Green micellar factorial design optimized first derivative synchronous spectrofluorimetric method for tripelennamine and diphenhydramine determination in pharmaceutical gel Mona M. Amer, Basma Z. El‐Khateeb Luminescence, 2024 A green micellar synchronous spectrofluorimetric method was developed and validated for simultaneous determination of tripelennamine hydrochloride and diphenhydramine in bulk and combined pharmaceutical formulation. Synchronous fluorescence of tripelennamine hydrochloride and diphenhydramine was determined using Δλ = 60 nm. The first derivative of synchronous fluorescence was computed to resolve overlap in the synchronous fluorescence spectra. Tripelennamine hydrochloride was quantified at 375 nm, whereas diphenhydramine was quantified at 293 nm; each is the zero‐crossing point of the other. As diphenhydramine exhibited weak native fluorescence, micelle enhancement upon incorporation of sodium dodecyl sulfate was considered. Two‐level full factorial design was carried out to optimize experimental parameters. Optimum conditions involved using SDS (2% w/v) along with Teorell and Stenhagen buffer (pH 9). The method was found to be linear over the range 0.2–4.5 and 0.2–5 μg/mL for tripelennamine and diphenhydramine, respectively, with limits of detection 0.211 and 0.159 μg/mL. The method was successfully applied for simultaneous determination of tripelennamine hydrochloride and diphenhydramine in laboratory‐prepared gel containing all possible excipients with mean percent recoveries ±SD 100.59 ± 0.79 and 98.99 ± 0.98 for tripelennamine hydrochloride and diphenhydramine, respectively. The proposed method was proved to be eco‐friendly using different greenness assessment tools.
Green micellar stability-indicating high-performance liquid chromatography method for determination of rupatadine fumarate in the presence of its main impurity desloratadine: Oxidative degradation kinetics study Mona M. Amer, Ahmed A. Habib, Sherin F. Hammad, Amira H. Kamal Journal of Separation Science, 2023 A green micellar stability‐indicating high‐performance liquid chromatography method was developed for rupatadine fumarate determination in existence with its main impurity desloratadine. Separation was attained using Hypersil ODS column (150 × 4.6 mm, 5 μm), the micellar mobile phase consisted of 0.13 M sodium dodecyl sulfate, 0.1 M disodium hydrogen phosphate adjusted by phosphoric acid to pH 2.8 and 10% n‐butanol. The column was maintained at 45◦C and detection was carried out at 267 nm. A linear response was achieved over the range of 2–160 μg/ml for rupatadine and 0.4–8 μg/ml for desloratadine. The method was applied for rupatadine determination in alergoliber tablets and alergoliber syrup without the interference of methyl paraben and propyl paraben present as main excipients. Rupatadine fumarate revealed pronounced susceptibility to oxidation; further study of oxidative degradation kinetics was carried out. Rupatadine was found to follow pseudo‐first‐order kinetics when exposed to 10% H2O2 at 60 and 80°C and the activation energy was found to be 15.69 Kcal/mol. At a lower temperature (40°C), degradation kinetics regression was best fitted as a polynomial quadratic relationship, thus rupatadine oxidation at a lower temperature tends to adopt a second‐order kinetics rate. Oxidative degradation product structure was revealed using infrared and found to be rupatadine N‐oxide at all temperature values.
