Browsing by Author "El-Rahman M.K.A."

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A comparative study between three stability indicating spectrophotometric methods for the determination of diatrizoate sodium in presence of its cytotoxic degradation product based on two-wavelength selection
(Elsevier, 2015) Riad S.M.; El-Rahman M.K.A.; Fawaz E.M.; Shehata M.A.; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini Street; Cairo; 11562; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October for Modern Sciences and Arts University; 6th of October City; Egypt
Abstract Three sensitive, selective, and precise stability indicating spectrophotometric methods for the determination of the X-ray contrast agent, diatrizoate sodium (DTA) in the presence of its acidic degradation product (highly cytotoxic 3,5-diamino metabolite) and in pharmaceutical formulation, were developed and validated. The first method is ratio difference, the second one is the bivariate method, and the third one is the dual wavelength method. The calibration curves for the three proposed methods are linear over a concentration range of 2-24 ?g/mL. The selectivity of the proposed methods was tested using laboratory prepared mixtures. The proposed methods have been successfully applied to the analysis of DTA in pharmaceutical dosage forms without interference from other dosage form additives. The results were statistically compared with the official US pharmacopeial method. No significant difference for either accuracy or precision was observed. 2015 Elsevier B.V. All rights reserved.
Monitoring of the degradation kinetics of diatrizoate sodium to its cytotoxic degradant using a stability-indicating high-performance liquid chromatographic method
(John Wiley and Sons Ltd, 2017) Fawaz E.M.; El-Rahman M.K.A.; Riad S.M.; Shehata M.A.; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini Street; Cairo; 11562; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October for Modern Sciences and Arts University; 6th of October City; Egypt
The X-ray diagnostic agent sodium diatrizoate (DTA) was studied for chemical degradation. The 3,5-diamino derivative was found to be the alkaline and acidic degradation product. The 3,5-diamino degradate is also the synthetic precursor of DTA and it is proved to have cytotoxic and mutagenic effects. A sensitive, selective and precise high-performance liquid chromatographic stability-indicating method for the determination of DTA in the presence of its acidic degradation product and in pharmaceutical formulation was developed and validated. Owing to the high toxicity of the degradation product, the kinetics of the acidic degradation process was monitored by the developed RP-HPLC method. The reaction was found to follow pseudo-first order kinetics. The kinetic parameters such as rate constant (K) and half-life (t�) were calculated under different temperatures and acid concentrations; activation energy was estimated from the Arrhenius plot. The developed RP-HPLC method depends on isocratic elution of a mobile phase composed of methanol�water (25:75 v/v; pH adjusted with phosphoric acid), and UV detection at 238 nm. The method showed good linearity over a concentration range of 2�100 ?g/mL with mean percentage recovery of 100.04 � 1.07. The selectivity of the proposed method was tested using laboratory-prepared mixtures. The proposed method has been successfully applied to the analysis of DTA in pharmaceutical dosage forms without interference from other dosage form additives and the results were statistically compared with the official USP method. Validation of the proposed method was performed according to International Conference on Harmonization guidelines. Copyright � 2016 John Wiley & Sons, Ltd.
Three different spectrophotometric methods exploiting ratio spectra for the selective determination of iohexol in the presence of its acidic degradate
(Bentham Science Publishers B.V., 2018) El-Rahman M.K.A.; Riad S.M.; Fawaz E.M.; Shehata M.A.; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini Street; Cairo; 11562; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October for Modern Sciences and Arts University; 6th of October city; Egypt
Background: Non-ionic X-ray contrast agents constitute a very important class of pharmaceutical compounds produced in large quantities. Iohexol is an important example of such compounds. Objective: Three simple and selective stability indicating spectrophotometric methods utilizing ratio spectra were proposed for the determination of the widely used X-ray contrast medium, iohexol in the presence of its acidic degradate and in its pharmaceutical formulation. Methods: The first method is the first derivative of ratio spectra method (DD 1 ), the second is the Ratio Difference Method (RD), and the last one is the Mean Centering method (MC). Results: The three proposed methods showed a good linearity over the concentration range of 4-40 ?g.mL -1 . The selectivity of the three developed methods was evaluated by analyzing different laboratory-prepared mixtures and satisfactory results were obtained. Conclusion: Iohexol has been successfully determined in its pure form and pharmaceutical formulation (Omnipaque vials) utilizing the proposed methods with no interference from the present additives. The results obtained by each of the proposed methods were statistically compared to the official United States pharmacopeial method and non-significant difference was obtained regarding accuracy or precision. 2018 Bentham Science Publishers.