Search Results
Abstract
The synthesis of a complex molecule with its coordination center composed by a triamide monomercaptide tetradentate set of donor groups plus a phenyl-acetyl group as protector group of a sulphur atom is reported. This compound has been mixed with immune glubulin G, labeled with 99mTc and purified by high resolution liquid chromathography (HRLC). The biological behavior of this labeled compound was evaluated with mice of Balb-C origin, showing the biological properties of a protein. This molecule might be another option for radio-immuno-scintigraphic analysis when using proteins of antigenic nature.
Summary
The lyophilized MIBI kit was dissolved in 1 ml sterile saline or 250mg/ml ascorbic acid and dispensed into 0.2 ml fractions, which were stored at -20 °C for 12 days. The solution was prepared by using two different protection methods. In the first method evacuated vials were used for storage of fractionated solution while in the second method an antioxidant agent, ascorbic acid was employed. The radiochemical impurity of 99mTc-MIBI in the unprotected fractions rises with time. Exclusion of air as well addition of ascorbic acid in fractionated solutions gave very good results. The labeling efficiency and biodistribution of fractionated solutions was the same as the lyophilized kit even after 12 days.
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 based on the sorption of99mTc in MEK on an acid alumina column has been investigated. A number of parameters as column dimension, amount of alumina, MEK volumes, etc. is found to affect the extent of adsorption and the final purity of99mTc solution. These parameters have been standardized and a method for rapid recovery of MEK-extracted99mTc has been developed. The final characteristics of the99mTc is found to conform to pharmacopoeia specification.
Abstract
A method is discussed for separating99mTc from99Mo by dissolution and reprecipitation of CaMoO4 containing99Mo-99mTc.99mTc can be obtained successfully with a yield of about 80% and with a radionuclidic purity as high as over 99.7%. On the other hand, by agitating Ca99 MoO4 solid with 0.9% NaCl aqueous solution,99mTc can directly be obtained with a yield of about 30% without any impurities.
Abstract
The preparation of99mTc-Sn-DOTA,99mTc-Sn-DDDTA and99mTc-Sn-DHDTA is described. The labelling efficiency of all samples was checked by paper chromatography, thin layer chromatography and paper electrophoresis. Preliminary results of the biodistribution studies performed in white rats are given.
Abstract
Solvent extraction separation of99mTc from99Mo using methyl ethyl ketone(MEK) has been found to be an effective method of obtaining99mTc of medicinal purity from low specific activity99Mo. The authors have investigated the effect of alkali and molybdenum concentration on the extraction of99Mo and99mTc into methyl ethyl ketone. The possibility of methyl ethyl ketone forming enol and condensation products and its effect on the final extraction efficiency and purity of99mTc has been studied. Sodium molybdate has been found to have a good salting out effect on99mTc pertechnetate and hence99mTc extraction can be better accomplished from low specific activity99Mo solutions. The ketone seems to form traces of condensation products in the extraction procedure. These have been found to be coextracted with99mTc into MEK but did not affect the extractability of99mTc. It was observed that neutral alumina column removes these condensation products from MEK containing99mTc. Alternately these could be filtered off by acidification of the final aqueous99mTc solution. The studies indicate that under optimum experimental conditions methyl ethyl ketone separates99mTc from99Mo with high efficiency and yields99mTc of high purity suitable for use in nuclear medicine in the form of various labelled compounds.
Abstract
The comparative pharmacokinetic study of PAHIDA-99mTc p-(biscarboxymethyl)-aminomethylcarbaminohipuric acid, MAG3-99mTc (mercaptoacetyltrigly cine) and DTPA-99mTc (diethylenetriaminepentaacetate) was made by measurement of biodistribution, blood clearance, volume distribution, half-lives of distribution and elimination, and other relevant parameters. The percentage of protein binding was determined too, by the methods of dialysis and precipitation. These results were used to calculated the constants and rates of protein binding. The results of biodistribution show that MAG3-99mTc exibits a higher in the same time interval. The present work also reports results of clinical investigation of PAHIDA-99mTc.
Abstract
Large columns containing aluminum oxide (Al2O3) or gel (e.g. zirconium molybdate) are needed to prepare 98Mo(n,γ)99Mo→99mTc column chromatographic generators that results in large elution volumes containing relatively high 99Mo impurity and low concentrations of 99mTc. The decrease in radioactive concentration or specific volume concentration of 99mTc places a limitation on some pharmaceutical kits (DTPA, MIBI, ECD, etc.) or clinical procedures. We report on the post elution concentration of 99mTc using in house prepared lead cation-exchange and alumina columns. Using these columns high bolus volumes (10–60 mL 0.02M sodium sulfate) of 99mTc can conveniently be concentrated in 1 mL of physiological saline. This approach also works very effectively to prepare high specific volume solutions of 99mTc-pertechnetate from a fission based 99Mo/99mTc generator in the second week of its normal working life.
Abstract
Evidence is obtained to show that the liquidliquid extraction separation of99mTc from99Mo with methyl ethyl ketone, methyl propyl ketone and methyl isobutyl ketone can be transformed into a solid-phase column extraction procedure. The aqueous alkaline99molybdate solution is immobilized on a column of a granular large-pore diatomaceous earch support, which is the neluted with the abovementioned extractants. Rapid and clean separation of99mTc can be with all three solvents. The99mTc can be back-extracted from the organic phase on a column filled with distilled water /or saline/ loaded granular diatomaceous earth /Extrelut®/. The possibility of using the abovementioned procedure as a basis for a new99mTc/99Mo generator concept is envisaged.