Stability indicating RP-HPLC method for methylcobalamin determination in different dosage forms: Application to photodegradation kinetics and pH rate profiling Mona M. Amer, Amira H. Kamal, Sherin F. Hammad, Ahmed A. Habib Journal of Separation Science, 2022 A stability‐indicating RP‐HPLC method for methylcobalamin determination was developed. Stress degradation under variable conditions was carried out. Methylcobalamin had pronounced susceptibility to hydrolysis under acidic, alkaline, and photolytic conditions; further study of photolytic degradation kinetics and pH rate profiling over pH range 2–11 was carried out. Photodegradation of methylcobalamin followed zero‐order kinetics with half‐life 0.99 h equivalent to 1971.53 lux. Methylcobalamin followed pseudo‐first‐order kinetics upon exposure to acidic and alkaline hydrolysis with highest stability at pH 5 and least stability at pH 2. Optimization of chromatographic conditions was performed using two level full factorial design, and chromatographic analysis was executed using Inertsil column (250 × 4.6 mm, 5 μm) maintained at 25◦C. Elution was carried out using 25 mM potassium dihydrogen phosphate (pH adjusted with phosphoric acid to 3.8): methanol:acetonitrile (55:35:10, v/v) as mobile phase. The flow rate was 1.0 ml/min. Detection was carried out at 220 nm using diode array detector. The method was validated as per ICH guidelines; the linearity was over concentration range 2–160 μg/ml with coefficient of determination 0.9995. The method was effectively applied for determination of methylcobalamin in Cobalvex ampoule, Cobal tablet, Cobal‐F tablet, and Methyltechon oral dissolvable film without interfering from excipients within run time 6 min.
Stability indicating RP-HPLC method for determination of dimethyl fumarate in presence of its main degradation products: Application to degradation kinetics Ahmed A Habib, Sherin F Hammad, Mona M Amer, Amira H Kamal Journal of Separation Science, 2021 A stability‐indicating reverse phase‐high‐perfromance liquid chromatography method for the quantitative determination of dimethyl fumarate in presence of its main degradation products was developed. The chromatographic conditions were optimized using two‐level full factorial design, chromatographic analysis was performed using Inertsil® column (250 × 4.6 mm, 5 μm) maintained at 25°C. Mobile phase was a mixture of water (pH 2.6 adjusted with phosphoric acid) and methanol (40:60, v/v) at a flow rate 1.0 mL/min, detection was performed at 210 nm using diode array detector. Stress degradation of dimethyl fumarate under acidic, alkaline, neutral, oxidative, photolytic, and thermal conditions was carried out, it was found to be very susceptible to hydrolysis under acidic and alkaline conditions; further investigation of degradation kinetics over pH range 1–9 was carried out. The degradation rate constant (K), t1/2 and t90 were calculated. Dimethyl fumarate show decreasing in stability in the following pH order: 7 < 5 < 3 < 1 < 9. The method was validated as per ICH guidelines, the method was found to be linear over concentration range 10–150 μg/mL with coefficient of determination (r2) 0.9997. The method was successfully applied for dimethyl fumarate determination in Marclerosis® dosage form within run time less than eight minutes without interference from excipients.
Three Spectrophotometric Methods for Determination of Alogliptin Benzoate and Pioglitazone HCl in Combined Tablet Dosage Form Mokhtar M. Mabrouk, Sherin F. Hammad, Fotouh R. Mansour, Mona M. Amer Analytical Chemistry Letters, 2018 Three simple, accurate and precise spectrophotometric methods have been developed and validated for simultaneous determination of alogliptin benzoate and pioglitazone HCl in bulk and in tablet dosage form. Method I was area under curve method and it involved measurement of area at selected wavelength range; the selected wavelength range was 275-285 nm for ALG and 263-273 nm for PIO. Method II involved the use of first derivative of ratio spectra (1DD) using PIO (10 μg/mL) as a divisor for ALG determination, then peak amplitude at 300 nm was directly proportional to ALG concentration; and ALG 5 μg/mL as a divisor for PIO determination, then peak amplitude at 277 nm was directly proportional to PIO concentration. Method III was ratio difference method and it involved measurement of difference in amplitudes (ΔP) in the ratio spectra; ΔP292-238 was directly proportional to ALG concentration and ΔP260-239 was directly proportional to PIO concentration. The three proposed methods were linear over the range 5-30 μg/mL for ALG and 5-50 μg/mL for PIO. The methods were validated according to ICH guidelines. Statistical comparison of the proposed methods with the reported HPLC method using F and t tests showed no significant difference regarding both accuracy and precision.
