Browsing by Author "El-Maraghy, Christine M"

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Green and white-assessed validated chromatographic methods for Ondansetron purity testing in its pharmaceutical formulations; in silico toxicity profiling of impurities
(Elsevier Inc, 2024-02) El-Maraghy, Christine M; Nour, Mai S; ELbalkiny, Heba T
Drug impurities are seen as a crucial threat to drug safety, specifically when dealing with mutagenic/ toxic impurities. Here, we present LC-MS/MS and HPTLC-densitometric methods for simultaneous quantification of Ondansetron and its four official impurities. For the LC-MS/MS, the isocratic elution was applied using methanol and water containing 0.1 % formic acid in a ratio (70:30 v/v) at a flow rate of 1 mL/min, a stationary phase C18 column (4.6 × 50 mm, 5 µm) and mass detection using the MRM mode. For the HPTLC-densitometric method, the mobile phase consists of ethyl acetate: methanol in a ratio (6:4 v/v), and the UV detection was at 216 nm. The developed methods have been validated per ICH recommendations and then evaluated using five tools for whiteness and greenness assessment, offering promising results in comparison to reported chromatographic methods. Additionally, the toxicity profile of the impurities was expected by the online software; PreADMET and pkCSM. The developed methods are recommended for quality control due to their high analytical performance as well as their sustainability, simplicity, and cost-effectiveness, which improves the surveillance capability.
Implementation of green chemistry to develop HPLC/UV and HPTLC methods for the quality control of Fluconazole in presence of two official impurities in drug substance and pharmaceutical formulations
(Elsevier BV, 2023-06) El-Maraghy, Christine M
Two eco-friendly chromatographic methods were developed for analysis of Fluconazole (FLU) in presence of its official impurities B and C in drug substance and pharmaceutical formulations. For the HPTLC- densitometry, the separation was achieved using silica gel plates and mobile system consisting of ethyl acetate: water: acetic acid (8: 1: 1 v/v/v). The HPLC/UV was conducted on column C18 and a mixture of (water: ethanol) in gradient elution at flow rate 1.5 mL/min. The de- veloped methods were validated according to ICH guidelines and they were able to determine FLU without interference from its two structurally related impurities with an accepted resolution and at low concentration level. The linearity was achieved over the range 50–500 μg/spot for HPTLC and 1-500 μg/mL for HPLC/UV. The LOD and LOQ values were 41.3 and 50 μg/spot for HPTLC and 0.052 and 0.15 μg/mL for HPLC/UV, respectively. The results were statistically com- pared to those obtained by reported methods showing no significant difference in terms of accu- racy and precision. The green character of the developed methods was assessed and compared with reported methods using four different tools; NEMI, analytical eco-scale, GAPI and AGREE. The developed methods were found to be greener than the reported methods.
Response surface optimised photocatalytic degradation and quantitation of repurposed COVID-19 antibiotic pollutants in wastewaters; towards greenness and whiteness perspectives
(CSIRO, 2023-12) Elbalkiny, Heba T; El-Borady, Ola M; Saleh, Sarah S; El-Maraghy, Christine M
Rationale. Certain antibiotics have been repurposed for the management of infected COVID-19 cases, because of their possible effect against the virus, and treatment of co-existing bacterial infection. The consumption of these antibiotics leads to their access to sewage, industrial and hospital effluents, then to environmental waters. This creates a need for the routine analysis and treatment of water resources. Methodology. Detection and quantitation of three repurposed antibiotics: levofloxacin (LEVO), azithromycin (AZI) and ceftriaxone (CEF) were studied in different water samples using LC-MS/MS methods employing a C18 column and a mobile phase consisting of 80% acetonitrile/20% (0.1% formic acid in water) after solid phase extraction on Oasis HLB Prime cartridges. Real water samples were treated with synthesised graphitic carbon nitride (g-C3N4) to remove the three types of antibiotics from contaminated water under experimental conditions optimised by response surface methodology, using Box–Behnken experimental design. Results. The analytical method was validated in the concentration range of 10–5000 ng mL–1 for the three drugs. The removal percentages were found to be 92.55, 98.48 and 99.10% for LEVO, AZI and CEF, respectively, using synthesised g-C3N4. Discussion. The analytical method was used for the estimation of the three cited drugs before and after their removal. The method was assessed using ComplexGAPI as a greenness tool and the RGB 12 algorithm as a whiteness model. The method was applied for the analysis and treatment of real water samples before and after their treatment. It proved to be simple, low-cost and environmentally sustainable.
