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The behavior of 153Sm-EDTMP in vitro and vivo is analyzed by the size exclusion HPLC. The experimental results show that EDTMP amounts have an obvious effect on the stability in vitro and uptake of 153Sm-EDTMP in the liver. HPLC analysis of urine sample indicates that 153Sm-EDTMP is excreted in the original form. The behavior in vivo of 153Sm-EDTMP containing 4 ~tg is similar to that of 153Sm-EDTMP containing 50 ~tg EDTMP at 1 h post-injection.1

Radiolabeled somatostatin analogue is a useful ligand for scintigraphic imaging of somatostatin receptor-bearing tumors. In this study, we investigated the effects of different radiolabeling conditions on labeling yield and ratio between mono-iodinated and di-iodinated 125I Tyl 3-octreotide by HPLC analysis. In vitro and in vivo stabilities of 125I Tyr3-octreotide and 11 lin_DTPA_D_Phel_octreotid e were also determined. Both radiolabeled compounds were relatively stable in vitro, but were decomposed to free 125I and 11 lin_DTP A in vivo, respectively.

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DTPA-Octreotide(Pentetreotide), a somatostatin analogue which can bind specifically and with high affinity to somatostatin receptor in vitro and vivo, labeled with 99mTc by tin reduction in acetate buffer, has been characterized by Reverse-phase High performance Liquid Chromatography. The effect of different solvents, mobile phase pH, linear gradient and the injected volume on the separation efficiency was evaluated. The results show that the separation efficiency is best using ~tBondapak-C18 (300x3.9 mm2), linear gradient of 40% to 80% methanol (1.0 ml/min) in 0.05M acetate buffer (pH 5.5) over a 30 min period and maintaining for another 10 min. The labeled product is a mixture which mainly consists of five components (a, b, c, d, e) successfully proved by HPLC. Paper chromatography is also evaluated in this paper. It may be used to determine the radiochemical purity of the labeling product, but is not a good choice for the verification each components.