Preparation and evaluation of radioiodinated avanafil: A novel potential radiopharmaceutical for the diagnostic evaluation of erectile dysfunction

Avanafil, a selective second-generation phosphodiesterase-5 inhibitor, was successfully labeled with iodine-125 via electrophilic and different factors affecting the labeling efficiency were studied. The labeled compound exhibited in-vitro stability of more than 24 h with a maximum labeling yield of up to 98.4 ± 1.9 %. Molecular modeling and in-vitro assessment of tracer inhibitory activity were performed to ensure that radiolabeling did not affect its binding ability to the target. Biodistribution studies were performed in normal rats and models of erectile dysfunction. The tracer specifically accumulated in the penis, and the clearance appeared to take place via the hepatobiliary route. Results suggested the usefulness of radiolabeled avanafil as a promising tracer for erectile dysfunction.

Preparation and characterization of poly nano-cerium chloride for 99Mo production based on neutron activation reactions

Different molar ratios of the cerium trichloride heptahydrate to isopropyl alcohol (1:2, 1:3 and 1:5) were studied to choose the optimum ratio, and studied the reaction temperature effect (80, 90 and 100 °C) to determine the optimum temperature for the preparation of poly nano cerium chloride (PNCC). The PNCC-1 was selected among the prepared PNCC batches based on the ⁹⁹Mo sorption properties that confirms the feasibility of using it as a novel effective sorbent material. The structural properties and chemical composition were studied using different techniques and devices such as EDX, XRD, FESEM, FTIR, TGA, and DTA. The sorption capacity was found to be 450 ± 27 and 195 ± 11 mg/g PNCC-1 using the static and dynamic techniques, from 0.01 M NaOH to obtain about 55 and 75% ^99mTc separation efficiency, respectively. The acceptability of the eluate ^99mTc was investigated from the point of view of radiochemical, radionuclidic and chemical purity.

Preparation and characterization of zirconium silico188W-tungstate as a base material for 188W/188Re generator

Zr:W:Si. The optimum gel was prepared using the molar ratio 1:1:7 at pH 8. The ZrSiW gel was investigated by FTIR, XRD, thermal analysis (TGA and DTA), FESEM, XRF, and NAA. Then, XRF and NAA techniques were used to estimate the proportion of the constituents of the gel according to the molecular formula [ZrO₂(Si(WO₄)₂)16H₂O]. ¹⁸⁸W/¹⁸⁸Re generator was prepared based on the selected ZrSi¹⁸⁸W gel, which gives the highest tungsten content (393.3 mg W/g gel) with 75 ± 3% elution yield of ¹⁸⁸Re. Quality control was studied on the ¹⁸⁸Re to make sure its validity for clinical applications.

Improving the separation of Cu(II) from Zn(II) based on an anion exchanger for the preparation a 62Zn/62Cu generator

A separation procedure of (64,67)Cu(II) from (65)Zn(II) was studied for serving (62)Zn/(62)Cu generator preparation. The distribution coefficients of (65)Zn(II) and (64,67)Cu(II) ions from homogeneous medium of hydrochloric acid and acetone onto De-Acidite FF anion exchanger were investigated. Both hydrochloric acid and acetone concentrations are important factors that affect the separation process. Effects of decreasing the HCl concentration from 0.2 to 0.04 M, increasing the acetone concentration from 5% to 80% and different acetone concentrations (5-97%) in 0.2M HCl were also studied on the separation of (64,67)Cu(II) from (65)Zn(II). The exchange capacity of Zn(II) on the De-Acidite FF matrix was obtained as 3.8 meq/g and the(64,67)Cu(II) elution efficiency was 92.5% using 20 ml of 0.2M HCl-60% acetone with flow rate of 2 ml/min.The radionuclidic purity and radiochemical purity of the eluted (64,67)Cu(II) were examined.

Separation and purification of 131I from tellurium material using ion exchange for preparing tetra-butyl ammonium iodide (131I)

A comparison of the distribution coefficients (Kd) of tellurium and iodine-131 (131I) between hydrochloric acid of various concentrations (without and in presence of 0.1 M thiourea) and the cation exchange resin (Dowex50WX8) was studied. The Kd of tellurium and 131I at different concentrations of thiourea in 0.1 M HCl on the Dowex50WX8 was also studied. The results clarified that the maximum uptake of tellurium was 98% on the Dowex50WX8, while the uptakes of 131I and thiourea are 1.96% and 70%, respectively. To purify 131I from thiourea (30%), which is not retained on Dowex50WX8, the remaining solution was shaken with different types of anion exchangers (Dowex21K, Dowex1X8, and Dowex1X2) within 60 min. The most suitable anion exchanger, which gave the maximum uptake of 131I (80%) was Dowex21K. Finally, 131I was re-extracted from Dowex21K into 5 mM TBAB with a separation yield of 98%. Quality control on the separated product of tetra-butyl ammonium iodide (131I) was carried out.

Direct separation of 67Ga citrate from zinc and copper target materials by anion exchange

The separation of 67Ga from zinc and copper target materials using an anion-exchanger (Dowex21K) and 0.1M citrate buffer at pH 6 is described. The gallium-67 was separated in citrate solution and can be directly used for medical applications.