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The radiotracer [99mTc]tricarbonyl Rabeprazole was successfully prepared using the [99mTc]tricarbonyl precursor. The reaction conditions were optimized (200 µg/2 mL substrate concentration, pH 8, incubation temperature 100°C, 30 min) to achieve the maximum radiochemical purity of 98%. Thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) were used to assess the radiochemical purity and quality control parameters. A biodistribution study was also conducted to evaluate the biological biodistribution of [99mTc]tricarbonyl Rabeprazole in three different groups of mice models, with the normal group serving as the control and the second and third groups being microbial and chemically induced stomach ulcer disease models, respectively. The radiotracer [99mTc]tricarbonyl Rabeprazole complex was administered intravenously into mice via the tail vein and dissected at predefined time intervals. The biodistribution data demonstrated that the maximum absorption of [99mTc]tricarbonyl Rabeprazole complex in the stomach of normal mice and microbially and chemically induced ulcerated mice were 9.5, 35.3, and 23.7% ID/g tissue at 1 h post injection, respectively. The outcomes of the research show that [99mTc]tricarbonyl Rabeprazole can be used as a promising imaging agent to diagnose stomach ulcers. [ABSTRACT FROM AUTHOR]

A complex of 99mTc tricarbonyl with Mesalamine for ulcerative colitis imaging was prepared and studied. Several factors such as substrate concentration, pH, reaction period, and reaction temperature were optimized to achieve the highest radiochemical yield and purity. Under optimum conditions, the radiochemical yield of synthesized 99mTc tricarbonyl Mesalamine radiotracer reached 98%. The labeled compound was separated and purified using thin-layer chromatography (TLC) and reversed-phase high-performance liquid chromatography (RP-HPLC). According to biodistribution investigations in a microbial mouse model of ulcerative colitis, the colon localization of 99mTc tricarbonyl Mesalamine was the highest (77.4 ± 1.7%) in 120 min after injection. Thus, 99mTc tricarbonyl Mesalamine can be used as a radiotracer for imaging ulcerative colitis. [ABSTRACT FROM AUTHOR]

Two 99mTc cores, 99mTc tricarbonyl and 99mTc-Sn(II), are compared in labeling of Lansoprazole (Lans). The optimum conditions of Lansoprazole labeling with 99mTc in the presence of SnCl2·2H2O as a reducing agent are as follows: pH 8, 100 μg of SnCl2·2H2O, room temperature, 2 mg of lansoprazole, and 30 min; the maximum radiochemical yield was 98 ± 0.22%. The obtained 99mTc Lansoprazole complex was stable in serum for up to 16 h. The optimum conditions of Lansoprazole binding with the 99mTc tricarbonyl ([99mTc(CO)3(H2O)3]+) core are as follows: pH 8, 2 mg of Lansoprazole, 100°С, 30 min. The complex was stable in serum for up to 12 h. Biodistribution study of the first core on two different groups of mice (control group and ulcer-bearing group) showed comparatively high uptake in the ulcer group of mice, 77.8 ± 1.1% ID/g at 30 min post-injection (higher than for the control group); at 24 h, the uptake decreased to 17.9% ID/g. Similar results were obtained with 99mTc tricarbonyl Lansoprazole: 78.5% ID/g at 30 min post-injection and 24.6% at 24 h. Thus, both complexes are suitable as radiotracers for stomach ulcer imaging. [ABSTRACT FROM AUTHOR]

188Re-5,10,15,20-tetra(4-pyridyl)-21H,23H-porphyrin, [188Re]TMPP, a tumor-targeted agent, was prepared. Under optimum conditions, the 188Re-TMPP yield after purification exceeded 98%. Biodistribution studies showed high tumor uptake of the agent within 30 min post injection (17.5 ± 1.1% ID/g) for Swiss Albino mice bearing Ehrlich ascites carcinoma (EAC). [188Re]TMPP can be considered as a highly selective radiotracer for highly replicating solid tumors. [ABSTRACT FROM AUTHOR]

Aspirin, one of nonsteroidal anti-inflammatory analgesic drugs, was labeled with 125I with a labeling yield of 85.5% under the following conditions: pH 9, 100 mg of the substrate, 50 µg of Chloramine-T, 5–15 min, room temperature. The radiochemical yield of 125I-aspirin was determined by paper chromatography and electrophoresis, and the radiochemical purity was determined by HPLC.125I-aspirin was stable for at least 3 h. Biodistribution of 125I-aspirin in normal and tumor-bearing mice was studied. The uptake of 125I-aspirin in tumor sites makes it promising as a new radiopharmaceutical for tumor imaging. [ABSTRACT FROM AUTHOR]

Three modes of the reaction for labeling of dihydropyridine compounds were studied: thermal heating, microwave irradiation, and solid-state process. [ABSTRACT FROM AUTHOR]

