DINA ABBAS AHMED MOSTAFA

Mamdouh R. Rezk; Mohamed Abdelkawy; Yasmin Rostom

25/11/2023

https://www.sciencedirect.com/science/article/abs/pii/S0026265X2301336X

DINA ABBAS AHMED MOSTAFA

17/08/2023

https://link.springer.com/article/10.1186/s43094-023-00519-8

DINA ABBAS AHMED MOSTAFA

Mamdouh R. Rezk; Mohamed Abdelkawy; Yasmin Rostom

23/07/2023

https://www.sciencedirect.com/science/article/abs/pii/S0731708523003679

DINA ABBAS AHMED MOSTAFA

Yasmin Rostom; Mohamed Abdelkawy; Mamdouh R. Rezk

14/06/2023

https://academic.oup.com/chromsci/advance-article-abstract/doi/10.1093/chromsci/bmad042/7197853

DINA ABBAS AHMED MOSTAFA

Yasmin Rostom; Mohamed Abdelkawy; Mamdouh R. Rezk

13/04/2023

https://www.sciencedirect.com/science/article/abs/pii/S1386142523004225

DINA ABBAS AHMED MOSTAFA

Mohamed Abdelkawy, Mamdouh R. Rezk, Yasmin Rostom

01/04/2023

https://www.sciencedirect.com/science/article/pii/S2211715623001595

DINA ABBAS AHMED MOSTAFA

Mohamed Abdelkawy; Mamdouh R. Rezk; Amr M. Mahmoud; Yasmin Rostom

08/03/2023

https://pubs.rsc.org/en/content/articlehtml/2023/ra/d3ra00597f

DINA ABBAS AHMED MOSTAFA

20/04/2022

https://www.sciencedirect.com/science/article/pii/S138614252200405X

DINA ABBAS AHMED MOSTAFA

Dina Abbas Ahmed

01/05/2021

A comparative study of successive spectrophotometric resolution technique for the simultaneous determination of a challengeable quaternary mixture of Chlorpheniramine maleate (CPM), Pseudoephedrine hydrochloride (PSE), Ibuprofen (IBU) and Caffeine (CAF) is presented, without preliminary physical separation steps. Several successive steps were applied on built-in spectrophotometer software utilizing zero and/or derivative and/or ratio spectra of the studied components. These methods, namely, Dual amplitude difference (DAD) as a novel method, Constant multiplication coupled with spectrum subtraction method (CM-SS), Factorized first derivative coupled with derivative transformation method (FD¹ -DT) and Derivative ratio method (DD¹).The calibration graphs are linear over the concentration range of 10.0–80.0 μg/mL,150.0–900.0 μg/mL, 200.0–1400.0 μg/mL and 3.0–30.0 μg/mL for CPM, PSE, IBU and CAF, respectively. The specificity of suggested methods was studied via laboratory prepared (diverse ratios) mixtures and were successfully applied for Antiflu® capsules' analysis. Moreover, sample enrichment via In Silico (via software of spectrophotometer) and In Lab (via spiking with pure sample) techniques was elected for a pharmaceutical dosage form analysis comprising CPM and PSE as minor components. Accuracy, precision and specificity were between the valid limits. Validation steps were done in accordance with the ICH guidelines. Moreover, statistical comparison was carried out between the obtained and reported results for pure powder form and no significant difference appeared.

DINA ABBAS AHMED MOSTAFA

Dina Abbas Ahmed, Mohamed Khaled Abdel Rahman and Soheir Abdel Fattah Weshahy

01/08/2020

Accurate, rapid and selective reversed phase ultra-performance liquid chromatography method with UV detection has been established and validated for the synchronous determination of aceclofenac (ACE) and diacerin (DIA) in the occurrence of diclofenac sodium and rhein, their main degradation products, respectively. Chromatographic separation was accomplished using Inertsil C-18 column (50 × 2.1 mm i.d., 1.7 μm particle size) in isocratic mode, with mobile phase consisting of 20 mM ammonium acetate buffer:acetonitrile in the ratio of 42:58 (v/v), pH adjusted to 3.00 by using 10% acetic acid, the flow rate of 0.25 mL/min and UV detection was performed at 265 nm. The retention times were 2.00 +/− 0.24, 2.69 +/− 0.19, 4.00 +/− 0.23 and 5.24 +/− 0.25 min for DIA, rhein, ACE and diclofenac sodium, respectively. Excellent linearity was shown over a range of 1.0–150.0 μg/mL and 0.5–87.5 μg/mL with mean percentage recoveries of 98.87 ± 1.19 and 98.84 ± 1.08 for ACE and DIA, respectively. Parameters of precision and accuracy of the method meet the established criteria. The obtained RSD values were quite low and indicate good reproducibility of the method. Thus, the developed method can be used for the combined dosage form analysis and its chemical stability studies.