RECENT SCHOLAR PUBLICATIONS
Review on strategies for analysis of some structurally related pharmaceutical compounds: approach to forced degradation, degradation kinetics and impurity profiling of drugs M Amer, AA Habib, S Hammad, A Kamal Journal of Advanced Medical and Pharmaceutical Research 6 (1), 32-47 , 2025 2025 Citations: 3
Green direct and ratio-based spectrophotometric manipulated methods for tinidazole and ciprofloxacin hydrochloride concomitant assay in their tablet dosage form SM Megahed, MM Amer Green Analytical Chemistry 12, 100197 , 2025 2025
Green micellar factorial design optimized first derivative synchronous spectrofluorimetric method for tripelennamine and diphenhydramine determination in pharmaceutical gel MM Amer, BZ El‐Khateeb Luminescence 39 (7), e4815 , 2024 2024 Citations: 1
Green micellar stability‐indicating high‐performance liquid chromatography method for determination of rupatadine fumarate in the presence of its main impurity desloratadine … MM Amer, AA Habib, SF Hammad, AH Kamal Journal of Separation Science 46 (14), 2300135 , 2023 2023 Citations: 7
Stability indicating RP‐HPLC method for methylcobalamin determination in different dosage forms: Application to photodegradation kinetics and pH rate profiling MM Amer, AH Kamal, SF Hammad, AA Habib Journal of separation science 45 (15), 2877-2886 , 2022 2022 Citations: 14
Stability indicating RP‐HPLC method for determination of dimethyl fumarate in presence of its main degradation products: Application to degradation kinetics AA Habib, SF Hammad, MM Amer, AH Kamal Journal of separation science 44 (3), 726-734 , 2021 2021 Citations: 19
Three Spectrophotometric Methods for Determination of Alogliptin Benzoate and Pioglitazone HCl in Combined Tablet Dosage Form MM Mabrouk, SF Hammad, FR Mansour, MM Amer Analytical Chemistry Letters 8 (3), 368-378 , 2018 2018 Citations: 23
Development and validation of a reversed phase HPLC method for simultaneous determination of antidiabetic drugs alogliptin benzoate and pioglitazone HCl M Mokhtar Der Pharmacia Sinica , 2016 2016 Citations: 25
MOST CITED SCHOLAR PUBLICATIONS
Development and validation of a reversed phase HPLC method for simultaneous determination of antidiabetic drugs alogliptin benzoate and pioglitazone HCl M Mokhtar Der Pharmacia Sinica , 2016 2016 Citations: 25
Three Spectrophotometric Methods for Determination of Alogliptin Benzoate and Pioglitazone HCl in Combined Tablet Dosage Form MM Mabrouk, SF Hammad, FR Mansour, MM Amer Analytical Chemistry Letters 8 (3), 368-378 , 2018 2018 Citations: 23
Stability indicating RP‐HPLC method for determination of dimethyl fumarate in presence of its main degradation products: Application to degradation kinetics AA Habib, SF Hammad, MM Amer, AH Kamal Journal of separation science 44 (3), 726-734 , 2021 2021 Citations: 19
Stability indicating RP‐HPLC method for methylcobalamin determination in different dosage forms: Application to photodegradation kinetics and pH rate profiling MM Amer, AH Kamal, SF Hammad, AA Habib Journal of separation science 45 (15), 2877-2886 , 2022 2022 Citations: 14
Green micellar stability‐indicating high‐performance liquid chromatography method for determination of rupatadine fumarate in the presence of its main impurity desloratadine … MM Amer, AA Habib, SF Hammad, AH Kamal Journal of Separation Science 46 (14), 2300135 , 2023 2023 Citations: 7
Review on strategies for analysis of some structurally related pharmaceutical compounds: approach to forced degradation, degradation kinetics and impurity profiling of drugs M Amer, AA Habib, S Hammad, A Kamal Journal of Advanced Medical and Pharmaceutical Research 6 (1), 32-47 , 2025 2025 Citations: 3
Green micellar factorial design optimized first derivative synchronous spectrofluorimetric method for tripelennamine and diphenhydramine determination in pharmaceutical gel MM Amer, BZ El‐Khateeb Luminescence 39 (7), e4815 , 2024 2024 Citations: 1
Green direct and ratio-based spectrophotometric manipulated methods for tinidazole and ciprofloxacin hydrochloride concomitant assay in their tablet dosage form SM Megahed, MM Amer Green Analytical Chemistry 12, 100197 , 2025 2025