Esomeprazole was labeled with Tc in high (up to ~98.0%) radiochemical yield. The optimum conditions are as follows: pH 8, 50 μg of SnCl·2HO, 30 min, and 2 mg of the substrate. The complex is stable for 8 h. The reaction mixture was separated by gel chromatography using such eluents as NaCl solution and, phosphate, citrate, and carbonate buffer solutions. Free TcO and the complex were also efficiently separated by reversed-phase HPLC, paper chromatography, and electrophoreses. Intravenous biodistribution studies of Tc-esomeprazole complex showed high uptake in the stomach ulcer, reaching about 30.5% ID/g at 1 h post injection. Such a high Tc-esomeprazole uptake makes this agent promising for stomach ulcer imaging. [ABSTRACT FROM AUTHOR]

Rabeprazole, a proton pump inhibitor, was labeled with I to give I-rabeprazole in 98% yield. The optimum conditions were as follows: pH 8, 100 μg of chloramine-T, 30 min, and 0.2 mg of rabeprazole. The labeled compound was stable for 24 h. Biodistribution of I-rabeprazole in mice after intravenous injection was studied, and its high uptake in stomach ulcer, reaching approximately 38% ID/g at 1 h post injection, was demonstrated. This concentration of the labeled compound in stomach ulcer is sufficient for ulcer imaging. The advantages of the method are simple labeling procedure, high labeling yield, and high sensitivity of ulcer imaging. [ABSTRACT FROM AUTHOR]

3-Amino-2-quinoxalinecarbonitrile 1,4-dioxide (QN) was labeled with I, and the biological distribution of the product was studied. I-QN was prepared by direct electrophilic substitution reaction using N-bromosuccinimide (NBS) as an oxidizing agent. The radiochemical yield of 92% was reached under the following optimum conditions: pH 7, 15 min, 100 μg of QN, and 75 μg of NBS. The labeled QN was stable for up to 12 h post labeling. Biodistribution study of I-QN in tumor-bearing mice reflected that it accumulated in tissues with high proliferation rate with preferential accumulation in tumor sites. I-QN was incorporated rapidly in the tumor site (T/NT = 4 at 2 h post injection), and then its content slowly decreased, whereas in the other tissues it decreased rapidly. The results obtained encourage the use of I-QN as a tumor imaging agent. [ABSTRACT FROM AUTHOR]

2-[2-(4-(Dibenzo[ b, f][1,4]thiazepin-11-yl)piperazin-1-yl)ethoxy]ethanol (Quetiapine) labeled with C in 11-position was synthesized in five steps from [carboxy-C]anthranilic acid. The key precursor of the target product is [11-C]dibenzothiazepin-11(10 H)-one. The reaction is performed as one-pot process. [ABSTRACT FROM AUTHOR]

Rabeprazole, antiulcer drug, was labeled with Tc to obtain an agent for ulcer imaging. The radiochemical yield of Tc-rabeprazole reaches approximately 98.5 ± 0.4%.The optimum conditions are as follows: pH 9, 50 μg of SnCl·2HO, 30 min, and 3 mg of the substrate.Tc-rabeprazole was stable for 6 h. Intravenous biodistribution studies of Tc-rabeprazole revealed high concentration in the stomach ulcer, reaching about 33.4% of the total injected dose at 30 min post injection. This concentration of Tc-rabeprazole in stomach ulcer makes this agent promising for stomach ulcer imaging. [ABSTRACT FROM AUTHOR]

Labeling of teicoplanin with Tc using SnCl·2HO as reducing agent was performed. The dependence of the Tc-teicoplanin yield on the concentrations of teicoplanin and reducing agent, pH of the reaction mixture, reaction time, and reaction temperature was studied. Under optimum conditions (2 mg of teicoplanin, 5 μg of SnCl·2HO, pH 9, 30 min, 25°C), the labeling yield of Tc-teicoplanin of 87.7 ± 1.3% was achieved. Tc-teicoplanin is stable for 4 h after labeling; then its relative content decreased gradually to reach 81.7 ± 1.1% in 8 h. Biodistribution studies in mice with infection induced in the left thigh by Staphylococcus aureus were carried out. The bacterial infected thigh/contralateral thigh uptake ratio (T/NT) was evaluated. The time for the maximum accumulation of Tc-teicoplanin in the infection site was 2 h after administration of the labeled compound. The abscess-to-muscle ratio for Tc-teicoplanin was 4.33 ± 0.3, while that for commercially available Tc-ciprofloxacin was 3.8 ± 0.5 under similar conditions. Thus, Tc-teicoplanin can be used for infection imaging. [ABSTRACT FROM AUTHOR]

The Tc-pyrimidine-4,5-diamine (Tc-PyDA) complex was prepared. The yield under the optimum conditions (5 mg of PyDA, pH 8, 25 μg of SnCl·2HO) was 96 ± 3%. The complex is stable in vitro for 24 h. The complex was tested on mice as potential marker for tumor hypoxia imaging. The complex showed high tumor hypoxia uptake with the target/nontarget (T/NT) ratio as high as ∼3. [ABSTRACT FROM AUTHOR]

