In-Syringe Vortex-Assisted Liquid-Liquid Microextraction Based on Natural Deep Eutectic Solvent for Simultaneous Determination of the Two Anticancer Polyphenols Chrysin and Resveratrol.

The simultaneous determination of multiple anticancer drugs in combination therapy poses a significant analytical challenge due to their complex nature and low concentrations. In this study, we propose an in-syringe vortex-assisted liquid-liquid microextraction (IS-VA-LLME), based on a green natural deep eutectic solvent (NaDES) for the simultaneous determination of two coadministered anticancer drugs (resveratrol and chrysin) prior to the HPLC-UV analysis, for the first time. The key parameters affecting the extraction efficiency, such as extraction solvent, vortex time, pH, and ionic strength were optimized.

Bimetallic porous Mn/Co oxide nanosheets with efficient oxidase-mimicking activity for the sensitive colorimetric determination of resveratrol in different matrices.

Background: Resveratrol, a natural polyphenol compound used as an ingredient in dietary supplements, and pharmaceuticals, has gained significant attention due to its potential health benefits. However, the accurate and sensitive determination of resveratrol in complex matrices remains a challenge. In this study, we propose the utilization of bimetallic porous Mn/Co oxide nanosheets (MnCoO-NSs) as catalysts for the colorimetric determination of resveratrol.

Promoting the sensitive detection of ethamsylate via a colorimetric sensing platform based on the enhanced oxidase-mimicking activity of ultrathin MnO nanosheets.

In this work, we present a novel colorimetric sensing platform for the sensitive detection of ethamsylate (ETM) usingultrathin MnO nanosheets with enhancedoxidase-mimicking activity. A facile template-free hydrothermal process was applied to synthesize the MnO nanosheets under mild conditions. The nanosheets exhibited oxidase-mimicking activity, facilitating the conversion of TMB into the blue-colored oxTMB in the absence of HO.

Green spectrophotometric and spectrofluorimetric determination of biperiden hydrochloride using erythrosine B sensing probe.

Erythrosine B (EB) is a food colorant antiviral xanthene dye that has many applications as a color additive in pharmaceuticals and cosmetics. Its use as a sensor for spectrofluorimetric and spectrophotometric analysis of amine-based pharmaceuticals renders many advantages because of its availability, low cost, rapid labeling, and high sensitivity. Herein, two fast and sensitive spectrofluorimetric and spectrophotometric methods were established for the estimation of the anti-Parkinson drug, biperiden (BIP) hydrochloride (HCl), in its raw material and tablet forms.

Utility of the food colorant erythrosine B as an effective green probe for quantitation of the anticancer sunitinib. Application to pharmaceutical formulations and human plasma.

Sunitinib is a tyrosine kinase inhibitor used for the treatment of renal cell carcinoma and gastrointestinal stromal tumors. In this study, two spectroscopic methods, spectrofluorometric and spectrophotometric, were utilized to quantify sunitinib in different matrices. In method I, the native fluorescence of erythrosine B was quenched by forming ion-pair complex with increasing quantities of sunitinib.

Turn-off fluorescence of S,N-doped carbon dots for determination of two nitro-containing drugs in dosage forms and human plasma.

This study describes the development of an environmentally-friend optical nanosensor for the rapid spectrofluorimetric assessment of two nitro-compounds, namely nitrofurantoin and dantrolene in their dosage forms and plasma samples. A one-step synthetic technique successfully created very bright water-soluble carbon quantum dots doped with sulfur and nitrogen (S,N-CQDs). Carbon was derived from citric acid, while nitrogen and sulfur were obtained from thiosemicarbazide.

Simultaneous spectrofluorimetic determination of remdesivir and simeprevir in human plasma.

As new infectious mutations of SARS-CoV-2 emerged throughout the world, innovative therapies to counter the virus-altered drug sensitivities were urgently needed. Several antiviral options have been in clinical trials or in compassionate use for the treatment of SARS-CoV-2 infections in an attempt to minimize both clinical severity and viral shedding. Recent research indicated that simeprevir acts synergistically with remdesivir, allowing for a multiple-fold decrease in its effective dose when used at physiologically acceptable concentrations.

First derivative synchronous spectrofluorimetric analysis of bisoprolol fumarate and ivabradine in pharmaceutical and biological matrices. Investigation of the method greenness.

