@article {del Carmen Plancha-Mansanet213, author = {Maria del Carmen Plancha-Mansanet and Elisa Caballero-Calabuig and Jes{\'u}s F{\'e}lix-Fontestad and Mar{\'\i}a Dolores Reyes-Ojeda and Pablo Sopena-Novales and Pedro Abreu-S{\'a}nchez and Maria del Carmen Cano-Terol and Ram{\'o}n Sopena-Monforte}, title = {Stability of Stabilized 99mTc-d,l-HMPAO Stored in Vials and Syringes}, volume = {36}, number = {4}, pages = {213--216}, year = {2008}, doi = {10.2967/jnmt.108.053488}, publisher = {Society of Nuclear Medicine}, abstract = {Our objective was to determine the stability of stabilized 99mTc-hexamethylpropylene amine oxime (99mTc-d,l-HMPAO) dispensed by vial and syringe, with the storage time and labeling activity varied. Methods: 99mTc-d,l-HMPAO was labeled according to the manufacturer{\textquoteright}s instructions, but with modification of the 99mTcO4Na activity. Two groups were prepared: 1,110 MBq (30 mCi) and 2,600{\textendash}3,700 MBq (70.3{\textendash}100 mCi). Five minutes after labeling, the radiochemical purity (RCP) of the vial content was determined. Afterward, the same activity was distributed into two 2-mL syringes and into the manufacturer{\textquoteright}s vial. In one of the syringes, the radiopharmaceutical stayed in contact with the needle for 4 h. At 2 and 4 h after labeling, the RCP of the vial and syringe content was checked and compared. Results: The mean RCP of stabilized 99mTc-d,l-HMPAO labeled with 1,110 MBq (30 mCi) and stored in a vial decreased from 93.1\% at 5 min to 92.1\% at 2 h and to 91.1\% at 4 h. With storage in a syringe, the RCP decreased from 89.8\% at 2 h to 88.7\% at 4 h. This diminution increased for labeling with higher activities (2,600{\textendash}3,700 MBq [70.3{\textendash}100 mCi]), ranging from 91.4\% at 5 min, 89.0\% at 2 h, and 85.3\% at 4 h in a vial and from 85.9\% at 2 h to 80.2\% in a syringe. 99mTcO2 and secondary 99mTc-HMPAO were the main impurities at t = 0. 99mTcO4- was an impurity that increased with time in both vials and syringes but significantly so in syringes. All these impurities were higher with labeling activities in the range of 2,600{\textendash}3,700 MBq (70.3{\textendash}100 mCi). Contact of the needle with 99mTc-d,l-HMPAO sharply decreased the RCP to 57.1\% at 4 h. Conclusion: The RCP of stabilized 99mTc-d,l-HMPAO decreases significantly in both vials and syringes with high labeling activities. The product is less stable when stored in a syringe than in a vial. The fraction of dose in contact with the needle affects the RCP results.}, issn = {0091-4916}, URL = {https://tech.snmjournals.org/content/36/4/213}, eprint = {https://tech.snmjournals.org/content/36/4/213.full.pdf}, journal = {Journal of Nuclear Medicine Technology} }