Effect of source and age of sodium pertechnetate Tc 99m on radiochemical purity of technetium Tc 99m exametazime.
The radiochemical purities of technetium Tc 99m exametazime prepared with one-hour-old or six-hour-old sodium pertechnetate Tc 99m from two manufacturers' generators were compared. Eluates from each manufacturer's generators were diluted immediately to provide two solutions of sodium pertechnetate Tc 99m. For the one-hour-old solution, eluate was diluted with 0.9% sodium chloride injection to a concentration of radioactivity of 38 mCi in 5.5 mL and used one hour later. For the six-hour-old solution, eluate was diluted to 65 mCi in 5.5 mL and used six hours later. Technetium Tc 99m exametazime was prepared by injecting 5.0 mL of one of the solutions into an exametazime kit to provide 30 mCi of technetium Tc 99m in 5.0 mL. At 2, 30, and 60 minutes after reconstitution of each kit, the radiochemical purity was measured by high-performance liquid chromatography with radiation detection. At two minutes, all the preparations retained high radiochemical purities. However, at 30 and 60 minutes, the radiochemical purities of technetium Tc 99m exametazime prepared with six-hour-old sodium pertechnetate Tc 99m were significantly lower than those of technetium Tc 99m exametazime prepared with one-hour-old sodium pertechnetate Tc 99m. Similar results were found for each manufacturer's generators. The radiochemical purity of technetium Tc 99m exametazime was affected by the age of the sodium pertechnetate Tc 99m from which it was prepared but not by the generator from which the sodium pertechnetate Tc 99m was obtained.
Royal Infirmary of Edinburgh, United Kingdom.
A M
AM
Millar
D006801:Humans; D015609:Organotechnetium Compounds / Q000592:standards*; D010091:Oximes / Q000592:standards*; D011876:Radionuclide Generators; D013670:Sodium Pertechnetate Tc 99m; D019690:Technetium Tc 99m Exametazime; D013997:Time Factors
D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D013670:Sodium Pertechnetate Tc 99m