DINA ABBAS AHMED MOSTAFA

Prof. Dr. Hayam Lotfy, Ass. Prof. Mohamed Khaled Abd El Rahman, Prof. Dr. Soheir Weshahy

01/07/2020

Green analytical chemistry" (GAC) succeeded to become an eco-friendly environmental crucial area in the field of analytical chemistry targeting at the chemical processes' and products' optimization regarding to material consumption, generation of waste and intrinsic safety, toxicity and environmental burdens. For an expressive comparison, an electro-analytical in-line potentiometric selective determination of Doxylamine succinate (DOX) in a multi- component pharmaceutical dosage form containing both Caffeine (CAF) and Paracetamol (PAR) has been successfully developed and validated. A real-time monitoring of the dissolution profile of DOX from its pharmaceutical formulation was achieved by the proposed sensor without any interference from paracetamol or caffeine even without pretreating neither the sample nor its derivatization. A cationic exchanger; Potassium tetrakis (4-chlorophenyl) borate (KTCPB), polyvinyl chloride (PVC) based membrane and a plasticizer; 2-nitrophenyl-octyl-ether (2-NPOE) were employed for the fabrication DOX-selective sensor. The proposed sensor showed Nernstian response slope of 29.8 mV/concentration decades from 10-6 to 10-2 mol L-1. ICH guidelines' validation parameters; linearity, accuracy, precision and robustness were performed on the proposed green eco-friendly potentiometric method.

DINA ABBAS AHMED MOSTAFA

Mohamed K Abd El-Rahman, Soheir A Weshahy

01/06/2020

DINA ABBAS AHMED MOSTAFA

Dina A. Ahmed, Mohamed K. Abd El-Rahman, Soheir A. Weshahy

01/12/2019

Oral pharmaceutical preparation containing pseudoephedrine hydrochloride (PSE) and ibuprofen (IBU) is widely prescribed as over- the- counter (OTC) for treatment of common cold-sinus. Development of four precise and accurate spectrophotometric methods are established for the concurrent determination of (PSE) and (IBU)in this preparation exploiting zero and/or ratio spectra. Method I is a dual wavelength method (DW). method II is a ratio difference method (RD), method III is a constant multiplication coupled with spectrum subtraction method (CM-SS) and method IV is a constant center coupled with spectrum subtraction method (CC-SS). While, absorbance correction method (AC) is successfully established for the determination of (IBU) only exploiting zero order absorption spectra. The calibration curves are linear over the concentration range of 100.0–900.0 μg/mL for (PSE) and 200.0–1000.0 μg/mL for (IBU). No separation steps are required for the spectrophotometric procedures which augments their simplicity. Analyzing synthetic mixtures of the cited drugs evaluated the specificity of the applied methods. Validation of the analysis results have been statistically performed confirming the accuracy and reproducibility of the proposed method through recovery studies which were carried out by following ICH guidelines. Thus, the developed methods can be successfully applied routinely in quality control laboratory.

DINA ABBAS AHMED MOSTAFA

Mohamed Khaled Abdel Rahman, Soheir Abdel Fattah Weshahy,

01/05/2019

Six simple, sensitive and selective spectrophotometric methods based on mathematical filtration technique are presented for concurrent determination of aceclofenac (ACE) and paracetamol (PAR) in presence of their degradation products, namely; diclofenac sodium (DIC) and 4-aminophenol (4-AP), respectively without preliminary physical separation procedures. This technique consists of several consecutive steps applied on built-in spectrophotometer software utilizing zero and/or derivative and/or ratio spectra of the studied components. These methods, namely, dual wavelength (DW), induced dual wavelength (IDW), derivative subtraction (DS) coupled with constant multiplication (CM), ratio difference method (RD), constant center method (CC) and the novel introduced unlimited derivative ratio method (UDD). This novel method has a very powerful competence for the analysis of the challengeable mixtures lacking zero crossing point. The linearity, accuracy and precision ranges of these methods were determined and validated as per ICH guidelines. Moreover, the specificity was checked by analyzing synthetic mixtures of both drugs. These methods were applied for the determination of the cited drugs in pharmaceutical formulation and a statistical comparison of the obtained results was made with each other and with those of reported spectrophotometric method. The comparison of the results of pure powder form showed that there is no significant difference between the proposed methods and the reported method regarding both accuracy and precision.

DINA ABBAS AHMED MOSTAFA

Soheir A. Weshahy , Mohamed K. Abd El-Rahman ,

01/11/2018

Attainment of the dissolution silhouettes of active ingredients in a pharmaceutical formulation containing multiple components is governed by off-line multistep chromatographic and spectroscopic methods. In this work, “Double-Dip” green analytical chemistry (GAC) approach with the eventual aim of progressing in-line potentiometric sensors for simultaneous attainment of the dissolution curves of dual active ingredients in a binary pharmaceutical dosage form is adopted. For the proof of concept, two selective and sensitive sensors were elaborated for the simultaneous detection of the cationic Pseudoephedrine (PSE) and the anionic Ibuprofen (IBU) drugs as well as monitoring their dissolution silhouettes. For detecting the cationic drug (PSE), PSE sensor was elaborated by the usage of potassium tetrakis (4-chlorophenyl)borate (KTCPB) being a cationic exchanger, while IBU sensor was established for detecting the anionic IBU using tridodecylmethyl ammonium chloride (TDC) being an anionic exchanger and 2-nitrophenyl-octyl-ether (2-NPOE) as a plasticizer for both sensors. Developing these novel sensors permits PSE and IBU's detection in bulk powder, in laboratory combinations and in complex dosage form and also their simultaneous in-line monitoring of their dissolution profiles. The benefits of the newly introduced “Double-Dip” approach are emphasized with a notably curtailing in solvent consumption and waste generation