Influence of magnetic field on the reduction of 4,8-diaza-3,6,6,9-tetramethyl undecane-3,8-diene2,10-dione dioxime

The influence of the magnetic field with the magnetic induction up to 1,35T on the reduction of 4,8-diaza-3,6,6,9-tetramethylundecane-3,8-diene-2,10-dione dioxime (DI) in anhydrous protic solvents (anhydrous ethanol and 2-propanol) was defined. As the reductants NaBH4 and KBH4 were usedPhysical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Evalaution of radioiodination of synthesised meta-iodobenzylguanidine catalyzed by in situ generated Cu(i)

Meta-iodobenzylguanidine (m-IBG) is a biogenic amine precursor, noradrenaline analogue, which is actively taken up by tumors. In tracer amounts, [123/131I]-m-IBG is used as a radiopharmaceutical to target normal and malignant tissues of neuroadrenergic origin for diagnostic scintigraphy, and labeled with higher activities of 131I, it is used for therapy of phenochromocytoma and neuroblastoma. The increased clinical therapeutic use of unlabeled m-IBG at doses of up to 40 mg/m2 emphasizes the need for syntheses and an established quality protocol for this substance that relies on verifiable analytical parameters. Evaluation of radioiodination was necessary to obtain higher labeling yield (we achieved over 90% instead no more than 70%), because isotopic exchange labeling of m-IBG with 131I catalyzed by Cu(I) is much more efficient than with conveniently used ammonium sulphate.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Electrochemical separation of 90-yttrium in the electrochemical 90Sr/90Y generator and its use for radiolabelling of DOTA-conjugated somatostatin analog [DOTA0, Tyr3] octreotate

Radiopharmaceuticals based on 90Y are widely used in the treatment of malignant deseases. In order to meet the requirements for their future application, a 90Sr/90Y generator was developed and 90Y eluted from this locally produced generator was used for the radiolabelling of the DOTA-conjugated somatostatin analog [DOTA0,Tyr3] octreotate and the preparation of [90Y-DOTA0,Tyr3] octreotate (90Y-DOTATATE) for peptide receptore radionuclide therapy. 90Sr/90Y generator was based on the electrochemical separation of 90Y from 90Sr in a two-cycle electrolysis procedure. Three electrode cells were used to perform both electrolyses. In both cycles, working electrodes were kept on constant potential. The pH of the solution was adjusted to 2.7 of the value before the electrolyses. The radionuclidic purity of the 90Y solution was analysed by ITLC and extraction paper chromatography. The labelling of peptide (100 mg DOTATATE) with 90YCl3 was performed at 95°C for 30 minutes. Radiochemical purity was determined by HPLC and chromatographic separation, using a solid SepPak C-18 column. Results obtained confirmed the efficiency of our electrochemical separation technique and quality control methods for 90Y. The achieved efficiency of the 90Sr/90Y generator above 96% of the theoretical value represents a good basis for the further development of this generator. The labelling of the DOTATATE with 90Y exhibited a high efficiency, too: there was less than 1% of 90Y3+in the 90Y-DOTATATE

Technetium-99m in Production and Use

Several types of generators have been developed for the production of (99m)Tc. Due to its excelent performances, the chromatographic type, based on the fission-produced (99)Mo sorbed in alumina, is predominant. Technetium-99m is obtained in the form of sodium pertechnetate-(99m)Tc. However, due to the known disadvantages of the production of (n, f)(99)Mo, attempts are made to avoid uranium fission. The technologies based on (n, gamma)(99)Mo (sublimation, extraction, gel) are, with the exception of the gel generator, of limited importance. Certain nuclear reactions in cyclotrons can produce (99)Mo (or directly (99m)Tc) but the obtained results are still not satisfying. Technetium-99m is used in the form of radiopharmaceuticals which are prepared by addition of (99m)Tc-eluate to the inactive components comprised in the cold kits. The chromatographic (n, f)(99)Mo/(99m)Tc generator and several (99m)Tc-radiopharmaceuticals have been developed and are regularly produced in the Vinca Institute of Nuclear Sciences (Laboratory for Radioisotopes)

Synthesis and characterization of a new diaminodioxime, a potential ligand for 99mTc radiopharmaceuticals

