Inhibition of Mineralization of Urinary Calcium Phosphate Stones by Sodium Pyrophosphate

Abstract

To understand the biological importance of sodium pyrophosphate and its applicability as inhibitors in urolithiasis disease, we have studied the inhibition efficiency of sodium pyrophosphate towards the mineralization of urinary stone forming minerals like calcium phosphate, in aqueous as well as urinary medium. An attempt has been made to unfold, tentatively, the mechanism of inhibition by this inhibitor. It was an observational experiment. The study was conducted in the chemistry lab of the university department of chemistry, B N Mandal University, Madhepura (Bihar). An experimental model was designed by taking the salt forming solutions; the whole operation took about 40-50 min. At the end, the contents of the beaker were digested in a hot water bath, cooled to room temperature, and centrifuged in small volumes. The total centrifugate was collected, and Calcium and carbonate content of the centrifugate of calcium carbonate mineralization experiments were determined. Sodium pyrophosphate has a moderate inhibition efficiency towards calcium carbonate mineralization. At 0.05 M concentration, sodium pyrophosphate has a net inhibition of 30%, which is 26.65% more than that of water (blank). Compared to water, the percentage inhibition increased by 795.52%. With decreasing concentrations of sodium pyrophosphate, the inhibition efficiency decreases. At very low concentration (0.01 M), its inhibition is only slightly higher than that of water. In urinary medium, sodium pyrophosphate seems to function as a better inhibitor of phosphate mineralization. At 0.05 M concentration, sodium pyrophosphate has a net inhibition of 89.22%, which is 75.36% more than that of urine. It is observed that sodium pyrophosphate solution, under different concentrations, exhibits moderate to good efficiency of inhibition towards mineralization of urinary stone forming minerals like calcium carbonate in aqueous as well as urinary medium.