A novel, facile, rapid, and precise synchronous spectrofluorimetric method was evolved for the simultaneous estimation of bisoprolol fumarate and ivabradine in dosage forms and biological fluids. The estimation is based on measuring the first derivative of the synchronous fluorescence spectra of ivabradine and bisoprolol fumarate in ethanol at Δλ = 80 nm. The peak amplitudes are measured at 234.

Thiosemicarbazide functionalized carbon quantum dots as a fluorescent probe for the determination of some oxicams: application to dosage forms and biological fluids.

In this study, highly fluorescent water-soluble nitrogen and sulfur doped carbon quantum dots (N, S-CQDs) were synthesized a one-step hydrothermal process utilizing citric acid as a carbon source and thiosemicarbazide as a sulfur and nitrogen source. The obtained N, S-CQDs exhibited an intense emission band at 415 nm ( = 345 nm). In the presence of either piroxicam, tenoxicam or lornoxicam, the emission band at 415 nm was significantly quenched which might be triggered due to destruction of the surface passivation layer of the N, S-CQDs.

Quantitative analysis of favipiravir and hydroxychloroquine as FDA-approved drugs for treatment of COVID-19 using synchronous spectrofluorimetry: application to pharmaceutical formulations and biological fluids.

Coronavirus disease 2019 (COVID-19) is a contagious viral infection caused by coronavirus 2 (SARS-CoV-2) that causes severe acute respiratory syndrome. It has ravaged several countries and burdened many healthcare systems. As the process of authorizing a novel treatment for human use is extensive and involves multiple phases to obtain safety information and identify potential concerns.

Determination of three antiepileptic drugs in pharmaceutical formulations using microfluidic chips coupled with light-emitting diode induced fluorescence detection.

In this study, a facile, sensitive, and precise lab-on-a-chip electrophoretic method coupled with light-emitting diode induced fluorescence (LED-IF) detection was developed to assay three antiepileptic drugs, namely, vigabatrin, pregabalin, and gabapentin, in pharmaceutical formulations. The analytes were derivatised offline for the first time with fluorescine-5-isothiocyanate (FITC) to yield highly fluorescent derivatives with λ of 490/520nm. The FITC-labelled analytes were injected, separated, and quantitated by a microfluidic electrophoresis device using fluorescence detection.

Stacking-cyclodextrin-microchip electrokinetic chromatographic determination of gabapentinoid drugs in pharmaceutical and biological matrices.

A facile, rapid, and highly sensitive microchip-based electrokinetic chromatographic method was developed for the simultaneous analysis of two gabapentinoid drugs, gabapentin (GPN) and pregabalin (PGN). Both drugs were first reacted with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) via nucleophilic substitution reactions to yield highly fluorescent products with λ 470/540nm. Analyses of both fluorescently labeled compounds were achieved within 200s in a poly(methyl methacrylate) (PMMA) microchip with a 30mm separation channel.

Fast separation and quantification of three anti-glaucoma drugs by high-performance liquid chromatography UV detection.

In this study, a simple and accurate high-performance liquid chromatography method was developed and validated for fast separation of three anti-glaucoma drugs: timolol maleate (TM), brimonidine tartrate (BM), and latanoprost (LP). Separation of the three drugs was achieved in < 6 minutes using a BDS Hypersil phenyl column and a mobile phase consisting of acetonitrile: 25mM phosphate buffer, pH 4.0 (50: 50, v/v) at 1.

Simultaneous determination of floctafenine and its hydrolytic degradation product floctafenic acid using micellar liquid chromatography with applications to tablets and human plasma.

A stability-indicating micellar liquid chromatography (MLC) method was developed and validated for the assay of floctafenine (FLF) in the presence of its degradation product and main metabolite, floctafenic acid (FLA). The analysis was carried out on a CLC Shim-Pack octyl silane (C8) column (150 x 4.6 mm id, 5 microm particle size) using a micellar mobile phase consisting of 0.

A validated HPLC method for the determination of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate (DDB) with fluorescence detection in raw material and pill form: application to an in vitro dissolution test and a content uniformity test.

A simple, sensitive and rapid HPLC method with fluorescence detection for the determination of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate (DDB) in the raw material and pill form was developed. Liquid chromatography was performed on a C18 column (250 × 4.6 mm i.

Simultaneous determination of aliskiren hemifumarate, amlodipine besylate, and hydrochlorothiazide in their triple mixture dosage form by capillary zone electrophoresis.

