Spectrophotometric determination of gliclazide in pharmaceuticals and biological fluids through ternary complex formation with eosin and palladium (II)

Development of Eco-Friendly Scattering and Fluorimetric Methods for the Determination of Clemastine Through Its Interaction with Eosin Y: Assessment of Whiteness, Blueness, and Greenness Tools

For the first time, clemastine was estimated in this work utilizing two validated resonance Rayleigh scattering (RRS) and fluorimetric methods. The methods relied on forming an association complex in an acidic medium between eosin Y reagent and clemastine. In the spectrofluorimetric approach, the investigated drug was quantified by quenching the fluorescence-emission intensity of eosin Y at 543.5 nm. The RRS method relied on enhancing the RRS spectrum at 331.8 nm, which is produced when eosin Y interacts with clemastine. Suitable conditions were established for the reaction to achieve maximum sensitivity. The linear values obtained from the spectrofluorimetric approach and the RRS method fall into the ranges of 0.2-1.5 µg mL- 1 and 0.25-2.0 µg mL- 1, respectively. It was established that the detection limits for these methods were 0.045 µg mL- 1 and 0.059 µg mL- 1, respectively. The developed methodologies yielded acceptable recoveries when used to estimate the quantity of clemastine in its pharmaceutical tablet dosage form. Regarding the use of greener solvents that were chosen, the suggested and reported methods were compared with the help of the Green Solvents Selecting (GSST) tool for assessing hazardous solvents to achieve sustainability. Furthermore, analytical Eco scale and comprehensive assessments of whiteness, blueness, and greenness were carried out utilizing Modified NEMI, ComplexGAPI, and AGREE evaluation tools. Additionally, recently developed tools such as BAGI and RGB 12 were applied to assess the blueness and the whiteness of the suggested methods.

Application of sulfur and nitrogen doped carbon quantum dots as sensitive fluorescent nanosensors for the determination of saxagliptin and gliclazide

In this study, highly fluorescent sulfur and nitrogen doped carbon quantum dots (S,N-CQDs) were used as fluorescent nanosensors for direct spectrofluorimetric estimation of each of gliclazide (GLZ) and saxagliptin (SXG) without any pre-derivatization steps for the first time. S,N-CQDs were synthesized employing a simple hydrothermal technique using citric acid and thiosemicarbazide. The produced S,N-CQDs were characterized using different techniques including fluorescence emission spectroscopy, UV spectrophotometry, high-resolution transmission electron microscopy and FT-IR spectroscopy. Following excitation at 360 nm, S,N-CQDs exhibited a strong emission peak at 430 nm. The native fluorescence of S,N-CQDs was quantitatively enhanced by addition of increased concentrations of the studied drugs. The fluorescence enhancement of S,N-CQDs and the concentrations of the studied drugs revealed a wide linear relationship in the range of 30.0-500.0 µM and 75.0-600.0 µM with limits of detection of 5.0 and 10.15 µM for GLZ and SXG, respectively. The proposed method was efficiently used for determination of cited drugs in their commercial tablets with % recoveries ranging from 98.6% to 101.2% and low % relative standard deviation values (less than 2%). The mechanism of interaction between S,N-CQDs and the two drugs was studied. Validation of the proposed method was carried out in accordance with International Conference on Harmonization (ICH) guidelines.

Facile approaches for determination of Bromhexine Hydrochloride and its active metabolite Ambroxol Hydrochloride using Eosin Y

New validated Spectroscopic methods were developed to assay bromhexine hydrochloride and its active metabolite ambroxol hydrochloride separately in pure form and pharmaceutical formulations. The spectrophotometric assay (Method I) shows complex formation between each of the drugs and eosin Y at 540 nm at pH 3.6 and 3.4 ml of 4x10-4M Eosin for bromhexine and ambroxol. The Spectrofluorimetric assay (Method II) depends on quenching eosin native fluorescence by the studied drugs, which measured at 540 nm after excitation at 302 nm. The spectrophotometric absorbance-concentration plot is rectilinear over the ranges (1.0-5.0) and (1.0-10.0) μg/ml for bromhexine and ambroxol with LOD of 0.31 and 0.14 μg/ml and LOQ of 0.94 and 0.42 μg/ml for the two drugs respectively. The fluorometric-concentration plot is linear along the range (1.0-5.0) μg/ml and (1-10) μg/ml for the two drugs respectively with LOD of 0.13 μg/ml and 0.22 μg/ml and LOQ of 0.4 μg/ml and 0.65 μg/ml for the two drugs respectively. Developed assays have been validated in agreement with ICH recommendations and they were used in the analysis of commercial drug formulations containing the two mucolytic drugs and the results were matching with those obtained by the comparison method.

