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•Fluorescence quenching process has been introduced for the determination of Mirabegron by quenching tyrosine and L-tryptophan fluorophores.•The developed methods were validated as ...per ICH guidelines and the obtained results were statistically analyzed.•Stern-Volmer relationship was studied at different temperatures for the quenching mechanism recognition which is static or dynamic.•The double log plots were constructed to evaluate binding sites and binding constants.•Greenness of the proposed methods has been assessed to clarify the extent of environmental safety.
Green spectrofluorimetric methods have been adopted for the determination of Mirabegron (MG) in pure drug and pharmaceutical dosage form. The developed methods based on fluorescence quenching of tyrosine and L-tryptophan amino acids fluorophores by the effect of Mirabegron as a quencher. Experimental conditions of the reaction were studied and optimized. The Fluorescence quenching (ΔF) values were proportional to the concentration range of MG 2–20 μg/ml for the tyrosine-MG system in buffered media pH 2 and 1–30 μg/ml for L-tryptophan-MG system pH 6. Good correlation coefficients with low detection limits of 0.163 and 0.234 μg/ml for the two systems respectively. Method validation was applied according to ICH guidelines. The cited methods were successively applied for MG determination in tablet formulation. No statistically significant difference between the results of the cited and the reference methods regarding t and F tests. The proposed spectrofluorimetric methods are simple, rapid, eco-friendly and can contribute to MG’s methodologies in quality control labs. Stern-Volmer relationship, the effect of temperature, quenching constant (Kq), and UV spectra were studied to identify the mechanism by which the quenching might occur. The results demonstrated that fluorescence quenching of tyrosine was a dynamic quenching process and L-tryptophan was static. The double log plots were constructed to determine the binding constants and binding sites. The greenness profile of the developed methods has been assessed by Green Analytical procedure index (GAPI) and Analytical Greenness Metric Approach (AGREE).
Abstract
This paper presents a novel potentiometric approach for the determination of palonosetron HCl using two sensors; ionophore-free and ionophore-doped ones. The two sensors successfully ...determined the cited drug in the range of 1 × 10
–5
–1 × 10
–2
M with respective Nernstian slopes of 54.9 ± 0.25 and 59.3 ± 0.16 mV/decade. Incorporating calix8arene as an ionophore resulted in a lower detection limit (LOD = 3.1 × 10
–6
M) and enhanced selectivity when compared to the ionophore-free sensor (LOD = 7.9 × 10
–6
M). This modification was also associated with faster response for the ionophore-doped sensor (response time = 20 s) compared to the ionophore-free one (response time = 30 s). The two sensors showed a stable response over a pH range of 3.0–8.0. They successfully determined palonosetron HCl in presence of its oxidative degradation products. They were also used for direct determination of the drug in commercially available parenteral solution without any interference from other dosage forms’ additives.
A selective reversed phase high performance liquid chromatography/photodiode array detector (RP-HPLC/PAD) method has been developed for simultaneous determination of the three co-administrated ...deflazacort, aprepitant and granisetron drugs used with chemotherapy. The three cited drugs have been chromatographed on C18 column using a mobile phase consisting of acetonitrile-0.2% v/v triethylamine (80:20 v/v, pH of 6.6 ± 0.05) with isocratic elution and monitored by photodiode array at 220 nm. International conference on harmonization (ICH) guidelines were followed to validate the developed method. Successful application of the developed method was assessed by the simultaneous determination of the studied drugs in pure forms, dosage forms and plasma samples in the ranges of 0.2-20, 0.4-40 and 0.2-20 μg/mL for deflazacort, aprepitant and granisetron, respectively.
Purpose The purpose of this study is to utilize two types of gypsum mold wastes from two different factories as novel and economical reinforcing fillers for composites that may be useful for building ...materials and floors. Two types of gypsum mold wastes from two different factories as raw materials were incorporated into linear low density polyethylene (LLDPE) aiming to get rid of that waste in one hand and obtaining useful economical composites suitable for building materials and floors. Design/methodology/approach Composites were prepared from two types of gypsum mold wastes substituted with different ratios from raw gypsum and LLDPE throughout the melt blending technique. The physico-mechanical and electrical investigations in addition to the morphology of the composites were included. Findings The mechanical results illustrate that substituting commercial gypsum with gypsum mold waste positively affects tensile strength, flexural strength and hardness shore D for the LLDPE composites. The tensile strength increased from 5 MPa for LLDPE filled with commercial gypsum as blank samples to 11.2 and 13.2 MPa for LLDPE filled with D and S waste. Also, electrical properties which include both permittivity ɛ ′ and dielectric loss ɛ ″ increased with increasing the waste content in the LLDPE matrix. In addition to the electrical conductivity values, σ lies in the order of insulation materials. Consequently, it is possible to produce materials with a gypsum matrix by adding industrial waste, improving the behavior of the traditional gypsum and enabling those composites to be applied in various construction applications as eco-friendly tiles. Originality/value This study aims to prepare eco-friendly composites based on LLDPE and waste gypsum mold to preserve resources for the coming generations, other than lowering the environmental footprint and saving the costs of getting rid of it.
