Radiochemical and biological characterization of <Superscript>99<Emphasis Type="Italic">m</Emphasis></Superscript>Tc-oxiracetam as a model for brain imaging

^99mTc-oxiracetam was prepared. It can be used as a radiotracer for brain imaging. Under the optimum conditions (0.5 mg of oxiracetam, 50 μg of SnCl₂·2H₂O, pH 7, room temperature, 30 min), the radio-chemical yield determined by chromatographic methods reached 96%. Biodistribution studies with mice showed that the brain uptake of the complex was 5.1% injected dose per gram (% ID/g) at 5 min post injection. In this parameter, the complex surpasses the commercially available ^99mTc-ECD (4.7% ID/g) and ^99mTc-HMPAO (2.25% ID/g).     

Development and assessment of stable formulations containing two herbal antimicrobials: Allium sativum L. and Eruca sativa miller seed oils

Abstract

Context: Garlic oil and Eruca oil have been reported to have excellent antimicrobial activity. However, the exact knowledge of their required hydrophilic–lipophilic balance (rHLB) values to facilitate their emulsification are still not reported in the literature.

Objective: The objective of this study is to determine rHLB values of Garlic and Eruca oils to formulate an elegant stable cream formulation enriched with both oils.

Materials and methods: Emulsions of both oils were prepared by the bottle method using water, Tween 80 and Span 80. Formulated emulsions were evaluated for creaming index (CI), droplet size, and turbidity to determine rHLB. Utilizing determined rHLB, creams were formulated using a combination of two surfactants, Span 60:Brij 58 (1:2.333) at three different concentrations (2, 4, and 6%).

Results: rHLB of Garlic oil and Eruca oil was determined to be 7.92?±?0.27 and 9.76?±?0.32, respectively. Stable cream (F1) developed with 2% surfactant blend showed elegant rheological properties, the best antimicrobial activity against Staphyococcus aureus ATCC29737, Escherichia coli ATCC25299 S. aureus (MRSA), Malassezia fufur AUMC No. 5173 with no skin irritation. In addition, its texture parameters and pH were found to be consistent over 12 months at 25?±?1?°C and 60% relative humidity.

Discussion: The lowest CI, smallest droplet size, and highest turbidity were obtained at the optimum surfactant concentration in the prepared emulsions. Increasing surfactant blend concentration in cream formulations leads to increasing viscosity and consequently decreasing antimicrobial activity.

Conclusion: Determination of the rHLB of Garlic and Eruca oils allows the ease of preparation of stable, consistent, and non-irritant cream.     

Mössbauer study of the dynamical properties of some lead borate glasses near their transformation temperature

Calcium-lead-borate glasses containing iron were thoroughly studied by Mössbauer effect spectroscopy aiming to determine both their Debye temperature and their transformation temperature during heating. The obtained Mössbauer effect parameters at room temperature exhibit dispersion of iron ions in a low spin ferric state as modifying cations in a pure amorphous glass matrix. The electric field gradient due to the lattice was stabilized at moderate and high lead oxide content glasses. The high-temperature measurements were carried out between 300 and 750 K under vacuum. It can be concluded that the recoil-free fraction decreased and the mean square amplitude of the Mössbauer atom increased as the temperature was increased. From the Inf againstT curve, the Debye temperature of the solid glass can be calculated (_D = 373.8K). The experimentally determined transformation temperature from this study was found to be 665 K, which may be slightly less than the real value.     

