Stannous Tin Levels in Commercial Stannous Pyrophosphate: Effect of Different Preparation Methods

Abstract

We determined the stannous tin levels of commercial stannous pyrophosphate preparations in order to evaluate the effects of different preparation methods on the stability of stannous pyrophosphate. Preparation methods included maintaining stannous pyrophosphate at room temperature, refrigerating (2-8° C) preparations after formulation, reconstituting stannous pyrophosphate vials with nitrogen-purged saline, and introducing air into preparations after formulation. Stannous tin levels were determined from 0.5 to 48 hr after formulation using a rapid stannous spot test. Results show that stannous tin levels in all stannous pyrophosphate preparations were within 10% of the manufacturer’s stated levels up to 8 hr after formulation. The only exception was when air was introduced into the preparations; this resulted in a significant reduction in the stannous tin levels within 2 hr after formulation. High stannous tin levels in stannous pyrophosphate preparations can be maintained for up to 8 hr if careful radiopharmaceutical preparation and dispensing techniques are used.