Sawan, H. S., H. A. Merey, A. M. Mahmoud, and S. A. Atty, "Electrochemical sensor based on ZrO2/ ionic liquid for ultrasensitive simultaneous determination of metoclopramide and paracetamol in biological fluids", Journal of Applied Electrochemistry, vol. 54, pp. 703–718, 2024.
Sawan, H. S., H. A. Merey, A. M. Mahmoud, and S. A. Atty, "Electrochemical sensor based on ZrO2/ ionic liquid for ultrasensitive simultaneous determination of metoclopramide and paracetamol in biological fluids", Journal of Applied Electrochemistry, vol. 54, pp. 703–718, 2024.
Sawan, H. S., H. A. Merey, A. M. Mahmoud, and S. A. Atty, "Electrochemical Sensor based on N-Doped Graphite/Aluminum Silicate Nanocomposite Modified Carbon Paste for Simultaneous Detection of Paracetamol and Pamabrom", Journal of The Electrochemical Society, vol. 171, 2024.
Nazlawya, H. N., H. E. Zaazaa, H. A. Merey, and S. A.Attya, "Green voltammetric nano scaled determination of toldimfos and its residues in cattle meat and milk in presence of its toxic metabolite and Co-administered vitamin C", Sustainable Chemistry and Pharmacy , vol. 31, pp. 100906, 2023.
Farag, M. M., H. B. El-Nassan, H. A. Merey, B. M. Eltanany, M. M. Galal, W. Wadie, D. M. El-Tanbouly, M. A. Khattab, L. A. Rashed, and A. N. ElMeshad, "Comparative pharmacodynamic study delineating the efficacy of amantadine loaded nano-emulsified organogel via intranasal versus transdermal route in rotenone-induced Parkinson’s disease rat model", Journal of Drug Delivery Science and Technology, vol. 86 , pp. 104765, 2023.
Farag, M. M., H. B. El-Nassan, H. A. Merey, B. M. Eltanany, M. M. Galal, W. Wadie, D. M. El-Tanbouly, M. A. Khattab, L. A. Rashed, and A. N. ElMeshad, Comparative pharmacodynamic study delineating the efficacy of amantadine loaded nano-emulsified organogel via intranasal versus transdermal route in rotenone-induced Parkinson’s disease rat model, .
Elmasry, M. S., W. S. Hassan, H. A. Merey, and I. M. Nour, "Earth-friendly micellar UPLC technique for determination of four hypoglycemic drugs in different pharmaceutical dosage forms and spiked human plasma", BMC Chemistry, vol. 17, issue 74, pp. 1-11, 2023. Abstractesraa.pdf

A novel, sensitive, and green micellar UPLC method was proposed and validated for the simultaneous
determination of four hypoglycemic agents used in type II diabetes mellitus treatment namely, pioglitazone,
alogliptin, glimepiride, and vildagliptin. The developed UPLC method was successfully applied for quantitative
analysis of these drugs in bulk, in pharmaceutical formulations, and in spiked human plasma. Chromatographic
separation was carried out on a Kinetex® 1.7 μm XB-C18 100 Å (50 × 2.1 mm) column, using a degassed and filtered
mixture of (0.1 M SDS- 0.3% triethyl amine- 0.1% phosphoric acid (pH 6)) and n-propanol (85:15 v/v), at a flow rate
of 0.2 mL/min. The experimental conditions of the suggested method were well investigated and optimized. The
newly developed micellar UPLC method is capable of determining different dosage forms at the same time with
the same solvents, saving time and effort. The method was found to be efficiently applicable in spiked human
plasma and could be extended to study the pharmacokinetics of the cited drugs in real human plasma samples.
The greenness of the developed method was evaluated by applying the Eco-scale scoring tool, which verified the
excellent greenness of the analytical method.

Ramadan, N. K., H. A. Merey, S. S. Diab, and A. A. Moustafa, "In-Line Green Potentiometric Monitoring of Dissolution Behavior of Losartan Potassium Versus Pharmacopeial Methods: A Comparative Study", Analytical Chemistry letters, vol. 12, 2022. Abstract

Green electro-analytical method was developed and validated for quantitative determination and monitoring of the dissolution behavior of Losartan potassium tablets by in-line potentiometric measurement system with no need for pre-treatment or derivatization of the sample. A sensor was fabricated for in-line determination of Losartan potassium LOS in its dissolution medium utilizing polyvinyl chloride (PVC) based membrane and nitrophenyl octyl ether (NPOE) as a plasticizer. Tetraheptyl ammonium bromide (THAB) was employed as anion exchanger for the first sensor, while cetyltrimethylammonium bromide (CTAB) was used in the second sensor. The proposed method showed fast, stable near Nernstian responses across a relatively wide LOS concentration range (1.0 × 10-5 to 1.0 × 10-2 mol/L) in the case of THAB-based sensor while LOS concentration range was (1.0 x 10-4 - 1.0 x 10-2 mol/L) in case of CTAB-based sensor. The dissolution method
was developed according to FDA regulations using USP apparatus II, 50 rpm rotation speed, at 37.0 ± 0.5°C and 900 mL of deareated double distilled water as the dissolution medium. Dissolution profile was generated over 45 min and compared to those obtained by the official spectrophotometric and HPLC methods. The developed method can be efficiently applied as benchtop real-time in-process analysis of LOS concentration. Greenness assessment using Analytical Eco-scale, National Environmental Method Index (NEMI), Green Analytical Procedure Index (GAPI) and Analytical Greenness (AGREE) calculator was conducted to evaluate and compare the proposed method with the official ones.

Elmasry, M. S., M. A. Hasan, W. S. Hassan, H. A. Merey, and I. M. Nour, "Flourimetric study on antidiabetic combined drugs; empagliflozin and linagliptin in their pharmaceutical formulation and human plasma.", Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, vol. 248, pp. 119258, 2021. Abstract

Empagliflozin and linagliptin are newly approved FDA combination that used for the treatment of type 2 diabetes mellitus (T2DM) under trade name Glxambi. Two spectroflourimetric methods were developed for simple quantitative determination of empagliflozin and linagliptin in their pharmaceutical formulation and human plasma without need any tedious processing operations. Empagliflozin has a native fluorescence nature, therefore can be directly determined by measuring emission peak at 305 nm after excitation at 234 nm. There is no any interference from linagliptin at this emission wavelength. On the other hand, linagliptin is a very weak florescent compound that needs to react with fluorogenic reagent to be quantitatively determined without any reaction of empagliflozin. So, quantitative analysis of linagliptin was achieved by coupling with NBD-Cl which is an electro active halide reagent (targeting only Linagliptin with no effect on empagliflozin). Dark yellow fluorophore with high fluorescence is a result of this reaction and can be measured at emission wavelength 538 nm after excition at wavelength 469 nm. Experimental conditions of the suggested methods were well checked and optimized. The regression plots were found to be linear over the range of 40-1200 ng/mL and 3-700 ng/mL for empagliflozin and linagliptin, respectively. The obtained results by the suggested methods were statistically compared with those obtained by the reported methods, showing no significant difference with respect to accuracy and precision at p = 0.05.