Sulfadimidine, a bacteriostatic drug blocking folic acid synthesis, was labeled with Tc producing a yield of about 90%. The optimum conditions required to obtain 90% yield of the Tc complex were as follows: 500 μg of sulfadimidine, 100 μg of SnCl·2HO, 5 min, room temperature (25 ± 1°C), pH 4 (0.5 M citrate buffer). The radiochemical purity of the labeled compound was determined using paper and thin-layer chromatography. Biodistribution study in normal mice showed high uptake of the Tc complex in stomach and intestine. The ratio of the uptake of the Tc complex in muscles infected with E. coli to that in normal mice was about 2, 1.5 and 1.4 at 15, 90, and 180 min post injection, respectively, whereas for the muscles inflamed with heat-killed E. coli or sterile turpentine oil the difference from the normal muscles was insignificant. [ABSTRACT FROM AUTHOR]

Omeprazole, a proton pump inhibitor, was labeled with Tc to obtain Tc-omeprazole in ∼96% yield in basic media. The optimum conditions were as follows: pH 9, 50 μg of SnCl·2HO, 30 min, and 3 mg of the substrate. Tc-omeprazole was stable for 6 h. Intravenous biodistribution of Tc-omeprazole showed that it concentrated in the stomach ulcer to reach about 22% of the total injected dose at 1 h post injection. This concentration of Tc-omeprazole in stomach ulcer may be sufficient for ulcer imaging. [ABSTRACT FROM AUTHOR]

Labeling of Meloxicam with Tc was done by direct addition of pertechnetate in isotonic solution to Sn-Meloxicam solution. High labeling yield (98%) was attained in 30 min at room temperature. The effect of various factors on the labeling yield was studied. No less than 0.5 mg of Meloxicam should be used to prevent the formation of colloids in the reaction medium. 75 μg of stannous chloride dihydrate was found to be sufficient to reduce all pertechnetate without the detection of free pertechnetate or colloids in the reaction mixture. The labeling should be done in alkaline solutions (pH 9-11). The labeled compound was separated and purified by HPLC. The biological distribution in infected mice demonstrates the suitability of Tc-labeled Meloxicam for inflammation and tumor imaging. [ABSTRACT FROM AUTHOR]

A procedure was developed for labeling tannic acid with Tc. The following conditions are required to achieve 95.5% yield of Tc-tannic acid: 150 μg of SnCl·2HO, 50 μg of the substrate, 30 min, pH 7. Tc-tannic was stable for 6 h. Experiments on biodistribution of orally administered Tc-tannic acid showed that it is concentrated in the stomach ulcer (50% of the total administrated dose at 1 h post administration). This concentration of Tc-tannic acid in stomach ulcer may be sufficient for ulcer radioimaging. [ABSTRACT FROM AUTHOR]

Quinoxaline 1,4-dioxide derivative, 2-{[benzyl(cyanomethyl)amino]methyl}-3-(ethoxycarbonyl) quinoxaline 1,4-dioxide (QD), was synthesized and labeled with radioiodine via direct electrophilic substitution giving labeling yield above 90%. The product was examined by paper electrophoresis. I-QD was prepared using Chloramine T as oxidizing agent. I-QD was stable for up to 72 h post labeling, in contrast to Tc-AQCD which is stable only for a short time. Biodistribution study of I-QD in ascites tumor bearing mice revealed large uptake of the labeled compound in tumor sites. In addition, in vitro incubation of the labeled compound with Ehrlich cells indicated incorporation of these compounds in DNA of tumor cells. This uptake of I-QD in DNA of tumor cells may be helpful in tumor diagnosis and therapy. [ABSTRACT FROM AUTHOR]

An L-carnitine derivative labeled with Tc was prepared. It is effective in tumor imaging. The labeling was done using SnCl as a reducing agent. The optimum conditions required to label 25 μg of L-carnitine were as follows: 100 μg of SnCl, 30 min reaction time, room temperature, pH 7 (0.5 M phosphate buffer). The radiochemical purity of the labeled compound was determined by paper chromatography. The yield was about 93%. About 2.5 × 10 Ehrlich ascites carcinoma (EAC) cells were injected intraperitoneally to produce ascites and intramuscularly in the right thigh to produce solid tumor in female mice. Biodistribution studies were carried out by injecting a solution of Tc- L-carnitine into normal and tumor-bearing mice. The uptake in ascites and in solid tumor was over 5% of the injected dose per gram tissue at 4 h post injection. These data revealed localization of the tracer in the tumor tissues with high percentage sufficient to use Tc- L-carnitine as a promising tool for diagnosis of tumor. [ABSTRACT FROM AUTHOR]