Utilization of a complex arrangement approach for spectroscopic examination with Eosin Y of various cephalosporins in their pure or pharmaceutical dosage forms, and in human plasma

Approved, basic, effective and successful spectroscopic strategies (spectrophotometric and spectrofluorimetric) were created to measure seven cephalosporins: cefpiramide (I), cefuroxime (II), cefoxitin (III), ceftazidime (IV), cefpirome (V), ceftobiprole (VI), and ceftriaxone (VII). These strategies used a two-fold complex arrangement response for the drug amino groups with Eosin Y (EY). The examined drugs were determined spectrophotometrically at 542-550 nm in acetic acid derivative buffer. The examined drugs were determined spectrofluorimetrically by measuring their quenching effect on EY local fluorescence at 545 nm after excitation at 305 nm. The absorbance-intensity plots were rectilinear over the ranges 20-100, 10-130, 20-220, 30-230, 10-210, 20-180 and 10-130 μg ml^-1 for I, II, III, IV, V, VI, and VII samples, respectively. The fluorescence-intensity plots were rectilinear over the ranges 0.5-1.5, 0.1-0.9, 0.3-1.5, 0.5-2.5, 0.1-0.9, 0.5-2.5 and 0.1-1.0 μg ml^-1 for I, II, III, IV, V, VI, and VII samples, respectively. The recommended materials were certified as adhering to International Council for Harmonisation (ICH) guidelines and were used to examine the tested drugs in different dosage forms and in human plasma tests. The approved materials matched the reference materials.

Novel spectrofluorimetric determination of brigatinib in bulk powder and human urine samples via ion-pair complex formation using eosin Y

The developed spectrofluorimetric method was successfully applied to the analysis of brigatinib (BRG) in its bulk powder form, and human urine sample. It is based on the investigation of the fluorescence spectrum behavior of the BRG-eosin Y complex. The relative fluorescence intensity (RFI) was recorded at 560 nm after excitation at 480 nm. The principle of the proposed method was thoroughly explained. All experimental parameters affecting method development were optimized. Moreover, the obtained results were fully discussed and statistically analyzed. The molar ratio method was applied to study the stoichiometric relationship between BRG and eosin Y complex. The method revealed a ratio of 1:3 for BRG-eosin Y afforded the highest RFI. The developed method was validated over the concentration range of 62.5-4000 ng mL^-1. The results were compared positively with the reported method.

Studying the association complex formation of atomoxetine and fluvoxamine with eosin Y and its application in their fluorimetric determination

A simple, sensitive and non-extractive spectrofluorimetric method has been developed and validated for the determination of two psychoanaleptic drugs, atomoxetine and fluvoxamine, in pure forms and pharmaceutical dosage forms. The proposed method is based on the formation of binary complexes between eosin Y and the studied drugs in the presence of a Teorell-Stenhagen buffer. The quenching of the native fluorescence of eosin Y due to complex formation with the studied drugs was measured spectrofluorimetrically at 545 nm after excitation at 302 nm. At the optimum reaction conditions, the fluorescence quenching values (ΔF) and concentrations were rectilinear over the concentration ranges of 0.2-2.2 and 0.3-2.2 µg ml^-1 for atomoxetine and fluvoxamine, respectively. The developed method was successfully applied for the determination of the studied drugs in their pharmaceutical formulations with average percentage recoveries of 100.13 ± 0.66 and 99.69 ± 0.44 for atomoxetine and fluvoxamine, respectively (n = 5), without interference from common excipients.

Resonance Rayleigh scattering and resonance nonlinear scattering methods for the determination of nicardipine hydrochloride using eosin Y as a probe

A novel, highly sensitive, simple and quick method to determine nicardipine hydrochloride by RRS, SOS and FDS were established.

Supramolecular Interaction of Gliclazide with Cucurbit[7]uril and its Analytical Application

Gliclazide (GLZ) is non-fluorescent in aqueous solution. This property makes its determination through direct fluorescent methods impossible. Palmatine (PAL) exhibits very weak fluorescence emissions in aqueous solution. However, in acidic media at room temperature, PAL can react with cucurbit[7]uril (CB[7]) to form a stable complex and the fluorescence intensity of the complex is greatly enhanced. Dramatic quenching of the fluorescence intensity of the CB[7]–PAL complex was observed with the addition of GLZ. The competing reactions and the supramolecular interaction mechanisms between GLZ and PAL as they fight for occupancy of the CB[7] cavity were studied using spectrofluorimetry, 1H NMR spectroscopy, and molecular modelling calculations. The association constants of the complexes formed between the host and the guest were determined. Based on the significant quenching of the supramolecular complex fluorescence intensity, a fluorescent probe method of high sensitivity was developed to determine GLZ in its pharmaceutical dosage forms and in human plasma with good precision and accuracy. The linear range of the method was from 0.003 to 2.100 μg mL–1. The limit of detection was 0.001 μg mL–1. This shows that the proposed method has promising potential for therapeutic monitoring and pharmacokinetics and for clinical application.

