Influence of humidity on radiochemical purity of 99mTc-ECD and 99mTc-Sestamibi

Influence of Storage Temperature on Radiochemical Purity of 99mTc-Radiopharmaceuticals

“…The instructions concern not only the reconstitution procedure of the kit formulation, but also the storage conditions and the associated quality control procedures. Environmental factors, such as temperature, humidity, and/or light, intrinsic factors, such as chemical-physical properties of the reagents and excipients present in the kit formulations, pharmaceutical composition, quality of the generator eluted [ 99m Tc]NaTcO 4 , etc., could compromise the radiochemical purity of technetium-99m radiopharmaceuticals [1,2,3,4]. In particular, these factors could cause the formation of chemical impurities inducing phenomena such as hydrolysis and oxidation-reduction reactions.…”

“…Among the impurities, residual 99m Tc-pertechnetate, as consequence of non-reduction, and the reduced hydrolyzed technetium-99m [ 99m Tc]TcO 2 , due to the pertechnetate reduction, but not the complexation of the technetium-99m [5], lead to consequent radiochemical purity (RCP) loss of the final radiopharmaceutical. The effect of many listed factors on RCP of some 99m Tc-radiopharmaceuticals have been investigated in the past, e.g., the technetium-99 presence excess in solution [2]; the humidity influence on radiochemical purity of [ 99m Tc]Tc-ECD and [ 99m Tc]Tc-MIBI [1]; the saline storage condition, used for the preparation of [ 99m Tc]Tc-HMPAO [6]; and the effect of increased temperature on the labelling efficiency of some 99m Tc-radiopharmaceutilcals [7]. In particular, Maksin et al exposed some compounds, such as pyrophosphate (PyP), dicarboxypropane diphosphonate (DPD), dimercaptosuccinate (DMS), and Sn-colloid, at 37 °C for different time intervals before labelling with 99m Tc-pertechnetate.…”