This paper reports synthesis of a new diaminodioxime ligand, derivative of hexamethylpropyleneamine oxime (HM-PAO). The 99mTc(V)-d,l-HM-PAO complex is well-known radiopharmaceutical for regional blood flow imaging. The structure of the new ligand was investigated by elemental analysis, IR, 1H and 13C NMR. Complexation studies with 99mTc were carried out using stannous chloride as the reducing agent. The complex was characterized by paper chromatography and thin-layer chromatography. It was obtained in high yield when the reactions were carried out at pH=9. Also, it was found that the complex was stable up to 4 h

Application of ascorbic acid as a radiolytic stabilizer for [131I]mibg

In this paper the results of a stability of [131I]mIBG, stored under various conditions, are presented. The stability was followed during 14 days. The most important radiochemical impurity in [131I]mIBG is free [131I]iodide, formed by radiolysis. The results indicate that the rate of radiolytic decomposition of [131I]mIBG is much slower at higher concentration of ascorbic acid (20 mg/mCi) and at lower storage temperature (40C)

Synthesis and characterization of a new diiminedioxime ligand and its copper (ii) complex as potential 64Cu(ii)-radiopharmaceuticals

As a part of effort to an develop 64Cu-based radiopharmaceuticals for PET (positron emission tomography) imaging of multidrug resistance in cancer, a new diiminedioxime ligand was prepared. Its Cu(II) complex was synthesized from Cu(OAc)2 by heating in methanol. The structure of the ligand was established using elemental analysis, UV-Vis, IR, 1H and 13C NMR technique. The isolated complex was characterized by means of elemental analysis, IR and UV-Vis, and its structure was proposed

Physicochemical evaluation of Technetium-99m complexes with baclofen

The 99mTc-labeling of baclofen (Bac), a muscle relaxant, as well as physicochemical properties of the labeled compounds are investigated. Two different approaches for the labeling with 99mTc have been studied: direct reduction with tin(II)chloride and the 'organometallic approach' using [99mTc(CO)3(H2O)3] + precursor. The direct labeling approach was not successful and the yield was poor. The use of [99mTc(CO)3(H2O)3]+ precursor pointed at the formation of 99mTc(I) coordinated complexes with high yield. In this approach, pH didn’t influence the yields. Promising results of in vitro experiments suggest that 99mTc(I)-baclofen may be of potential use for diagnosis of some central nervous system disorders.Physical chemistry 2012 : 11th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 201

99mTc-complex of novel diamine-dioxime ligand

Novel diamine-dioxime ligand, 4,7-diaza-3,8-diethyldecane-2,9-dione bis oxime (LH2), derivative of hexamethyl-propylene amine oxime (HMPAO), was synthesized in order to develop new brain perfusion imaging agent, based on 99mTc(V) complexes. The 99mTc(V)-d,l-HMPAO complex is well-known radiopharmaceutical for brain imaging. The structures of the synthesized compound were characterized by UV-Vis, IR, 1 H NMR and 13C NMR. The procedure for radiolabeling of diamine-dioxime with 99mTc was developed and radiolabeling yield of the 99mTc-complex was followed by paper and thin-layer chromatography. The maximum radiolabeling yield was obtained when the reactions were carried out at pH~9 within 10 min at room temperature (RT). Biodistribution studies on rats has shown significant uptake of 99mTc-complex (2.1% ID), 2 min after injection.Physical chemistry 2012 : 11th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 201

Preparation of 90Y-Labeled Tin Fluoride Colloid for Radiosynovectomy

In this study, tin fluoride colloid (SnF-c) was prepared, labeled with 90Y and characterized with respect to its physicochemical properties. Particle size of SnF-c, at constant concentration of SnF2, was dependent on pH, concentration of NaF, temperature and time. The particle size of SnF-c decreased with an increase in NaF concentration and a decrease in reaction mixture pH. Radiolabeling yield of 90Y-SnF-c at higher temperature increased and it was greater than 98% for the preparation at 95 oC. Due to high labeling yield and stability, 90Y-SnF-c might be a promising agent for radiosynovectomy.Physical chemistry 2012 : 11th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 201