RESUMO
Labelling yield and radiochemical purity, higher than 95%, of 99mTc-colloid preparations were determined by using the paper chromatography method. Less than 3% of labelled citric acid, added to the preparation as a buffer solution, has been found in 99mTc-sulphur colloid. High radiochemical purity and optimum size of colloid particles has also been proved by biodistribution studies on experimental animals. The analysis performed has shown that more than 50% of 99mTc-colloid preparations excreted by urine is 99mTcO-, the remaining past 50% being protein bound 99mTc. Biological half-time of excretion of the fast phase is the same for both preparations, i.e. 10 min, while for the slow component it is 120 min in 99mTc-S-colloid and 160 min in 99mTc-Sn colloid.
Assuntos
Kit de Reagentes para Diagnóstico/normas , Enxofre/normas , Compostos de Tecnécio , Tecnécio/normas , Compostos de Estanho , Estanho/normas , Animais , Meia-Vida , Cinética , Ratos , Enxofre/metabolismo , Tecnécio/metabolismo , Coloide de Enxofre Marcado com Tecnécio Tc 99m , Estanho/metabolismo , Distribuição Tecidual , IugosláviaRESUMO
Several chromatographic methods have been used for determining the radiochemical purity of 99m Tc-diethyl HIDA (Solco HIDA). Good separation of 99mTc-HIDA from 99mTc-hydrolyzate and nonreduced 99mTcO4- was obtained in a short time using Gelman ITLC (SA) and 2N NaC1 as the mobile phase. In vitro stability was followed by the same method. It was found that the presence of oxygen from air enhances the percentage of 99mTcO4- in the preparation. Formation of a chelate of 99mTc-HIDA with a high stability constant was established by using Sephadex G-25 filtration. The degree of binding of 99mTc-diethyl HIDA to blood plasma proteins, examined by the same method. In vivo stability was examined by analyzing bile and urine, which were found to contain 99mTc-HIDA chelate. Biodistribution of the preparation was also investigated in experimental animals.
