger, varies in 
magnitude in the order in which the solvents are mentioned. 
For these menstrua, a minimum yield of 2.57 per cent has been 
reported while the maximum yield has been stated to be as high 
as 11.1 per cent. When petroleum ether is the solvent used, 
the yield is much lower, being only about one-half that obtained 
in the preceding eases. In this connection, the source of the 
rhizomes is a factor of first importance. Thus, it has been 
found that Jamaica ginger usually gives the smallest yield and 
African ginger the highest, while Cochin ginger occupies an 
intermediate position in this respect. These facts will be 
brought out more clearly in the tables which follow. 
