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Hegazy M.A.E.-M.,Cairo University | Eissa M.S.,Egyptian Russian University | Abd El-Sattar O.I.,National Organization of Drug Control and Research | Abd El-Kawy M.,Cairo University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

Linezolid (LIN) is determined in the presence of its alkaline (ALK) and oxidative (OXD) degradation products without preliminary separation based on ultraviolet spectrophotometry using two-way chemometric methods; principal component regression (PCR) and partial least-squares (PLS), and three-way chemometric methods; parallel factor analysis (PARAFAC) and multi-way partial least squares (N-PLS). A training set of mixtures containing LIN, ALK and OXD; was prepared in the concentration ranges of 12-18, 2.4-3.6 and 1.2-1.8 μg mL-1, respectively according to a multilevel multifactor experimental design. The multivariate calibrations were obtained by measuring the zero-order absorbance from 220 to 320 nm using the training set. The validation of the multivariate methods was realized by analyzing their synthetic mixtures. The capabilities of the chemometric analysis methods for the analysis of real samples were evaluated by determination of LIN in its pharmaceutical preparation with satisfactory results. The accuracy of the methods, evaluated through the root mean square error of prediction (RMSEP), was 0.058, 0.026, 0.101 and 0.026 for LIN using PCR, PLS, PARAFAC and N-PLS, respectively. Protolytic equilibria of LIN and its degradation products were evaluated using the corresponding absorption spectra-pH data obtained with PARAFAC. The obtained pKa values of LIN, ALK and OXD are 5.70, 8.90 and 6.15, respectively. The results obtained were statistically compared to that of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision. © 2014 Elsevier Ltd. All rights reserved.


Hegazy M.A.-M.,Cairo University | Eissa M.S.,Egyptian Russian University | Abd El-Sattar O.I.,National Organization of Drug Control and Research | Abd El-Kawy M.M.,Cairo University
Journal of Pharmaceutical Analysis | Year: 2014

Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride (IMD) in the presence of both its alkaline (AKN) and oxidative (OXI) degradation products and in its pharmaceutical formulation. Method A is the fourth derivative spectra (D4) which allows the determination of IMD in the presence of both AKN and OXD, in pure form and in tablets by measuring the peak amplitude at 243.0 nm. Methods B, C and D, manipulating ratio spectra, were also developed. Method B is the double divisor-ratio difference spectrophotometric one (DD-RD) by computing the difference between the amplitudes of IMD ratio spectra at 232 and 256.3 nm. Method C is the double divisor-first derivative of ratio spectra method (DD-DR1) at 243.2 nm, while method D is the mean centering of ratio spectra (MCR) at 288.0 nm. Methods A, B, C and D could successfully determine IMD in a concentration range of 4.0-32.0 μg/mL. Methods E and F are principal component regression (PCR) and partial least-squares (PLS), respectively, for the simultaneous determination of IMD in the presence of both AKN and OXI, in pure form and in its tablets. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. The accuracy, precision and linearity ranges of the developed methods were determined. The results obtained were statistically compared with those of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision. © 2013 Xi'an Jiaotong University.


Hamza A.A.,United Arab Emirates University | Hamza A.A.,National Organization of Drug Control and Research
Food and Chemical Toxicology | Year: 2010

This study was carried out to evaluate the effect of Moringa oleifera Lam (Moringa) seed extract on liver fibrosis. Liver fibrosis was induced by the oral administration of 20% carbon tetrachloride (CCl4), twice weekly and for 8 weeks. Simultaneously, M. oleifera Lam seed extract (1 g/kg) was orally administered daily. The biochemical and histological results showed that Moringa reduced liver damage as well as symptoms of liver fibrosis. The administration of Moringa seed extract decreased the CCl4-induced elevation of serum aminotransferase activities and globulin level. The elevations of hepatic hydroxyproline content and myeloperoxidase activity were also reduced by Moringa treatment. Furthermore, the immunohistochemical study showed that Moringa markedly reduced the numbers of smooth muscle α-actin-positive cells and the accumulation of collagens I and III in liver. Moringa seed extract showed significant inhibitory effect on 1,1-diphenyl-2-picrylhydrazyl free radical, as well as strong reducing antioxidant power. The activity of superoxide dismutase as well as the content of both malondialdehyde and protein carbonyl, which are oxidative stress markers, were reversed after treatment with Moringa. Finally, these results suggested that Moringa seed extract can act against CCl4-induced liver injury and fibrosis in rats by a mechanism related to its antioxidant properties, anti-inflammatory effect and its ability to attenuate the hepatic stellate cells activation. © 2009 Elsevier Ltd. All rights reserved.


