储存在注射器中的（99m）Tc-ECD和稳定化（99m）Tc-HMPAO的稳定性评估。

Koslowsky I L, Brake S E, Bitner S J

Nuclear Medicine, Foothills Medical Centre, Calgary, Alberta, Canada.

J Nucl Med Technol. 2001 Dec;29(4):197-200.

OBJECTIVE

To determine and compare the stability of (99m)Tc-ECD and stabilized (99m)Tc-HMPAO when stored in syringes over an 8-h period.

METHODS

(99m)Tc-ECD and stabilized (99m)Tc-HMPAO were prepared according to the manufacturers' protocols, with the following exception: eluate less than 60 min old was used to prepare (99m)Tc-HMPAO rather than the recommended 30 min. Once prepared, 185 MBq (5 mCi) of both products were drawn into 5-mL syringes and allowed to sit at room temperature. At 2, 4, 6, and 8 h after preparation, the radiochemical purity (RCP) of the contents of the syringes was determined and compared to the RCP of the products in vials. Retention of activity of each product in syringes was also evaluated by measuring activity remaining in each syringe (and filter, in the case of (99m)Tc-HMPAO) after expressing its contents.

RESULTS

The RCP of stabilized (99m)Tc-HMPAO stored in syringes decreased from a mean of 87.7% at 2 h to 74.0% at 8 h after preparation. In contrast, (99m)Tc-ECD retained an RCP of greater than 94% throughout the time tested. The impurity that appeared to increase over time with (99m)Tc-HMPAO was found to be sodium pertechnetate. Total retention of activity remaining in the syringe and filter ranged from 11.6% at 2 h to 9.5% at 8 h for (99m)Tc-HMPAO; the syringe itself retained less than 5% of the total activity at all time periods. (99m)Tc-ECD exhibited 6.2% to 11.3% retention of activity in the syringe. The sorption of sodium pertechnetate to the syringe for the same time period was less than 1%.

CONCLUSIONS

(99m)Tc-ECD is a more stable product than stabilized (99m)Tc-HMPAO in a syringe. Both products demonstrate retention of radioactivity in the syringe. Some of this retention may denote sorption of the products to plastic.

目的

测定并比较（99m）Tc - ECD和稳定化（99m）Tc - HMPAO在注射器中储存8小时期间的稳定性。

方法

按照制造商的方案制备（99m）Tc - ECD和稳定化（99m）Tc - HMPAO，但有以下例外：使用制备时间小于60分钟而非推荐的30分钟的洗脱液来制备（99m）Tc - HMPAO。制备完成后，将两种产品各185 MBq（5 mCi）吸入5毫升注射器中，并置于室温下。在制备后2、4、6和8小时，测定注射器内内容物的放射化学纯度（RCP），并与小瓶中产品的RCP进行比较。还通过测量每种产品在注射器（对于（99m）Tc - HMPAO，还包括过滤器）内的内容物挤出后剩余的活性，来评估每种产品在注射器中的活性保留情况。

结果

储存在注射器中的稳定化（99m）Tc - HMPAO的RCP在制备后2小时时平均为87.7%，到8小时时降至74.0%。相比之下，（99m）Tc - ECD在整个测试期间的RCP保持在94%以上。发现随着时间推移，（99m）Tc - HMPAO中似乎增加的杂质是高锝酸钠。对于（99m）Tc - HMPAO，注射器和过滤器中剩余活性的总保留率在2小时时为11.6%，到8小时时为9.5%；在所有时间段，注射器本身保留的总活性不到5%。（99m）Tc - ECD在注射器中的活性保留率为6.2%至11.3%。在相同时间段内，高锝酸钠对注射器的吸附率小于1%。