CHARGE TRANSFER SPECTROPHOTOMETRIC METHODS FOR THE DETERMINATION OF TWO ANTIHISTAMINIC DRUGS IN PHARMACEUTICAL FORMULATIONS

Objective: Simple, accurate and precise spectrophotometric methods have been developed for the determination of two antihistaminic drugs (desloratadine (DES) and ebastine (EBS)) in pure forms and pharmaceutical formulations. Methods: The proposed methods were based on the charge transfer complexation reaction of both drugs as ‘n' electron donor with chloranilic acid (p-CLA) or 2, 3-Dichloro-5,6-dicyano-p-benzoquinone (DDQ) as π acceptors to give highly coloured complex species. The coloured products were quantitated spectrophotometrically at 459 and 460 nm using DDQ and at 532 and 533 nm using p-CLA for DES and EBS, respectively. Optimization of the different experimental conditions were studied. Results: Beer's law was obeyed in the concentration ranges of 5.0-120 and 10-180 mg mL-1 with good correlation coefficients were ≥ 0.9995 and 0.9992 and a relative standard deviation (R.S.D.) of ≤ 0.98 and 1.24% using DDQ and p-CLA methods, respectively. The molar absorptivity, Sandell's sensitivity, detection and quantification limits were also calculated. The developed methods were successfully applied for determination of the studied drugs in pharmaceutical formulations with good accuracy and precision and without interferences from common additives by applying the standard addition technique. Conclusion: The developed methods have been validated statistically for their accuracy, precision, sensitivity, selectivity, robustness and ruggedness as per ICH guidelines and the results compared favorably with those obtained using the reported methods

An efficient ionic liquid-based cloud point extraction to preconcentrate mercury in environmental samples and hair of occupational workers before spectrophotometric detection

ABSTRACT. Mercury preconcentration in environmental samples and hair of occupational workers prior to spectrophotometric detection was described using a unique, eco-friendly, and quick ionic liquid-based cloud point extraction method. The discovered method used an ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate with Triton X-114 as an extracting phase in the presence of a new chelating agent 3-(2-hydroxy-5-ethoxycarbonylphen-1-ylazo)-1,2,4-triazole at pH 7.0 to separate mercury and measure the complex spectrophotometrically at wavelength 550 nm. The effects of several analytical factors on extraction performance were investigated. With a correlation coefficient of 0.9997. The calibration graph was linear in the range of 2.0-400 µg/L. The limit of detection and preconcentration factor, respectively, were 0.5 µg/L and 100. The relative standard deviation of 100 and 300 µg/L mercury (n = 10) was 1.5 and 2.2, respectively, indicating the precision and reliability of the new IL-CPE approach. The accuracy of the proposed approach confirmed through the certified reference materials analysis. The applicability of the established technique was demonstrated successfully by the estimation of trace mercury in environmental samples and hair of occupational workers.     KEY WORDS: Mercury, Ionic liquid-based cloud point extraction, Environmental and hair samples, Spectrophotometry   Bull. Chem. Soc. Ethiop. 2022, 36(4), 767-778.                                                         DOI: https://dx.doi.org/10.4314/bcse.v36i4.

Synthesis, reactions and characterization of 2-methylthionicotino-nitrile, pyrazolopyridine and pyridopyrazolotriazine derivatives

4,6-Diaryl-1H-pyrazolo[3,4-b]pyridin-3-amines 4a-c wereobtained in very pure state and used as the good startingmaterials for the present study. Compound 4a diazotized to give the corresponding diazonium salt 11 and also, reacted with 2-bromo-1-phenylethanone to give the corresponding pyrazolo[3,4-b]pyridin-2-yl)-1-phenylethanone derivative 7 which in turn, used for the preparation of the hydrazone and formamide derivatives 8 and 10 respectively through its reaction with hydrazine hydrate and formic acid respectively. Compound 11 was used for the preparation of pyridopyrazolotriazine derivatives via its coupling with several active –CH2- containing compounds.Considering the data from IR, 1H NMR, the mass spectra and elemental analyses the chemical structures of the newly synthesized heterocyclic compounds were elucidated

Supplementary Material to Design, synthesis and antibacterial activity of new phthalazinedione derivatives

n/

CLOUD POINT EXTRACTION, PRECONCENRATION AND SPECTROPHOTOMETRIC DETERMINATION OF COBALT IN WATER SAMPLES

Objective: A new cloud point extraction (CPE) method was developed for pre concentration of trace cobalt (II) in water samples.Methods: The method is based on the complexation reaction of Co (II) with 2-(benzothiazolyl azo)-4-nitrophenol reagent (BTANP) at pH 7.0 and micelle-mediated extraction using the nonionic surfactant Triton X-114 of the complex.Results: The enriched analyte in the surfactant-rich phase was diluted with methanol and the cobalt content was determined by spectrophotometry at 549 nm. The optimum conditions (e. g. pH, reagent and surfactant concentrations, and temperature and centrifugation times) were evaluated and optimized. The proposed CPE method showed linear calibration within the range 10–300 ng/ml of Co(II) and the limit of detection of the method was 1.5 ng/ml with a pre concentration factor of 50. The relative standard deviation (RSD) was found to be 1.20% (N = 6). The interference effect of some cations and anions was also studied.Conclusion: The proposed method has been successfully applied to the determination of Co(II) in water samples with a recovery from spiked samples in the range of 96.60–98.70%.Â

