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Dive into the research topics where Mohammed W.I. Nassar is active.

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Featured researches published by Mohammed W.I. Nassar.


Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2015

Different approaches in manipulating ratio spectra applied for the analysis of Cefprozil in presence of its alkaline-induced degradation product: a comparative study.

Khalid A.M. Attia; Mohammed W.I. Nassar; Mohamed B. El-Zeiny; Ahmed Serag

Four simple, accurate and precise stability-indicating spectrophotometric methods manipulating ratio spectra were developed and validated for simultaneous determination of Cefprozil (CZ) and its alkaline-induced degradation product (DCZ) without prior separation namely; ratio difference, mean centering, derivative ratio using Savitsky-Golay filter and continuous wavelet transform. The accuracy, precision and linearity ranges of the proposed methods were determined. The methods were validated and the specificity was assessed by analyzing synthetic mixtures containing the drug and its degradate. The four methods were applied for the determination of the cited drug in tablets and the obtained results were statistically compared with those of a reported method. The comparison showed that there are no significant differences between the proposed methods and the reported method regarding both accuracy and precision.


Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2016

Different spectrophotometric methods applied for the analysis of binary mixture of flucloxacillin and amoxicillin: A comparative study.

Khalid A.M. Attia; Mohammed W.I. Nassar; Mohamed B. El-Zeiny; Ahmed Serag

Three different spectrophotometric methods were applied for the quantitative analysis of flucloxacillin and amoxicillin in their binary mixture, namely, ratio subtraction, absorbance subtraction and amplitude modulation. A comparative study was done listing the advantages and the disadvantages of each method. All the methods were validated according to the ICH guidelines and the obtained accuracy, precision and repeatability were found to be within the acceptable limits. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can be used for the routine analysis of flucloxacillin and amoxicillin in their binary mixtures.


Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2016

Zero order and signal processing spectrophotometric techniques applied for resolving interference of metronidazole with ciprofloxacin in their pharmaceutical dosage form

Khalid A.M. Attia; Mohammed W.I. Nassar; Mohamed B. El-Zeiny; Ahmed Serag

Four rapid, simple, accurate and precise spectrophotometric methods were used for the determination of ciprofloxacin in the presence of metronidazole as interference. The methods under study are area under the curve, simultaneous equation in addition to smart signal processing techniques of manipulating ratio spectra namely Savitsky-Golay filters and continuous wavelet transform. All the methods were validated according to the ICH guidelines where accuracy, precision and repeatability were found to be within the acceptable limits. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can therefore be used for the routine analysis of ciprofloxacin in quality-control laboratories.


Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2017

Firefly algorithm versus genetic algorithm as powerful variable selection tools and their effect on different multivariate calibration models in spectroscopy: A comparative study.

Khalid A.M. Attia; Mohammed W.I. Nassar; Mohamed B. El-Zeiny; Ahmed Serag

For the first time, a new variable selection method based on swarm intelligence namely firefly algorithm is coupled with three different multivariate calibration models namely, concentration residual augmented classical least squares, artificial neural network and support vector regression in UV spectral data. A comparative study between the firefly algorithm and the well-known genetic algorithm was developed. The discussion revealed the superiority of using this new powerful algorithm over the well-known genetic algorithm. Moreover, different statistical tests were performed and no significant differences were found between all the models regarding their predictabilities. This ensures that simpler and faster models were obtained without any deterioration of the quality of the calibration.


Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2016

Stability-indicating methods for the analysis of ciprofloxacin in the presence of its acid induced degradation product: A comparative study.

Khalid A.M. Attia; Mohammed W.I. Nassar; Mohamed B. El-Zeiny; Ahmed Serag

Four rapid, simple, accurate and precise spectrophotometric methods were used for the determination of ciprofloxacin in the presence of its acidic degradation product. The methods under study are ratio derivative, ratio difference, mean centering and dual wavelength. All the methods were validated according to the ICH guidelines and the obtained accuracy, precision and repeatability were found to be within the acceptable limits. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can be used for the routine analysis of ciprofloxacin in quality-control laboratories.


Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2016

Effect of genetic algorithm as a variable selection method on different chemometric models applied for the analysis of binary mixture of amoxicillin and flucloxacillin: A comparative study

Khalid A.M. Attia; Mohammed W.I. Nassar; Mohamed B. El-Zeiny; Ahmed Serag

Different chemometric models were applied for the quantitative analysis of amoxicillin (AMX), and flucloxacillin (FLX) in their binary mixtures, namely, partial least squares (PLS), spectral residual augmented classical least squares (SRACLS), concentration residual augmented classical least squares (CRACLS) and artificial neural networks (ANNs). All methods were applied with and without variable selection procedure (genetic algorithm GA). The methods were used for the quantitative analysis of the drugs in laboratory prepared mixtures and real market sample via handling the UV spectral data. Robust and simpler models were obtained by applying GA. The proposed methods were found to be rapid, simple and required no preliminary separation steps.


Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2016

Stability indicating methods for the analysis of cefprozil in the presence of its alkaline induced degradation product.

Khalid A.M. Attia; Mohammed W.I. Nassar; Mohamed B. El-Zeiny; Ahmed Serag

Three simple, specific, accurate and precise spectrophotometric methods were developed for the determination of cefprozil (CZ) in the presence of its alkaline induced degradation product (DCZ). The first method was the bivariate method, while the two other multivariate methods were partial least squares (PLS) and spectral residual augmented classical least squares (SRACLS). The multivariate methods were applied with and without variable selection procedure (genetic algorithm GA). These methods were tested by analyzing laboratory prepared mixtures of the above drug with its alkaline induced degradation product and they were applied to its commercial pharmaceutical products.


Journal of AOAC International | 2017

Molecular and Quantum Mechanical Study for the Separation of Cefprozil in the Presence of Its Alkaline Degradation Product Using RP-HPLC with UV Detection

Khalid A.M. Attia; Mohammed W.I. Nassar; Mohamed B. El-Zeiny; Ahmed Serag

A reversed-phase HPLC method (RP-HPLC) with UV detection was developed and validated for the quantitative determination of cefprozil, a second-generation cephalosporin. Due to β-lactam ring instability under alkaline conditions, this RP-HPLC method was applied for the determination of cefprozil in the presence of its possible degradation product. The interactions that govern the separation process with stationary phase were investigated at both molecular and quantum mechanical levels. Moreover, electrostatic potential maps were generated to determine the sites of interaction with mobile phase. The suggested method was validated in compliance with International Conference on Harmonization guidelines and successfully applied for the determination of cefprozil in its commercial pharmaceutical formulation.


Analytical Chemistry Letters | 2017

HPLC Method for the Simultaneous Estimation of Aspirin and Omeprazole in their New Combination

Mohammed W.I. Nassar; Khalid A.M. Attia; Ahmed A. Mohamed; Mohamed Shahin

Abstract A simple, sensitive, accurate and precise RP-HPLC method was developed for simultaneous estimation of aspirin and omeprazole in bulk powder and pharmaceutical formulation. The separation process was developed under optimized chromatographic conditions using a reversed phase of C18 column and a mobile phase consists of acetonitrile-water (60:40 v/v) adjusted to pH 2.9 with o-phosphoric acid. The flow rate used was 1 ml/min and UV detection at 240 nm. The retention time of aspirin and omeprazole was found to be 3.076 and 5.329 min respectively. The method was found to be linear over a concentration range of 10-100 μg/ml and 4-80 μg/ml for aspirin and omeprazole, respectively. The method was validated according to ICH guidelines and the results were satisfactory. Hence, the proposed method could be applied for the routine quality control analysis of this new combination in pure powder and pharmaceutical formulation.


Analytical Chemistry Letters | 2018

Application of Genetic Algorithm as a Variable Selection in Partial Least Square and Artificial Neural Network for the Simultaneous Analysis of Sacubitril and Valsartan in their Recently Approved Pharmaceutical Preparation

Khalid A.M. Attia; Mohammed W.I. Nassar; Ahmed El-Olemy; Sherif Ramzy

Abstract Two smart chemometric models have been applied for quantitative spectral analysis of recently approved binary mixture of sacubitril and valsartan namely; partial least squares and artificial neural networks. Moreover, effect of genetic algorithm as a powerful variable selection technique on the two models has been studied. Genetic algorithm has improved the predictive ability of the models and reduces its complexity by elimination of irrelevant variables. The proposed methods have been successfully applied for the determination of the two drugs in Entresto® tablets. Statistical comparisons between the obtained results and those obtained by the reported method have been performed showing no significant differences by applying t-test and F-test.

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