Coatings of Conducting Polymers for Corrosion Protection of Mild Steel

The investigation of electrochemical behavior of different conducting polymers, polythiophene (PTh), polypyrrole (PPy) and polyterthiophene (PTTh) on a mild steel (MS) electrode were done. Moreover, the combinations of the conducting polymers PTh and PPy was investigated. The synthesis of all polymeric coatings was done by the cyclic voltammetry technique. The electrochemical impedance spectroscopy (EIS) measurements were used to evaluate the corrosion performance of coated mild steel by different polymers in 0.5 M of different acid solutions (HCl, HClO₄, H₂ C ₂ O ₄, H₃PO₄ and HNO₃). The protection of all polymeric coatings against corrosion of the substrate was promising and the bilayer coating PPy/PTh gave the best protection efficiency in all used acids. The order of efficiency for the different coatings in HCl and HNO₃ solutions was MS/PPy/PTh > MS/PPy > MS/PTTh > MS/PTh but the order in HClO₄, H₃PO₄ and H₂ C ₂ O ₄ solutions was MS/PPy/PTh > MS/PTTh > MS/PPy > MS/PTh.     

Molar volume and magnetic susceptibility of borate glasses containing iron

A glass system was prepared from reagent grade chemicals having the formula 58 mol % B₂O₃ - 22 mol % CaO - (20 - ) mol % Al₂O₃ - mol % Fe₂O₃, where has different values between 2 and 20 mol %.The molar volume () and magnetic susceptibility () of these glasses has been measured as a function of Fe₂O₃ content. The values of and were found to increase as the Fe₂O₃ content in the glass increases in the region between 2 and 8 mol % and in the region where the content is greater than 10 to 16 mol %, while a decrease was found for samples having an Fe₂O₃ content of 10 mol % and more than 16 mol %. These results could be explained by the change in coordination of iron from FeO₆ to FeO₄, and also the change of Fe³⁺ to Fe²⁺ and change of Fe²⁺ from six coordination to four coordination.     

Structural analysis and physical properties of iron–molybdenum lithium-borate glasses

Samples of iron–molybdenum lithium-borate glass were prepared and investigated. Infrared and Mössbauer effect spectroscopy were employed to study the structure of these glasses. Density, molar volume, magnetic susceptibility and electrical resistivity were also measured. It can be concluded that different structural groups, such as BO₃, BO₄, MoO₄, MoO₆, FeO₄ and FeO₆ were detected in the glass network. The dependence of the ratio [Fe²⁺/Fe³⁺] on lithium concentration was clearly observed. The magnetic susceptibility measurements indicated that all these glasses possess paramagnetic character, and the highest magnetic susceptibility value appeared in the sample that contained 20 mol% Li₂O.

The change of dielectric constant and loss with increasing of lithium ions content could be attributed to the assumption that Fe and Mo ions tend to assume network-forming position in the glass compositions studied. And the change of the ac conductivity is attributed to the hopping mechanism of conduction.     

Electron spin resonance and electrical conductivity of vanadate glasses

Electron spin resonance (ESR) and d.c. conductivity were measured for a series of vanadium borophosphate glasses before and after heat treatment. The ESR spectra showed the presence of vanadium in the V⁴⁺ state in all untreated and heat-treated samples free from iron. The variable temperature ESR and d.c. conductivity results obtained on the sample free from iron showed an inflexion at about 140°C. The electrical conductivity was found to decrease on substitution of 1 mol.% V₂O₅ by 1 mol.% Fe₂O₃ which may be due to a decrease in the V⁴⁺/V ratio. However, the electrical conductivity was found to increase on addition of more than 1 mol.% Fe₂O₃ which may be due to possible hopping conduction between Fe²⁺−Fe³⁺, V⁴⁺−Fe³⁺ and Fe²⁺−V⁵⁺. The increase in conductivity in the sample heat treated at 350°C relative to those heat treated at 300°C and 400°C may be due to the variation in the V⁴⁺/V total ratio. The activation energy values for untreated and heat-treated samples were calculated and were found to depend on the variation in the V⁴⁺/V ratio and the microstructure.     

A Comparative Study of Stannous Chloride and Sodium Borohydride as Reducing Agents for the Radiolabeling of 2,3,7,8,12,13,17,18-Octaethyl-21H,23H-Porphine with Technetium-99m for Tumor Imaging

Radiochemistry - 2,3,7,8,12,13,17,18-Octaethyl-21H,23H-porphine (OEP) was successfully radiolabeled with technetium-99m by direct technique using two different reducing agents: stannous chloride...