Use of radiopharmaceuticals for imaging hypoxic tissues [Hipoksik dokularin görüntülenmesinde radyofarmasötiklerin klinik kullanimi]

Hypoxia is the state between oxygen absence and normal oxygenation of the healthy tissue and when the oxygen necessity for normal cell function goes beyond the sources, cells respond to this situation by down-regulating their metabolism. This hypoxic condition is observed in various clinically significant diseases primarily cancer. Tumor hypoxia may increase resistance to radiation therapy and to some forms of chemotherapy. That is why detection of hypoxia is important. Radiolabelled nitroimidazoles, misonidazole analogues, iodoazomycin nucleosides are used for imaging hypoxia

Determination of in vivo behavior of mitomycin C-Loaded O/W soybean oil microemulsion and mitomycin C solution via gamma camera imaging

PubMed ID: 23659461In this study, a microemulsion system was evaluated for delivery of mitomycin C (MMC). To track the distribution of the formulated drug after intravenous administration, radiochemical labeling and gamma scintigraphy imaging were used. The aim was to evaluate a microemulsion system for intravenous delivery of MMC and to compare its in vivo behavior with that of the MMC solution. For microemulsion formulation, soybean oil was used as the oil phase. Lecithin and Tween 80 were surfactants and ethanol was the cosurfactant. To understand the whole body localization of MMC-loaded microemulsion, MMC was labeled with radioactive technetium and gamma scintigraphy was applied for visualization of drug distribution. Radioactivity in the bladder 30 minutes after injection of the MMC solution was observed, according to static gamma camera images. This shows that urinary excretion of the latter starts very soon. On the other hand, no radioactivity appeared in the urinary bladder during the 90 minutes following the administration of MMC-loaded microemulsion. The unabated radioactivity in the liver during the experiment shows that the localization of microemulsion formulation in the liver is stable. In the light of the foregoing, it is suggested that this microemulsion formulation may be an appropriate carrier system for anticancer agents by intravenous delivery in hepatic cancer chemotherapy. © Copyright 2013, Mary Ann Liebert, Inc. 2013

Comparative bone uptake study of alendronate sodium from vaginal suppositories prepared with polyethylene glycol and massa estarinum bases [Polietilen glikol ve massa estarinum si{dotless}vaglari{dotless} kullani{dotless}larak hazi{dotless}rlanan vajinal supozituvarlardan sali{dotless}nan alendronat sodyumun kemik tutulumunun karşi{dotless}laşti{dotless}rmali{dotless} incelenmesi]

The aim of this study was to compare the bone uptake of alendronate sodium (ALD) from vaginal suppositories prepared with massa estarinum AB (ME) and polyethylene glycol 1500 (PEG) bases. For this purpose, ALD was radiolabeled with 99mTecnetium Pertechnetate (99mTc) by direct method. Radiochemical purity and stability of 99mTc-ALD was performed with chromatographic studies. 99mTc-ALD containing suppositories were prepared with ME and PEG bases. Physical properties of suppositories were evaluated. The physicochemical diffusion study was carried out to compare the release of ALD from different suppository bases. The bone uptake of 99mTc-ALD was observed by gamma scintigraphy studies. 99mTc-ALD containing suppositories were administrated to rabbits via vaginal route. The scintigraphic images were obtained with a gamma camera at different time intervals up to 240 minutes. According to our studies, radiochemical purity of 99mTc-ALD was observed more than 95% up to 6 hours. At 240 minutes of physicochemical diffusion studies, released ALD has 0.620 ± 0.091 mm and 10.465 ± 0.651 mm diameter zone from ME and PEG base suppositories respectively. According to the gamma scintigraphy studies, although no bone uptake observed after ME suppositories application, rabbit's bones were clearly visible after PEG suppositories applied. The results of physicochemical diffusion and gamma scintigraphy studies were found compatible in each other