Biodistribution in rats of 99Tcm-labelled human serum albumin

Three different 99Tcm-human serum albumin (HSA) preparations were simultaneously studied by high pressure liquid chromatography (HPLC) and gamma camera techniques in rats. The products contained variable amounts of 99Tcm-human albumin, 99Tcm-tin colloid and a 99Tcm-low molecular weight complex. The biological half life varied from 55 to 132 min and the bladder excretion for the first 60 min from 2 to 31%. Separated HPLC fractions of 99Tcm-albumin and 99Tcm-tin colloid both showed considerably longer biological half life when injected separately than when injected in the unfractionated preparation. A final evaluation of the quality of such products seem to require evaluation in humans.