Radiopharmaceutical Evaluation of Tc-99m Hydroxymethylene Diphosphonate

Abstract

The radiopharmaceutical purity and stability of Tc-99m hydroxymethylene diphosphonate were studied over a ten-week period using miniaturized chromatography to evaluate levels of both free pertechnetate and hydrolyzed reduced Tc-99m. Results showed good preparation stability up to 4 hr postformulation even when 400 mCi of activity was added. After 4 hr postformulation, some inconsistent radiopharmaceutical degradation was observed. Both old and new formulations of Tc-99m hydroxymethylene diphosphonate were very sensitive to air introduction. The new formulation was less sensitive to air oxidation because of higher stannous chloride and gentisic acid levels. We stress careful technique when dispensing Tc-99m hydroxymethylene diphosphonate in order to minimize any air introduction.