TY - JOUR T1 - Stability of Stabilized <sup>99m</sup>Tc-<span class="sc">d</span>,<span class="sc">l</span>-HMPAO Stored in Vials and Syringes JF - Journal of Nuclear Medicine Technology JO - J. Nucl. Med. Technol. SP - 213 LP - 216 DO - 10.2967/jnmt.108.053488 VL - 36 IS - 4 AU - Maria del Carmen Plancha-Mansanet AU - Elisa Caballero-Calabuig AU - Jesús Félix-Fontestad AU - María Dolores Reyes-Ojeda AU - Pablo Sopena-Novales AU - Pedro Abreu-Sánchez AU - Maria del Carmen Cano-Terol AU - Ramón Sopena-Monforte Y1 - 2008/12/01 UR - http://tech.snmjournals.org/content/36/4/213.abstract N2 - 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's instructions, but with modification of the 99mTcO4Na activity. Two groups were prepared: 1,110 MBq (30 mCi) and 2,600–3,700 MBq (70.3–100 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'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 (2,600–3,700 MBq [70.3–100 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 2,600–3,700 MBq (70.3–100 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. ER -