Abstract
PHOTOFRIN (R) was labelled with Tc-99m using SnCl2 2H(2)O as reducing agent Instant thin layer chromatography (ITLC-SG) in 0 05 M NaOH was used for evaluation of radiochemical purity Labelling efficiency was dependent on various factors that include the ligand/reductant ratio, pH and time of incubation Therefore optimum conditions of labelling were also determined The stability of Tc-99m-PHOTOFRIN (R) in serum was checked by using fresh human serum Tissue distribution of Tc-99m-PHOTOFRIN (R) was evaluated in Sprague Dawley rats
PHOTOFRIN (R) was labelled with an efficiency of > 95% under optimum conditions, which were PHOTOFRIN (R) 200 mu g, pH 3-4 SnCl2 2H(2)O 15 mu g and 30 mm incubation at room temperature The Tc-99m-labelled PHOTOFRIN remained stable in human serum for 24 h Biodistribution study in rats revealed maximum concentration of the labelled compound in liver, lungs and spleen at 0 5 h, and significant activity as also seen in the bladder and urine, indicating the mode of urinary excretion of PHOTOFRIN (R)