Preparation and biological evaluation of Tc99m-Sn phosphate colloid for the study of reticuloendothelial system

ABSTRACT

A colloid of sodium dihydrogen phosphate and stannous chloride was prepared at pH 6.0 which could be instantly labellea with Tc [99m]. Labelling yield was over 96% as determined by paper chromatography, ultrafiltration and gel chromatography. Effect of heat, pH, electolytes and concentration on the stability of the colloid was studied by visual inspection. Particle size of the colloid was adjusted by observing agglomeration and comparing with other colloids like Tc [99m] Tin and Tc [99m] Sulphur. Biodistribution study performed in mice showed 70% of the colloid uptake in liver, 4% in spleen and 7% in bone marrow at one hour post-injection of Tc [99m]-Sn-PO4 colloid. Time-activity curve drawn showed maximum uptake in the liver area at 15 minutes post-injection. The radiocolloid showed a potential in the study of liver malfunctions in humans. No lung uptake was detected and no sign of toxicity was observed