EMAN MOHAMED FARAG MAHMOUD MORGAN

Yasmin Mohamed Fayez; M. Abdelkawy; Shereen A. Boltia; Reem H. Obaydo

01/09/2023

https://www.sciencedirect.com/science/article/abs/pii/S2352554123002590

EMAN MOHAMED FARAG MAHMOUD MORGAN

Shereen A. Boltia; Yasmin M. Fayez; M. Abdelkawy

18/05/2023

https://www.sciencedirect.com/science/article/pii/S2405844023034916

EMAN MOHAMED FARAG MAHMOUD MORGAN

Yasmin Mohammed Fayez,

22/12/2021

https://academic.oup.com/jaoac/article-abstract/105/3/717/6478289

EMAN MOHAMED FARAG MAHMOUD MORGAN

Yasmin Mohammed Fayez, Mohamed K. Abd El-Rahman

01/07/2019

The possibility of obtaining continuous analytical signal excluding any pre-treatment of sample is the most environmental friendly method of analysis. In the current manuscript, a solid contact sensor was fabricated for dual purpose; firstly, determination of valaciclovir hydrochloride (VAL) in existence of its acid induced degradation product, Guanine (GUA) and secondly, real time acquisition of the dissolution profile from its pharmaceutical formulations (Valtrex) and (Valysernex). The sensing membrane was fabricated using a polyvinyl chloride (PVC), sodium tetraphenyl borate as a cation exchanger with bis (2-ethylhexyl) sebacate as a plasticizer. The proposed sensor displayed fast, stable Nernstian responses across VAL concentration range (1 × 10−5 M to 1 × 10−2 M). The opportunities of the proposed sensor with respect to other off-line classical techniques originates from being in-line, time saving, cost-effective, green and simple. ICH guidelines were followed to ensure validation of the proposed method concerning accuracy and precision.

EMAN MOHAMED FARAG MAHMOUD MORGAN

Yasmin Mohamde Fayez

01/09/2016

Simple, cost-effective, safe, accurate, precise and environmentally friendly spectro-photometric methods were developed and validated for the quantitative determination of valaciclovir (VAL) in the presence of its related impurity in bulk powder and in its pharmaceutical preparation. This related impurity namely guanine (GUA) is the potential and synthesis impurity of VAL. The spectra of VAL and GUA show the same geometrical features with different absorptivities, so their resolution is very challengeable. A Comparative study was conducted for the results of the conventional methods namely, dual wavelength (DW), first derivative of ratio spectra (1DD) and mean centering of ratio spectra (MCR) versus the recently developed methods namely, induced dual wavelength (IDW), ratio difference (RD) and constant center (CC). The optimized methods allow the estimation of VAL in the concentration range 5-50 μg/mL. The methods were validated as per ICH guidelines and the specificity was assessed by analyzing synthetic mixtures containing different percentages of the related impurity with the drug. The obtained results were compared with that of the official HPLC method by using one-way analysis of variance (ANOVA) and proved to be suitable for quality control laboratories.