Ivancević V, Kuster Z, Mastrović Z, Ivancević D
Department of Nuclear Medicine, University Hospital Rebro, Zagreb, Yugoslavia.
Eur J Nucl Med. 1990;17(1-2):34-7. doi: 10.1007/BF00819401.
The radiochemical purity of hexamethylproxypropylene amine oxime (HMPAO) was determined in 16 preparations using the three-strip method. Immediately post-formulation, 90.3% +/- 4.0% (mean +/- SD) of the activity was associated with the primary lipophilic complex having an Rf of 0.45 +/- 0.11. We recorded a significantly higher content of sodium pertechnetate Tc 99m in methylethyl ketone (MEK) (21.1% +/- 8.5%) than in saline (5.0% +/- 3.7%; P less than 0.001). To clarify this finding, we ran sequential chromatograms (t = 0, 1, 2, 3 h) and found that the primary complex steadily disappeared, with a rate constant of 0.31 h-1. These results suggest that there is a decomposition of the primary complex during chromatography in MEK that might be responsible for the larger fraction of sodium pertechnetate Tc 99m in MEK. Eluate composition might influence the Rf of the lipophilic complex and the rate of its in vitro decomposition. In another experimental setting, we investigated 99mTc-HMPAO decomposition species in urine after application of a suspension of labelled leukocytes by performing sequential chromatographic analyses in 11 patients. At 1 h after application, urinary activity reflected the presence of a secondary complex (84.8% +/- 9.2%) and sodium pertechnetate Tc 99m (15.2% +/- 9.2%). The values after 3 h were markedly different (91.4% +/- 4.8% and 8.6% +/- 4.8%; P less than 0.001). Thus, urinary activity mostly consisted of a secondary complex, increasing with time.
采用三条带法对16份制剂中的六甲基丙烯胺肟（HMPAO）放射化学纯度进行了测定。制剂刚制备完成后，90.3%±4.0%（均值±标准差）的活性与Rf为0.45±0.11的主要亲脂性复合物相关。我们记录到，甲基乙基酮（MEK）中高锝酸钠Tc 99m的含量（21.1%±8.5%）显著高于生理盐水中的含量（5.0%±3.7%；P<0.001）。为阐明这一发现，我们连续进行了色谱分析（时间点为0、1、2、3小时），发现主要复合物逐渐消失，消失速率常数为0.31 h⁻¹。这些结果表明，在MEK中进行色谱分析期间，主要复合物发生了分解，这可能是MEK中高锝酸钠Tc 99m比例较高的原因。洗脱液成分可能会影响亲脂性复合物的Rf及其体外分解速率。在另一个实验环境中，我们通过对11名患者进行连续色谱分析，研究了注射标记白细胞悬液后尿液中99mTc-HMPAO的分解产物。注射后1小时，尿液活性反映出存在一种次要复合物（84.8%±9.2%）和高锝酸钠Tc 99m（15.2%±9.2%）。3小时后的数值有显著差异（91.4%±4.8%和8.6%±4.8%；P<0.001）。因此，尿液活性主要由一种次要复合物组成，并随时间增加。
