Bismuth Citrate for treating infections of the stomach lining

 

Bismuth compounds have been used for over 200 years to treat diseases of the gastrointestinal tract (disinfection and pH regulation). The exact mechanism of Bi pharmaceuticals is still essentially unknown.

 

Usually basic Bi(III) citrate, Bi(III) nitrate or Bi(III) salicylate are used. In aqueous solution the compounds have a strong tendency to build hydroxo-bridged cage and and polymeric structures.

Cage Structure of
[Bi6O4(OH)4](NO3)6 · 6 H2O

Section of the Polymer Structure of Na2[Bi2(citrate)2]

It is thought that the efficency of the compounds depends on the pH dependent formation of polymer layers. Bi(III) citrate complexes are stable between pH 3.5 - 7.5 but form different structures.