Antiepileptic drugs are among the most common medications that require therapeutic drug monitoring (TDM). Indeed, TDM provides a realistic approach to adjust drug doses for epilepsy based on plasma ...concentrations to optimize its clinical outcome. The most common technique for TDM is high‐performance liquid chromatography, which has a very low green profile among analytical techniques. Perampanel (PER) is an inherently fluorescent compound that its fluorophore readily allows sensitive and quantitative measurements. This paper describes the development and validation of a sensitive, specific, and eco‐friendly spectrofluorimetric method for the determination of PER. Experimental parameters affecting fluorescence intensity of the compound, including solvent dilution, temperature, and excitation wavelength, were studied and optimized. The developed spectrofluorimetric method was established in acetonitrile at λex = 295 nm and λem = 431 nm over a concentration range of 5–60 ng/ml. The adopted method was applied for the determination of PER in human plasma; it was effective in the range of 15–50 ng/ml. The proposed method was found to be sensitive and specific for PER and can be applied successfully in TDM of PER and in quality control laboratories.
Therapeutic drug monitoring (TDM) provides a realistic approach to adjust drug doses for epilepsy based on plasma concentrations to optimize its clinical outcome. A sensitive and eco‐friendly spectrofluorimetric method was developed for the determination of perampanel (PER). The developed method was established at λex = 295 nm and λem = 431 nm over a range of 5–60 ng/mL. The method was applied for the determination of PER in human plasma; it was effective in the range of 15–50 ng/mL.
Common antiepileptic drugs have complex pharmacokinetic characteristics leading to fluctuation in their plasma levels at the same therapeutic doses. Therefore, antiepileptic drugs turn out to be ...among the most common medications for which therapeutic drug monitoring (TDM) is crucial. Indeed, TDM provides a realistic approach to adjust drug doses in epilepsy care based on plasma concentrations to optimize its clinical outcome. Perampanel (PER) is an antiepileptic drug used for the treatment of primary generalized tonic-clonic seizures in combination with other drugs, such as carbamazepine (CAR). Drug-drug pharmacokinetic interactions are very common in this combination, which makes TDM of PER essential. A selective, accurate, and precise bioanalytical method has been developed for the simultaneous determination of PER and CAR in human plasma for the purpose of TDM. Liquid-liquid extraction using ethyl acetate was applied for sample preparation, and diazepam (DZP) was the internal standard. The adopted method could successfully determine PER and CAR within their
c
max
levels as the linearity range was 0.2–10 µg/mL for PER and 5–100 µg/mL for CAR. The chromatographic separation was achieved on a C8 column using acetonitrile, aqueous 0.1% glacial acetic acid (75 : 25, v/v) as a mobile phase in isocratic elution at a flow rate of 0.8 mL/min and an UV detection at 225 nm. The adopted method was validated according to EMA guidelines, and the results were within the acceptance criteria.
Apixaban and Tirofiban Hydrochloride are low molecular weight anticoagulants. The two drugs exhibit native fluorescence that allow the development of simple and valid spectrofluorimetric methods for ...the determination of Apixaban at λ ex/λ em=284/450nm and tirofiban HCl at λ ex/λ em=227/300nm in aqueous media. Different experimental parameters affecting fluorescence intensities were carefully studied and optimized. The fluorescence intensity-concentration plots were linear over the ranges of 0.2–6μgml−1 for apixaban and 0.2–5μgml−1 for tirofiban HCl. The limits of detection were 0.017 and 0.019μgml−1 and quantification limits were 0.057 and 0.066μgml−1 for apixaban and tirofiban HCl, respectively. The fluorescence quantum yield of apixaban and tirofiban were calculated with values of 0.43 and 0.49. Method validation was evaluated for linearity, specificity, accuracy, precision and robustness as per ICH guidelines. The proposed spectrofluorimetric methods were successfully applied for the determination of apixaban in Eliquis tablets and tirofiban HCl in Aggrastat intravenous infusion. Tolerance ratio was tested to study the effect of foreign interferences from dosage forms excipients. Using Student's t and F tests, revealed no statistically difference between the developed spectrofluorimetric methods and the comparison methods regarding the accuracy and precision, so can be contributed to the analysis of apixaban and tirofiban HCl in QC laboratories as an alternative method.
