Evaluation of the utility of a closed system adapter in the preparation and dispensing of Tc-99m labeled radiopharmaceuticals.

Objectives To determine the stability, sterility, product retention and spill containment of radiopharmaceutical kits and doses compounded and dispensed utilizing closed system pharmaceutical preparation adapters.

Methods Commonly prepared Tc-99m radiopharmaceutical kits were prepared outside of an ISO 5 compounding environment using closed system adapter components. For each product, six radiopharmaceutical kits were prepared using a vial compounding adapter (approximately 5-10 mCi in 10 ml total volume). After radiolabeling, 3 x 1 ml sterility samples were removed using the syringe adapter. Samples from 3 of the kits were used to inoculate trypticase soy broth (TSB) and samples from the remaining 3 kits were used to inoculate fluid thioglycollate (FTG) sterility media, in order to evaluate sterility of the products during the compounding process. Next, 9 x 0.6 ml samples of each radiopharmaceutical kit prepared were withdrawn into 3ml syringes for post dispensing stability testing (3 syringes for each time point: T = 0, 12 and 24 hours) to evaluate for product degradation over time as a result of the adapter system. Stability testing was performed using commonly recognized ITLC chromatography test standards. After preparation and dispensing were completed, a wipe test was performed of the external components of the adaptor system and analyzed using a single channel scintillation detector to evaluate for the presence of radioactive spills from the adaptor. At 24 hours, the residual activity in the vial was removed and additional sterility testing was performed to determine if the adapter system allowed for the introduction of any contaminants during the dispensing process. At the conclusion of the 24 hour testing period, the adapter system was removed and evaluated for retained activity in the adapter itself. All tests were repeated on the same number of control samples prepared and dispensed without the adapter system.

Results Preliminary results show that the closed system adaptor provided sufficient sterility results to verify its ability to allow for sterile product compounding outside of an ISO 5 compounding area. From a stability standpoint, in general, the use of the closed system adaptor did not significantly change the quality of most of the radiopharmaceuticals prepared. There were some potential barriers to widespread use that were identified as part of the testing process.

Conclusions The role of a closed system adapter in the preparation and dispensing of Tc-99m labeled radiopharmaceuticals has exhibited some potential benefits, although there are some possible