20 



BISMUTHI SUBCARBONAS. 



CAFFEINA. 



The other official bismuth preparations are: Bismuthi et Ammonii Citras, Bis- 

 muthi Betanaphtholas, Bismuthi Subgallas, Bismuthi Subnitras, Bismuthi Subsalicylas 

 all of which are either superfluous or of questionable utility. 



CAFFEINA. 



Caffeine is a xanthine compound derived from the dried seeds of Coffea arabica 

 (Fam. Rnbiacece), a native of Arabia. It is also obtained from the leaves of Thea 

 smcnsis (Fam. Ternstrceuriacccc}; an Asiatic shrub. It also occurs in other plants, 

 and may be prepared synthetically. 



By treating Caffeine with citric acid in hot water there results a substance of 

 loose chemical structure known as Citratecl Caffeine. 



Properties: 

 Caffeine : 



Appearance 



Color 



Odor 



Taste 



Solubility : 



4 H 2 O 



8 H 2 



25 H 2 O 



50 H 2 O 



Hot HoO 



CoH fi OH ... 



Citrated Caffeine: 



Appearance 



Color 



Odor 



Taste 



Solubility : 



4 H 2 O 



8 H 2 



25 H 2 O 



50 H 2 O 



Hot H 2 



C 2 H 5 OH ... 



Caffeine is a stimulant to respiration, kidney activity, and cerebrospinal reflexes. 

 It also seems to improve vascular conditions when the circulatory system is function- 

 ally enfeebled. Dose of Caffeina, 0.15 Gm. ; of Caffeina Citrata, 0.3 Gm. 



Other Official Preparations. 



Caffeina Citrata Effervescens. Dose, 4 Gm. 



Caffeinae Sodio-Benzoas. Dose, by mouth, 0.3 Gm. ; hypodermic, 0.2 Gm. 



This latter substance is a mixture of about 46% anhydrous caffeine and about 

 54% sodium benzoate. 



Two other xanthin products are the official Theophyllina, found in small amounts 

 in tea leaves, and also made synthetically ; and Theobromine, derived from Theobroina 

 Cacao, with an official salt, Theobrominse Sodio-Salicylas. These two substances are 

 both dimethylxanthine. They possess but little advantage over the trimethylxanthine 

 Caffeine, though a more marked diuretic action, with no cerebral effect, is claimed for 

 theobromine. 



