Stability in vitro

lipophility and acute toxicity of p-Boc-Trp-Trp-NH(CH2)6NH-PO (ONH4)-O-Ph131I are studied in this work.The complex

with labeling yield of around 85%

was obtained using sealed-tube method.Stability of the complex was obtained by measuring labeling yield at different time.Its lipophility was studied through swaging-flask method

and its impacts to liver function and peripheral blood of the experimental animals were also studied.The results indicate the complex is lipophilic and less toxic

and the iodine removal rate was about 13% three days later.The rabbit model with VX2 liver tumor was established successfully.The organ and tissue uptake and retention of p-Boc-Trp-Trp-NH(CH2)6NH-PO(ONH4)-O-Ph131I were studied in a model subject.Blood

liver

lungs

kidneys

spleen and tumour tissue samples were assayed in a well counter for radioactivity and the results were compared with the biodistribution studies in five normal mice.The complex trends to concentrate into adipose tissues in tumour-bearing and normal animals

and the uptake rate in tumor tissue is relatively high

hence its potential possibility as radiopharmaceuticals.But it cleared quickly.Further researches are underway to improve the stability of complexes to prolong concentration time in target tissue.