Technetium-99m dextran kit: formulation and biological behaviour

A new formulation of stannous-dextran (Sn-Dx) freeze dried kit, containing 60 mg dextran (Dx-70) and 0.08 mg SnCl₂·2H₂O, to be labelled with^99mTc, has been developed. At pH 6.5–7.0. the labelling efficiency was greater than 95%. Gel chromatography column scanning technique was applied for radiochemical purity determination of^99mTc-Dx preparation and the degree of in vivo plasma protein binding. Not less than 70% of the administered activity was bound to plasma and remained constant over a 1h period. The biological behaviour after intravenous injection of^99mTc-Dx kit was characterized by high and efficient yield of the radiopharmaceutical. The preliminarly clinical results on normal subjects showed that the radiopharmaceutical could be a useful agent for scintigraphy of leg lymph vesel, pelvic and inguinal lymph nodes. The activity uptake in liver and kidney (60 min) was relatively very low, whereas the urinal bladder activity (30 min) represents the drainage of the activity entering the blood stream after interdigital injection of^99mTc-Dx.