Sara I. Aboras

Bio: Sara I. Aboras is an academic researcher from Alexandria University. The author has contributed to research in topics: Medicine & Chromatography. The author has an hindex of 1, co-authored 3 publications receiving 10 citations.

A Review on Analytical Strategies for the Assessment of Recently Approved Direct Acting Antiviral Drugs.

Abstract: Human beings are in dire need of developing an efficient treatment against fierce viruses like hepatitis C virus (HCV) and Coronavirus (COVID-19). These viruses have already caused the death of over two million people all over the world. Therefore, over the last years, many direct-acting antiviral drugs (DAADs) were developed targeting nonstructural proteins of these two viruses. Among these DAADs, several drugs were found more effective and safer than the others as sofosbuvir, ledipasvir, grazoprevir, glecaprevir, voxilaprevir, velpatasvir, elbasvir, pibrentasvir and remdesivir. The last one is indicated for COVID-19, while the rest are indicated for HCV treatment. Due to the valuable impact of these DAADs, larger number of analytical methods were required to meet the needs of the clinical studies. Therefore, this review will highlight the current approaches, published in the period between 2017 to present, dealing with the determination of these drugs in two different matrices: pharmaceuticals and biological fluids with the challenges of analyzing these drugs either alone, with other drugs, in presence of interferences (pharmaceutical excipients or endogenous plasma components) or in presence of matrix impurities, degradation products and metabolites. These approaches include spectroscopic, chromatographic, capillary electrophoretic, voltametric and nuclear magnetic resonance methods that have been reported during this period. Moreover, the analytical instrumentation and methods used in determination of these DAADs will be illustrated in tabulated forms.

HPLC/Fluorescence-Diode Array Detection for Rapid and Reliable Determination of Illegal Synthetic Drugs in Male Sexual Herbal and Honey Remedies: Comparative Study with UFLC-MS.

Abstract: BACKGROUND Nutraceuticals, NTC, as honey and tablets with herbal extract are subjected to adulteration. OBJECTIVE For NTCs claimed to enhance sexual performance, synthetic drugs (sildenafil, tadalafil, avanafil, vardenafil and dapoxetine) are common adulterants, so they were selected to be simultaneously analyzed in the current study. Natural aphrodisiacs (icariin and yohimbine) are claimed to be present in many fake NTCs, so they were also included in the study. METHODS In order to achieve the target of the current study, three liquid chromatographic methods with different unique detectors were developed and validated. RESULTS High performance liquid chromatography (HPLC) with fluorescence detection enables rapid and reliable determination of natively fluorescence yohimbine, tadalafil vardenafil and dapoxetine and it is the first report to analyze these compounds as adulterants in counterfeited NTC. Although diode array detector (DAD) enables the analysis of the seven adulterants, fluorescence detector (FLD) shows better sensitivity and selectivity with lower limits of quantitation and detection (LOQ and LOD). On the other hand, ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) offers the advantages of peak identity confirmation, and it is of comparable sensitivity and the selectivity with HPLC-FD. CONCLUSION One or more of these synthetic drugs were found in the analyzed NTCs while natural aphrodisiacs were absent. HIGHLIGHTS Aphrodisiac nutraceuticals, NTCs, were analyzed for adulterants; Five aphrodisiac synthetic drugs (adulterants) were analyzed; two natural claimed aphrodisiac were analyzed in these NTCs; UFLC-MS, HPLC-DAD/FLD were compared for illicit NTCs analysis; all NTCs show synthetic aphrodisiac presence with absence of natural ones.

Tailoring Two White Chromatographic Platforms for Simultaneous Estimation of Ritonavir-Boosted Nirmatrelvir in Their Novel Pills: Degradation, Validation, and Environmental Impact Studies

Abstract: As long as the COVID-19 pandemic is not over, Pfizer had launched the novel pills Paxlovid® (Nirmatrelvir (NMV) co-packaged with Ritonavir (RIT)) as an effective medication for hospitalized and non-hospitalized patients. Making pharmaceutical analysis greener and more sustainable is lately the main direction of the research community. In these contexts, two fast, green and stability indicating chromatographic methods were designed for the neat quantitative determination of NMV and RIT in their bulk and dosage forms. Method I is deemed as the first electro-driven attempt for the assay of Paxlovid®. Herein, the optimized conditions of the Micellar Electrokinetic Chromatographic (MEKC) method was 50 mM borate buffer at pH 9.2 with 25 mM sodium lauryl sulfate (SDS) being used as the back ground electrolyte (BGE) on a deactivated fused silica capillary (50 cm effective length × 50 μm id). Method II was an isocratic reversed phase HPLC separation method using Zorbax-Eclipse C18 (4.6 × 250 mm, 5 μm particle size) column and 50 mM ammonium acetate buffer at pH 5 and acetonitrile as mobile phase constituents at flow rate 1 mL/min. For sake of simplicity and increasing the sensitivity, single wavelength 210 nm was used for the two methods to assay both drugs. Linear correlations between peak areas and concentration were observed in the ranges of 10–200 μg/mL for NMV and 5–100 μg/mL RIT in both methods. The impact of versatile stress conditions such as hydrolysis, oxidation and photolysis on the stability of NMV and RIT were studied. Fortunately, both methodologies were capable to separate both drugs from their degradants. Thus, the stability indicating power of the methods were proved. The derived methods were statistically validated in agreement with the ICH guidelines. Furthermore, the environmental friendliness and sustainability of these methods were investigated and compared with the cited methods using the holistic multicriteria evaluation tools namely Hexagon, AGREE and RGB12 Methods. Conclusively, the proposed methods offered reliable, feasible, economic, white and stability-indicating alternatives to the cited chromatographic methods.

Detection of metronidazole in honey and metronidazole tablets using carbon dots-based sensor via the inner filter effect.

Abstract: In this work, carbon dots (CDs) with a high quantum yield (22.3%) were easily prepared by hydrothermal pyrolysis of acid fuchsin 6B and hydrogen peroxide at 180°C for 10 h. The resultant CDs possess a narrow size distribution in the range of 2.6 to 3.2 nm and emit blue fluorescence. Interestingly, the absorption band of metronidazole (MTZ) centered at 318 nm can complementary overlap with the excitation band of the as-prepared CDs centered at 320 nm, resulting in an inner filter effect (IFE) in high efficiency. In fact, the fluorescence quenching of the CDs depends on the concentration of MTZ. Therefore, a simple method for the detection of MTZ can be established using the CDs-based sensor via the IFE. The linear range of the proposed method was 0-10 μg mL-1 with the limit of detection as low as 0.257 μg mL-1 . This CDs-based sensor had been applied for the detection of MTZ in honey and MTZ tablets with the recoveries in the range of 98.0% to 105.1% and 95.7% to 106.5%, respectively. Therefore, the as-prepared CDs have a potential to be developed as a MTZ sensor with high selectivity, sensitivity and accuracy.