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). Under the optimum conditions, the binary complex showed absorption maxima at 545 nm for tizanidine and 542 nm for orphenadrine. The calibration plots were rectilinear over concentration range of 0.5-8 μg/mL and 1-12 μg/mL with limits of detection of 0.1 μg/mL and 0.3 μg/mL for tizanidine and orphenadrine respectively. The different experimental parameters affecting the development and stability of the complex were studied and optimized. The method was successfully applied for determination of the studied drugs in their dosage forms; and to the content uniformity test of tizanidine in tablets.

A supercritical fluid chromatography/tandem mass spectrometry method for the simultaneous quantification of metformin and gliclazide in human plasma

Present study reports the development and validation of a simultaneous estimation of metformin and gliclazide in human plasma using supercritical fluid chromatography followed by tandem mass spectrometry. Acetonitrile:water (80:20) mixture was used as a mobile phase along with liquid CO₂ in supercritical fluid chromatography and phenformin as an internal standard. The modified plasma samples were analyzed by electro-spray ionization method in selective reaction monitoring mode in tandem mass spectrometry. Supercritical fluid chromatographic separation was performed using nucleosil C₁₈ containing column as a stationary phase. The separated products were identified by characteristic peaks and specific fragments peaks in tandem mass spectrometry as m/z 130 to 86 for metformin, m/z 324 to 110 for gliclazide and m/z 206 to 105 for phenformin. The present method was found linear in the concentration ranges of 6.0-3550 ng/ml and 7.5-7500 ng/ml for metformin and gliclazide, respectively. Pharmacokinetic study was performed after an oral administration of dispersible tablets containing 500 mg of metformin and 80 mg of gliclazide using same techniques.

Comparison of ultraviolet detection, evaporative light scattering detection and charged aerosol detection methods for liquid-chromatographic determination of anti-diabetic drugs

Recently, charged aerosol detection (CAD), a new kind of universal detection method, has been widely employed in the HPLC system. In the present study, four kinds of anti-diabetic drug standards, glipizide, gliclazide, glibenclamide and glimepiride were determined by ultraviolet (UV) detection, evaporative light scattering detection (ELSD) and the aforementioned CAD. The results were compared with reference to linearity, accuracy, precision and limit of detection (LOD). All of the experiments were performed on a reverse phase column with water and acetonitrile as the mobile phase. Separations were achieved under the same chromatographic conditions for each detection method. As a result, CAD generated nearly uniform responses compared with UV detection and ELSD. It showed the best accuracy and LOD among 3 detectors and had similar precision with UV detection at higher concentrations while UV detection showed a better precision at lower concentrations than did CAD or ELSD. The LOD of CAD, in fact, can be up to two times higher than that of ELSD. The UV and ELSD linearity was satisfactory at R(2)>0.99, though in the case of CAD, a log-log transformation was needed. The proposed methods were also applied to the real anti-diabetic drugs and diabetes-related dietary supplements.

Trace analysis of glyclazide in human plasma at microscale level by mass spectrometry

Green (reagents and organic solvents saving) analytical chemistry is a new strategy for pharmaceutical analysis. The principles of this idea include primary elimination or at least reduction of the amounts of organic reagents and solvents. In this study, we have provided two simple methods for the analysis of clinical drugs in human plasma. One is the capillary LC (Cap LC) connected to MS-MS, the other is the matrix-assisted laser desorption ionization (MALDI) connected to TOF MS. Sulfonylurea drugs are usually used in diabetes mellitus patients. Diabetes is a syndrome of disordered metabolism resulting in abnormally high blood sugar levels (hyperglycemia). These microscale methods were successfully applied for the monitoring of drug levels in human plasma using gliclazide (a second-generation sulfonylurea) as the test platform. The sensitivity of these methods is sufficient for detecting the gliclazide within a therapeutic range. All the analytical procedures (including human plasma, sample preparation, and flow rate of the analytical system) were at microscale level. These two methods would lower the consumption of organic solvents further safeguarding our environment.

Spectrophotometric determination of carbinoxamine maleate in pharmaceutical formulations by ternary complex formation with Cu(II) and eosin

A simple and sensitive spectrophotometric method was developed for the determination of carbinoxamine maleate in pharmaceutical formulations. The method is based on the formation of a ternary complex, extractable with chloroform, between copper(II), eosin, and carbinoxamine maleate. The absorption spectra of the ternary complexes shows, under optimum conditions, a maxima at 538 nm, with apparent molar absorptive 6.1690 x 10(4) mol(-1) cm(-1), Sandell's sensitives 6.75 x 10(-3) microg cm(-2), and linearity in the concentration range 0.75-10.0 microg ml(-1). The method can be achieved with high accuracy (recovery values, 100 +/- 2%) and precision (with standard deviation 0.029-0.155 and relative standard deviation 3.87-1.55%). The method was again successfully applied, with high accuracy and good precision, for the determination of carbinoxamine maleate in various pharmaceutical formulations (syrup, drops, and tablets).