Formation of Poorly Crystalline and Amorphous Precipitate, a Component of Infectious Urinary Stones: Role of Tetrasodium Pyrophosphate

The present study concerns an important topic regarding the search for new, improved, and effective methods of preventing the development of infectious urinary stones. In this article, the effect of tetrasodium pyrophosphate (TSPP) on the formation of a poorly crystalline and amorphous precipitate in artificial urine in the context of infectious urinary stone formation is studied. The spectrophotometric results suggest that TSPP presence shifts the formation of the poorly crystalline and amorphous precipitate (PCaAP) toward lower pH, which means that PCaAP is formed earlier. In other words, TSPP promotes the formation of PCaAP. Additionally, TSPP causes the formation of calcium pyrophosphate. These results are confirmed by X-ray diffraction and energy dispersive X-ray studies. The experimental results obtained are explained on the basis of theoretical chemical speciation analysis of chemical complexes formed in artificial urine.