492 OLEO-RESINS 



PAR! COPAIBA 



Description. Para copaiba is a thin, clear, bright yellow liquid 

 quite free from any fluorescence. The specific gravity varies from 

 0-917 to 0-980, but is usually low. In accordance with the greater 

 fluidity of this variety the percentage of volatile oil is high, viz. from 

 about 55 to 90 per cent. In other characters the drug resembles 

 the Maracaibo variety. 



Constituents. Para copaiba also consists essentially of volatile oil 

 and resin. 



The resin consists of amorphous resin-acids associated with crystal- 

 line paracopaivic acid (2 per cent.), homoparacopaivic acid, and two 

 resenes. 



The volatile oil appears to be identical with that of Maracaibo 

 copaiba, but the resins are certainly not. 



AFRICAN COPAIBA 



African copaiba, the botanical source of which is not known, 

 is imported from the Niger basin in West Africa. It is a rather 

 dark yellow, slightly fluorescent oleo-resin possessing an aromatic, 

 piperaceous odour and frequently depositing crystals on standing. 

 The specific gravity varies from 0-985 to 1-000. It contains about 

 40 per cent, of volatile oil and 60 per cent, of resin (including the 

 crystalline substance). 



Constituents. The oil boils at 260 to 275 and differs essentially 

 from the oil of South American copaiba in being dextrorotatory, the 

 rotation in 100 mm. tube being about 10 21'. 



The crystalline deposit consists of illurinic acid identical with that 

 obtained from Maracaibo copaiba. The remainder of the resin consists 

 of amorphous resin-acids, fluorescent substance, &c. 



ADULTERANTS or COPAIBA 



The British Pharmacopoeia (1914) recognises any variety of South 

 American copaiba containing about 45 per cent, of volatile oil, and 

 therefore excludes thin Para varieties containing much over that 

 proportion but admits varieties of the Maracaibo type. The drug 

 is, however, not infrequently sophisticated to bring it within the 

 official limits. 



The following are the chief adulterants and the means of detecting 

 them. 



Fixed vegetable oils, such as castor oil, render the resin left after 

 evaporation of the volatile oil (best at a temperature of about 120 

 to 130) tough or pasty, whereas it is usually (in Maracaibo copaiba) 



