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- Author or Editor: N. Agha x
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Abstract
A formulation of stannous-diethyl-IDA freeze-dried kit, containing 50 mg diethyl-IDA and 0.4 mg hydrated stannous chloride, to be labelled with technetium has been developed for hepatobiliary scintigraphy. Gel chromatography column scanning technique has been applied for determination of technetium fractions in the preapration. The optimal pH value of the preparation with a high hepatobiliary specificity was found between 5.5 to 6.0. Effect of ligand to metal ratio on the stability of the prepared Sn-diethyl-IDA solution prior mixing with technetium has been investigated. The reaction conditions (initial pH) between the ligand and stannous ion affects the percent hydrolysis of the labelled compund, i.e. the formation rate of the complex. The organ distribution data of99mTc-diethyl-IDA in mice for 60 minutes post injection were satisfactory. The radiopharmaceutical exhibits rapid blood clearance, great hepatic clearance and very short hepatocyte transit time. Uptake of the radiopharmaceutical in various organs of mouse at 5 minute post injection showed that the greater part of the injected radioactivity has distributed between liver and intestine. However, about 12% and 60% of the injected dose has been found in liver and intestine respectively. The renal uptake of the HB agent in mice is relatively low and decreases with time to become about 0.3% at 60 minutes post injection. Blood clearance data of the radiopharmaceutical kit in rabbits showed that the HB agent is-rapidly cleared, since the initial decrease was very fast with a half-time of 1.5 minutes.
Abstract
The available six types of Sephadex and one type of Sepharose have been applied in the separation of technetium fractions in99mTc-labelled radiopharmaceuticals produced in our laboratory using the GCS technique. By this technique the chemical state and the percentage of99mTc-fractions have been determined. The resolution efficiency of some gel types were found to be significantly influenced by the pH of the eluent. The results obtained from the experiments indicated that Sephadex G-25 Fine was the best and can be routinely used in the radiochemical analysis of the following kits:99mTc-HSA,99mTc-DTPA and99mTc-HIDA and G-100 for99mTc-PYP. With99mTc-HSA and99mTc-PYP kits, 0.9% NaCl eluents at pH 3.2 and pH 2 to 2.5, respectively, were found to be necessary for the separation of99mTc-fractions. G-50 Fine was found to be the best gel between the others in the separation of99mTc-fractions in testing of the weak radiopharmaceuticals,99mTc-GH and99mTc-MDP. The development of99mTc-MDP with the eluent at the same pH as the preparation gives negligible interaction effect.
Abstract
A method for preparing99mTc-citrate complex, using instantly formed cuprous ions for the reduction of pertechnetate is described. The labelling kinetics, formation rate and stability of99mTc-Cu-citrate complex were studied. Gel filtration using column scanning technique has been found to be a reliable and unique tool for determining the amount of99mTc-fractions as a function of time in the preparation. The kidney uptake and excretion characteristics suggest a potential usefulness of99mTc-Cu-citrate complex for renal function studies. The safety measures for the amount of the complex to be injected in man have been estimated.
Abstract
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 with99mTc, 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 of99mTc-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 of99mTc-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 of99mTc-Dx.
Abstract
The formulation of a freeze-dried sulphide colloid kit, to be directly labelled with technetium is based on the preparation of tin/II/ sulphide precolloid, stabilized with carboxy methyl cellulose. The formation kinetics of the labelled colloid assessed by GCS-method showing a fast reduction of99mTc-pertechnetate, forming reduced99mTc-colloid with subsequent build-up of the labelled sulphur colloid. This is assumed to be due to the formation of99mTc/V/ to be bound to sulphide precolloid of the kit. The blood clearance data of the labelled colloid in rabbits showed two exponential disappearance phases of radioactivity from blood with biological half times of 3 and 67 min. The results of organ distribution in mice show that more than 85% of the administered activity is accumulated in the liver indicating a high colloidal yield of optimal particle size. The dynamic studies of the labelled colloid achieved in normal subjects using gamma camera indicate a rapid blood clearance and high liver uptake with low surrounding tissue background.