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•New validated spectrofluorimetric methods for the analysis of selected anticoagulants.•The developed methods are successfully applied for the analysis of selected drugs in drug substances and drug products.•The methods are based on the measurements of the native fluorescence of selected drugs.•The proposed methods can be used as alternative methods in quality control laboratories.
Economic and enantioselective synchronous fluorescence spectroscopy and high‐performance thin‐layer chromatography methods have been developed and validated as per ICH guidelines for the separation ...of zopiclone enantiomers using L‐(+)‐tartaric acid as a chiral selector, followed by determination of the chiral‐switching eszopiclone. Synchronous fluorescence spectroscopy was successfully applied for chiral recognition of R & S enantiomers of zopiclone at ∆λ = 110 nm based on creating of diastereomeric complexes with 0.06M tartaric acid in an aqueous medium containing 0.2M disodium hydrogen orthophosphate. Synchronous fluorescence intensities of eszopiclone were recorded at 296 nm in concentration range 0.2‐ to 4‐μg/mL eszopiclone. High‐performance thin‐layer chromatography method depends on resolution of zopiclone enantiomers on achiral HPTLC silica‐gel plates using acetonitrile:methanol:water (8:2:0.25, v/v/v) containing L‐(+)‐tartaric acid as a chiral mobile‐phase additive followed by densitometric measurements at 304 nm in concentration range of 1 to 10 μg/band of eszopiclone. The effect of chiral‐selector concentration, pH, and temperature on the resolution have been studied and optimized for the proposed methods. The cited procedures were successfully applied to determine eszopiclone in commercial tablets of pure and racemic forms. Enantiomeric excess was evaluated using optical purity test and integrated peak area to describe the enantiomeric ratio. Thermodynamics of chromatographic separation, enthalpy, and entropy were evaluated using the Van't Hoff equation. The proposed methods were found to be selective for identification and determination of the eutomer in drug substances and products.
Simple, smart and sensitive normal fluorescence and stability-indicating derivative synchronous spectrofluorimetric methods have been developed and validated for the determination of gliquidone in ...the drug substance and drug product. Normal spectrofluorimetric method of gliquidone was established in methanol at λ excitation 225nm and λ emission 400nm in concentration range 0.2–3μg/ml with LOD equal 0.028. The fluorescence quantum yield of gliquidone was calculated using quinine sulfate as a reference and found to be 0.542. Stability-indicating first and third derivative synchronous fluorescence spectroscopy were successfully utilized to overcome the overlapped spectra in normal fluorescence of gliquidone and its alkaline degradation product. Derivative synchronous methods are based on using the synchronous fluorescence of gliquidone and its degradation product in methanol at Δ λ50nm. Peak amplitude in the first derivative of synchronous fluorescence spectra was measured at 309nm where degradation product showed zero-crossing without interference. The peak amplitudes in the third derivative of synchronous fluorescence spectra, peak to trough were measured at 316,329nm where degradation product showed zero-crossing. The different experimental parameters affecting the normal and synchronous fluorescence intensity of gliquidone were studied and optimized. Moreover, the cited methods have been validated as per ICH guidelines. The peak amplitude-concentration plots of the derivative synchronous fluorescence were linear over the concentration range 0.05–2μg/ml for gliquidone. Limits of detection were 0.020 and 0.022 in first and third derivative synchronous spectra, respectively. The adopted methods were successfully applied to commercial tablets and the results demonstrated that the derivative synchronous fluorescence spectroscopy is a powerful stability-indicating method, suitable for routine use with a short analysis time. Statistical comparison between the results obtained by normal fluorescence and derivative synchronous methods and the official one using student's t-test and F-ratio showed no significant difference regarding accuracy and precision.
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•Gliquidone exhibits a normal fluorescence at λ ex. 225nm and λ em. 400nm.•SFS reduces the degree of overlapping of gliquidone and degradation products.•1DSFS, 3DSFS resolves the overlapped spectra of gliquidone and degradates.•The cited methods used for the analysis of drug substance and products•DSFS proved to be stability-indicating methods for gliquidone in presence of degradates.
