Investigating fluorogenic labelling of amine coupled with first-order derivative spectrofluorimetry as a versatile analytical methodology: Application to estimation of benoxinate in its eye drops.

In this research, fluorogenic labelling followed by applying first-order derivative spectrofluorimetry for the developed fluorophore is discussed as an alternative, sensitive and selective analytical approach. Benoxinate, containing a primary amine and fluorescamine reagent were selected for the study. Then the proposed methodology relies on the reaction between the primary amine in benoxinate with fluorescamine that selectively reacts with primary amines to develop highly fluorescent products.

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.

Label-free green estimation of atenolol and ivabradine hydrochloride in pharmaceutical and biological matrices by synchronous spectrofluorimetry.

In this work, a label-free, rapid, and sensitive synchronous spectrofluorometric method was implemented to assay atenolol (ATL) and ivabradine hydrochloride (IVB) in pharmaceutical and biological matrices. Simultaneous determination of ATL and IVB by conventional spectrofluorometry cannot be implemented because of the clear overlap of the emmision spectra of ATL and IVB. To overcome this problem, synchronous fluorescence measurements at a constant wavelength difference (Δλ) combined with mathematical derivatization of the zero order spectra were perforemed.

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.

Insights into the spectrofluorometric determination of the neuromuscular blocker mivacurium chloride.

Fluorescence spectroscopy is gaining interest in the analysis and quantitative determination of different drugs. This study was carried out to investigate the fluorometric properties of the short-acting muscle relaxant mivacurium in its pure form, injection, and human plasma. It is nondepolarizing skeletal muscle relaxant for intravenous (IV) administration.

Spectroscopic strategies for quantitation of varenicline in pharmaceutical preparations and content uniformity testing.

Herein, two new facile methods were examined for varenicline determination using erythrosine. The latter is a food additive that has been recently investigated as a fluorescent dye for the determination of drugs. In the first method, the fluorescence of erythrosine B was quenched quantitatively by increasing the concentration of varenicline through ion-pair complex formation.

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.

First-order derivative synchronous spectrofluorimetric determination of two antihypertensive drugs, metolazone and valsartan, in pharmaceutical and biological matrices.

In this study, a facile, rapid, and sensitive spectrofluorimetric method was evolved to analyse two antihypertensive drugs, namely, metolazone (MTZ) and valsartan (VST), in pharmaceutical and biological matrices. Both analytes exhibited intrinsic fluorescence activities which were significantly affected by environmental factors such as pH and solvent systems. However, simultaneous determination of MTZ and VST by conventional spectrofluorometry cannot be achieved simply because of the strong overlap between their fluorescence spectra.

Synchronized spectrofluorimetric determination of ponatinib and curcumin as an effective therapeutic combination in laboratory prepared mixtures and human plasma samples.

Curcumin is a natural product that is frequently utilized in cancer prevention and treatment. The significant benefit of vegetable-derived nutraceuticals in combination with widespread cytostatic medication such as ponatinib is to reduce toxicity and side effects. In this paper, we focus the study on analytical quantification of ponatinib and curcumin through highly sensitive synchronous spectrofluorometric method.

Investigation of the fluorescence of benoxinate for facile determination in pure form, eye drops and aqueous humor.

A new approach to determine the local anesthetic benoxinate spectrofluorimetrically was developed. It was found that benoxinate exhibits strong native fluorescence in ethanol at 371 nm after excitation at 297 nm. There was a linear response between the fluorescence intensity and the concentration of the studied drug over the range of 10.

Two validated spectrofluorimeteric and high performance liquid chromatography (HPLC) methods with fluorescence detection for the analysis of a new anti-hepatitis C drug, daclatasvir hydrochloride, in raw material or tablet form and in biological fluids.

Two sensitive and accurate methods have been developed for the estimation of daclatasvir (DAC) in its raw material, dosage form and in biological fluids. Method I is based on the measurement of DAC native fluorescence in methanol at 385 nm after excitation at 315 nm. The relationship between fluorescence intensity and concentration was found to be rectilinear over the linearity range (3.