Successive Stability Indicating Spectrophotometric Technique for Simultaneous Determination of Quetiapine Fumarate and its Three Major Related Compounds
(Bentham Science Publisher, 2018) Mohamed., Ekram H; El-Maraghy, Christine M
Background: Quetiapine Fumarate (QTF) is an atypical antipsychotic drug used to treat mental disorders as depression and schizophrenia. The analysis of the dug in the presence of its precursors, degradants and impurities without interference represents a challenge for the analysts. The regulatory requirements recommended by ICH stated that the impurities above or equal to 0.1 % must be identified, characterized and determined. The aim of this work was to introduce three smart and selective spectrophotometric methods that could resolve the complete overlapping of QTF drug with its three related compounds; namely lactam (LAC), N-oxide (OXD) and des-ethanol (DES) without prior separation or extraction step. Methods: So far there is no spectrophotometric method reported in the literature for the analysis of QTF drug with its three related compounds without interference. The First derivative zero crossing (1D-ZC), Spectrum subtraction (SS), and Simultaneous derivative ratio (S1DD) are well-developed methods used for determination and resolution of multicomponent mixtures. While Ratio difference isosbestic point method is a new method that needs two isoabsorptive points for its application and was successfully adopted for simultaneous estimation of ternary mixtures. Results: The linearity range was found in the range of (6-50 μg/mL) for Quetiapine fumarate, (6-110 μg/mL) for lactam, (4-28 μg/mL) for N-oxide and (6-32 μg/mL) for Des-ethanol. The method validation was performed according to ICH guidelines. The results were statistically compared with a reported HPLC method and no significant difference was obtained. Conclusion: The presented spectrophotometric technique highlighted the significance of different tools such as normalized spectra and isoabsorptive points, especially when combined together for the determination and resolution of complex quaternary mixtures as that of QTF and its three major impurities. The proposed methods were smart, accurate and sensitive and were able to determine the four components showing sever overlap without prior separation. The proposed methods are rapid, cheap eco-friendly (green method) and didn’t require any sophisticated programs and could be easily adopted for the routine determination of complex multicomponent mixtures with minimum sample preparation.
A validated liquid chromatography-tandem mass spectrometric method for the determination of co- administered ranitidine and metronidazole in plasma of human volunteers
(Royal Society of Chemistry, 2021-05) El-Naem, Omnia A; El-Maraghy, Christine M
This work describes the development, optimization and validation of a liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for the simultaneous analysis of co-administered ranitidine (RAN) and metronidazole (MET) in plasma of healthy human volunteers. A simple protein precipitation procedure using 1 mL acetonitrile was applied to extract both drugs and metoclopramide as an internal standard (IS) from plasma. The chromatographic separation was achieved on a C18 column with isocratic elution of the mobile phase consisting of acetonitrile and 0.1% formic acid (90 : 10, v/v) at a flow rate of 0.35 mL min−1. The positive ionization mode was used for detecting the ions, by observing the pairs of transition m/z 314.82 < 176.06 for RAN, m/z 172.03 < 127.95 for MET and m/z 299.86 < 277.10 for IS. The linearity range was from 5–600 ng mL−1 for RAN and 2–40 μg mL−1 for MET. The method was found to be sensitive and accurate with good simple extraction recovery and matrix effect, according to FDA guidelines for bioanalytical methods. The developed method could be applied for further bioavailability studies that could be useful in therapeutic drug monitoring
A validated liquid chromatography-tandem mass spectrometric method for the determination of co-administered ranitidine and metronidazole in plasma of human volunteers†
(Royal Society of Chemistry, 6/21/2021) El-Naem, Omnia A; El-Maraghy, Christine M
This work describes the development, optimization and validation of a liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for the simultaneous analysis of co-administered ranitidine (RAN) and metronidazole (MET) in plasma of healthy human volunteers. A simple protein precipitation procedure using 1 mL acetonitrile was applied to extract both drugs and metoclopramide as an internal standard (IS) from plasma. The chromatographic separation was achieved on a C18 column with isocratic elution of the mobile phase consisting of acetonitrile and 0.1% formic acid (90 : 10, v/v) at a flow rate of 0.35 mL min−1. The positive ionization mode was used for detecting the ions, by observing the pairs of transition m/z 314.82 < 176.06 for RAN, m/z 172.03 < 127.95 for MET and m/z 299.86 < 277.10 for IS. The linearity range was from 5–600 ng mL−1 for RAN and 2–40 μg mL−1 for MET. The method was found to be sensitive and accurate with good simple extraction recovery and matrix effect, according to FDA guidelines for bioanalytical methods. The developed method could be applied for further bioavailability studies that could be useful in therapeutic drug monitoring.