El-Ries M.A.,National Organization of Drug Control and Research | Khaled E.,National Research Center of Egypt | Zidane F.I.,Al - Azhar University of Egypt | Ibrahim S.A.,National Organization of Drug Control and Research | Abd-Elmonem M.S.,National Organization of Drug Control and Research
Drug Testing and Analysis | Year: 2012

The catalytic effect of iodide on the oxidation of four dyes: viz. variamine blue (VB), methylene blue (MB), rhodamine B (RB), and malachite green (MG) with different oxidizing agents was investigated for the kinetic spectrophotometric determination of iodide. The above catalyzed reactions were monitored spectrophotometrically by following the change in dye absorbances at 544, 558, 660, or 617 nm for the VB, RB, MB, or MG catalyzed reactions, respectively. Under optimum conditions, iodide can be determined within the concentration levels 0.064-1.27 μg mL -1 for VB method, 3.20-9.54 μg mL -1 for RB method, 5.00-19.00 μg mL -1 for the MB method, and 6.4-19.0 μg mL -1 for the MG one, with detection limit reaching 0.004 μg mL -1 iodide. The reported methods were highly sensitive, selective, and free from most interference. Applying the proposed procedures, trace amounts of iodide in pharmaceutical and edible salt samples were successfully determined without separation or pretreatment steps. © 2011 John Wiley & Sons, Ltd.


Mahmoud D.B.,National Organization of Drug Control and Research | Shukr M.H.,National Organization of Drug Control and Research | Bendas E.R.,Cairo University
International Journal of Pharmaceutics | Year: 2014

The current investigation was aimed to improve the solubility of poorly soluble drug, cilostazol (CLZ). Self-nanoemulsifying drug delivery system (SNEDDS) composed of oil, surfactant and co-surfactant for both oral and parenteral administration of CLZ was formulated. The components for SNEDDS were identified by solubility studies, and pseudo-ternary phase diagrams were plotted to identify the efficient self-emulsification regions. The optimum formula, composed of Capryol 90 as an oil phase, Cremophor EL as a surfactant, and Transcutol HP as a co-surfactant in a ratio of 19.8:30.5:49.7 by weight, was able to solubilize CLZ 2000 times higher than its solubility in water. This formula was able to form grade "A" nanoemulsion when diluted with water, resulted in emulsification time of 50 ± 1.1 s, particle size of 14.3 nm, PDI of 0.5 and % transmittance was 97.40% ± 0.65. It showed excellent in vitro dissolution of 93.1% and 81.5% after 5 min in 0.3% sodium lauryl sulphate solution and phosphate buffer pH 6.4, respectively when compared with the marketed tablet formulation and drug suspension as the tablets showed only 44.3% and 9.9% while CLZ suspension showed 33.9% and 8.8% in 0.3% sodium lauryl sulphate solution and phosphate buffer pH 6.4, respectively. It was found to be robust to dilution, thermodynamically stable with low viscosity values of 14.20 ± 0.35 cP. In vivo study revealed significant increase in bioavailability of CLZ in rabbits to 3.94 fold compared with the marketed tablet formulation after oral administration. This formula could be sterilized by autoclaving and did not cause significant hemolysis to human blood which indicates its safety for intravenous administration with a 1.12 fold increase in bioavailability compared with its oral administration. Our study illustrated the potential use of SNEDDS of poorly soluble CLZ orally, and its successful administration of parenterally when required in acute cases of myocardial and cerebral infarction. © 2014 Elsevier B.V. All rights reserved.

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