Sayed Ahmed Shama

Synthesis and spectral characterization of CoxMg1−xAl2O4 as new nano-coloring agent of ceramic pigment

New nano-blue ceramic pigments of Co(x)Mg(1-x)Al(2)O(4) (0< or =x< or =0.1) have been prepared by co-precipitate-combustion as a hybrid method using urea as a fuel at 500 degrees C in open furnace in air atmosphere. The structure of pigment is assigned based on TGA/DTA/DrTGA analyses, X-ray diffraction (XRD) and transmission electron microscopy (TEM). Also, electronic spectra, infrared (IR) and diffuse reflectance spectroscopy (DRS) using CIE L*a*b* parameter measurement techniques were used. The results revealed that the nano-particle size of pigments were obtained in the range 30-38 nm as well as the varying colors and particle size as a result of different calcinations temperatures within the range of 500-1200 degrees C for 2h.

SPECTROPHOTOMETRIC DETERMINATION OF FAMOTIDINE THROUGH OXIDATION WITH N-BROMOSUCCINIMIDE AND CERRIC SULPHATE

ABSTRACT Three simple, accurate, sensitive and selective spectrophotometric methods (A, B and C) for the determination of famotidine (Fam) in bulk sample, in dosage forms and in the presence of its oxidative metabolites are described. The first method A is based on oxidation of the drug by N-bromosuccinimide (NBS) and determination of the unreacted NBS by measuring the decrease in absorbance of Amaranth dye (AM) at a suitable λmax (521 nm). The methods B and C involve addition of excess cerric sulphate and determination of the unreacted Ce(IV) by decrease the red colour of chromotrope 2R (C2R) at λmax 528 nm for method B or decrease the orange pink colour of rhodamine 6G (Rh6G) at λmax 526 nm for method C. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges 0.1–2.4 µg mL−1 for method A and 0.1–2.2 µg mL−1 for methods B and C. The apparent molar absorptivity, Sandell sensitivity, detection and quantitation limits were calculated. For more accurate results, Ringbom optimum concentration ranges were 0.2–2.2 µg mL−1 for method A and 0.2–2.0 µg mL−1 for methods B and C. The stoichiometric ratio between the drug (Fam) and the oxidant (NBS or Ce4+) was estimated. The validity of the proposed methods were tested by analysing pure and dosage forms containing famotidine and in the presence of its oxidative degradates. Statistical treatment of the results reflects that the proposed procedures are precise, accurate and easily applicable for the determination of famotidine in pure form, in pharmaceutical preparations and in the presence of its oxidative degradates.

Synthesis, thermal and spectral characterization of nanosized NixMg1−xAl2O4 powders as new ceramic pigments via combustion route using 3-methylpyrozole-5-one as fuel

New Ni(x)Mg(1-x)Al(2)O(4) nanosized in different composition (0.1≤x≤0.8) powders have been synthesized successively for first time by using low temperature combustion reaction (LTCR) of corresponding metal chlorides, carbonates and nitrates as salts with 3-methylpyrozole-5-one (3MP5O) as fuel at 300°C in open air furnace. Magnesium aluminate spinel (MgAl(2)O(4)) was used as crystalline host network for the synthesis of nickel-based nano ceramic pigments. The structure of prepared samples was characterized by using different techniques such as thermal analysis (TG-DTG/DTA), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). UV/Visible and Diffuse reflectance spectroscopy (DRS) using CIE-L*a*b* parameters methods have been used for color measurements. The obtained results reveal that Ni(x)Mg(1-x)Al(2)O(4) powder of samples is formed in the single crystalline and pure phase with average particle size of 6.35-33.11 nm in the temperature range 500-1200°C. The density, particle size, shape and color are determined for all prepared samples with different calcination time and temperature.

SPECTROPHOTOMETRY MICRODETERMINATION OF SOME ANTIHYPERTENSIVE DRUGS IN PURE FORM AND IN PHARMACEUTICAL FORMULATIONS

Simple, rapid, accurate, precise and sensitive spectrophotometric method for the microdetermination of enalapril maleate (ENM) and lisinopril dihydrate (LIS) has been developed. The method is based on oxidation of the drug by potassium permanganate in acidic medium and determine the unreacted oxidant by measuring the decrease in absorbance for three different acidic dyes; acid red 73 (AR), amaranth dye [acid red 27] (AM) and acid orange 7 (AO) at a suitable λ max (510, 521 and 484 nm for ENM and 509, 521 and 485 nm for LIS), respectively. Regression analysis of Beer’s law plots showed good correlation in the concentration ranges 0.7–12, 0.5–7.6 and 0.6–9.5 µg mL–1 and 0.5–9.0, 0.4–6.1 and 0.4–7.2 µg mL–1 for ENM and LIS using AR, AM and AO, respectively. The apparent molar absorptivity, Sandell sensitivity, detection and quantitation limits are calculated. Statistical treatment of the results reflects that the proposed procedures are precise, accurate and easily applicable for the determination of ENM and LIS in pure and in pharmaceutical preparations.

Radiation-induced grafting of acrylamide and methacrylic acid individually onto carboxymethyl cellulose for removal of hazardous water pollutants

Abstract Carboxymethyl cellulose hydrogels were synthesized by grafting of acrylamide (AAm) and methacrylic acid (MAAc) individually with different concentrations onto carboxymethyl cellulose (CMC) using direct radiation grafting technique. It was found that for both Poly(CMC/AAm) and Poly(CMC/MAAc), the grafting yield and grafting ratio increase with the increasing monomer concentration. Also, it is noted that both grafting ratio and grafting yield of Poly(CMC/AAm) are higher than that of Poly(CMC/MAAc). The effect of different monomer concentrations on gel (%) and swelling behavior was studied. It is found that the increasing monomer concentration increases gel (%). For Poly(CMC/AAm) hydrogels, the swelling behavior decreases with increasing AAm concentration due to high crosslinking hydrogel formation, while as MAAc content increases, swelling behavior increases up to Poly(CMC/MAAc) 1:25 wt%. Swelling kinetics and diffusion mechanism indicate that the water penetration obeys non-Fickian transport mechanism. The structures and properties of the original CMC and the prepared Poly(CMC/MAAc) and Poly(CMC/AAm) were characterized using different analytical tools such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscope (SEM). This study provides a solution to the discharge of different pollutants from wastewater. The adsorption capacity of Poly(CMC/MAAc) and Poly(CMC/AAm) hydrogels toward heavy metals, Cu+2 and Co+2, dyes such as acid blue dye and methyl green, and organic contaminants such as 4-chlorophenol and 2,4-Dichlorophenoxy acetic acid has been investigated.

Radiosynthesis and modified quality control of O-(2-[ 18 F]fluoroethyl)- L -tyrosine ([ 18 F]FET) for brain tumor imaging

O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET) is the most promising radio-labeled amino acid tracer for brain tumor imaging due to the limitation of 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) and L-methyl-[11C]methionine (11C-MET). However, it has some limitations in radiosynthesis and related quality control that make it less frequently used in many PET centers, in this study, we report a new modification of [18F]FET production using a commercially available fully automated GRP SCINTOMICS module overcoming some of the existing limitations along with a suggestion of a simplified quality control procedure with special focus placed on enantiomeric and radiochemical purity. ([18F]FET) was produced in high radiochemical and enantiomeric purity more than 99% and non-decay corrected yield 25±5% in about 55min.