A novel, specific, reliable, and accurate capillary zone electrophoretic method was developed and validated for the simultaneous determination of aliskiren hemifumarate, amlodipine besylate, and hydrochlorothiazide in their triple mixture dosage form. Separation was carried out in a fused-silica capillary (57.0 cm total length and 50.

Stability-indicating spectrofluorimetric method for determination of itopride hydrochloride in raw material and pharmaceutical formulations.

A simple, sensitive and rapid spectrofluorimetric method for determination of itopride hydrochloride in raw material and tablets has been developed. The proposed method is based on the measurement of the native fluorescence of the drug in water at 363 nm after excitation at 255 nm. The relative fluorescence intensity-concentration plot was rectilinear over the range of 0.

Simultaneous determination of sitagliptin and metformin in pharmaceutical preparations by capillary zone electrophoresis and its application to human plasma analysis.

A novel, quick, reliable and simple capillary zone electrophoresis CZE method was developed and validated for the simultaneous determination of sitagliptin (SG) and metformin (MF) in pharmaceutical preparations. Separation was carried out in fused silica capillary (50.0 cm total length and 43.

Validated spectrophotometric methods for determination of Alendronate sodium in tablets through nucleophilic aromatic substitution reactions.

Background: Alendronate (ALD) is a member of the bisphosphonate family which is used for the treatment of osteoporosis, bone metastasis, Paget's disease, hypocalcaemia associated with malignancy and other conditions that feature bone fragility. ALD is a non-chromophoric compound so its determination by conventional spectrophotometric methods is not possible. So two derivatization reactions were proposed for determination of ALD through the reaction with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and 2,4-dinitrofluorobenzene (DNFB) as chromogenic derivatizing reagents.

Simultaneous determination of sulpiride and mebeverine by HPLC method using fluorescence detection: application to real human plasma.

A new simple, rapid and sensitive reversed-phase liquid chromatographic method was developed and validated for the simultaneous determination of sulpiride (SUL) and mebeverine Hydrochloride (MEB) in the presence of their impurities and degradation products. The separation of these compounds was achieved within 6 min on a 250 mm, 4.6 mm i.

Derivative spectrophotometric analysis of benzophenone (as an impurity) in phenytoin.

Three simple and rapid spectrophotometric methods were developed for detection and trace determination of benzophenone (the main impurity) in phenytoin bulk powder and pharmaceutical formulations. The first method, zero-crossing first derivative spectrophotometry, depends on measuring the first derivative trough values at 257.6 nm for benzophenone.

Synchronous fluorescence spectrofluorimetric method for the simultaneous determination of metoprolol and felodipine in combined pharmaceutical preparation.

A rapid, simple and sensitive synchronous specrtofluorimetric method has been developed for the simultaneous analysis of binary mixture of metoprolol (MTP) and felodipine (FDP). The method is based upon measurement of the synchronous fluorescence intensity of the two drugs at Δλ of 70 nm in aqueous solution. The different experimental parameters affecting the synchronous fluorescence intensities of the two drugs were carefully studied and optimized.

Spectrophotometric determination of certain CNS stimulants in dosage forms and spiked human urine via derivatization with 2,4-Dinitrofluorobenzene.

A new spectrophotometric method is developed for the determination of phenylpropanolamine HCl (PPA), ephedrine HCl (EPH) and pseudoephedrine HCl (PSE) in pharmaceutical preparations and spiked human urine. The method involved heat-catalyzed derivatization of the three drugs with 2,4-dinitrofluorobenzene (DNFB) producing a yellow colored product peaking at 370 nm for PPA and 380 nm for EPH and PSE, respectively.The absorbance concentration plots were rectilinear over the range of 2-20 for PPA and 1-14 μg/mL for both of EPH and PSE, respectively.

Development and validation of stability indicating method for determination of sertraline following ICH guidlines and its determination in pharmaceuticals and biological fluids.

Background: Sertraline is a well known antidepressant drug which belongs to a class called selective serotonin reuptake inhibitor. Most published methods do not enable studying the stability of this drug in different stress conditions.

Results: Two new methods were developed for the determination of sertraline (SER).

Spectrophotometric determination of tizanidine and orphenadrine via ion pair complex formation using eosin Y.

A simple, sensitive and rapid spectrophotometric method was developed and validated for the determination of two skeletal muscle relaxants namely, tizanidine hydrochloride (I) and orphenadrine citrate (II) in pharmaceutical formulations. The proposed method is based on the formation of a binary complex between the studied drugs and eosin Y in aqueous buffered medium (pH 3.5).