Bacterial contamination of white coats and hands of healthcare workers at mansoura university children’s hospital, Mansoura-Egypt

Background: Transmission of hospital acquired infections (HAIs) may be associated with contamination of healthcare workers’ (HCWs) hands and white coats.Objective: The purpose of this study was to clarify the role of HCWs’ white coats in transmitting HAIs and to determine the association between bacterial contamination of HCWs’ hands and white coats.Methods: A total of 154 HCWs were enrolled in the study; different samples were taken from their hands and white coats. Samples were processed and both microbiological and biochemical characterization of the isolates were done using standard microbiological protocols.Results: Up to 65.6% of hands and 61% of coats of HCWs were contaminated by microorganisms. Staphylococcus aureus was the most commonly isolated organisms from both hands and coats of HCWs (29.2%, 27.3% respectively) followed by MRSA (22.1%, 24.7% respectively).Conclusions: The risk for contamination of hands and coats of HCWs is high in different clinical settings. In order to reduce the rate of HAIs, a strict dress protocol should be set into play to prevent cross contamination between HCWs and patients.Keywords: contamination, HCWs, coat, hand, Staphylococcus aureus, MRSA. Contamination bacterienne de manteaux blancs et de mains de soins de sante a l'hopital pour enfants de l'universite mansoura, Mansoura-EgypteContexte: La transmission des infectionsObjectif: Le but de cette étude était de déterminer l'étendue, le type et l'association entre la contamination bactérienne des mains des travailleurs de la santé et les blouses blanches.Méthodes: Au total, 154 travailleurs de la santé ont été inclus dans l'étude; différents échantillons ont été pris de leurs mains et des manteaux blancs. Les échantillons ont été traités et la caractérisation microbiologique et biochimique des isolats a été effectuée en utilisant des protocoles microbiologiques standard.Résultats: Jusqu'à 65,6% des mains et 61% des couches de TS ont été contaminées par des micro-organismes. Le Staphylococcus aureus était le plus souvent isolé des deux mains et des deux sexes (29,2%, 27,3%), suivi par le SARM (22,1%, 24,7% respectivement).Conclusions: Le risque de contamination des mains et des couches de TS est élevé dans différents contextes cliniques. Afin de réduire le taux d'IASS, un protocole vestimentaire strict devrait être mis en place pour prévenir la contamination croisée entre les travailleurs de la santé et les patients.Mots clés: contamination, agents de santé, manteau, main, Staphylococcus aureus, SAR

Shapes and Positions of Black Hole Shadows in Accretion Disks and Spin Parameters of Black Holes

Can we determine a spin parameter of a black hole by observation of a black hole shadow in an accretion disk? In order to answer this question, we make a qualitative analysis and a quantitative analysis of a shape and a position of a black hole shadow casted by a rotating black hole on an optically thick accretion disk and its dependence on an angular momentum of a black hole. We have found black hole shadows with a quite similar size and a shape for largely different black hole spin parameters and a same black hole mass. Thus, it is practically difficult to determine a spin parameter of a black hole from a size and a shape of a black hole shadow in an accretion disk. We newly introduce a bisector axis of a black hole shadow named a shadow axis. For a rotating black hole a shape and a position of a black hole shadow are not symmetric with respect to a rotation axis of a black hole shadow. So, in this case the minimum interval between a mass center of a black hole and a shadow axis is finite. An extent of this minimum interval is roughly proportional to a spin parameter of a black hole for a fixed inclination angle between a rotation axis of a black hole and a direction of an observer. In order to measure a spin parameter of a black hole, if a shadow axis is determined observationally, it is crucially important to determine a position of a mass center of a black hole in a region of a black hole shadow.Comment: 13 pages, 6 figures, accepted for publication in Ap

SENSITIVE SPECTROPHOTOMETRIC ASSAY OF MUSCARINIC RECEPTOR ANTAGONIST TOLTERODINE TARTRATE IN BULK DRUG AND PHARMACEUTICAL FORMULATIONS

Objective: Simple, sensitive, and accurate spectrophotometric methods have been developed for the assay of tolterodine tartrate (TOL) in bulk drugand pharmaceutical formulations.Methods: The proposed methods are based on oxidation reaction of TOL with a known excess of cerium(IV) ammonium sulfate as an oxidizing agentin acid medium followed by determination of unreacted oxidant by adding a fixed amount of dye, e.g., amaranth (AM), rhodamine 6G (Rh6G), andindigo carmine (IC) followed by measuring the absorbance at 520, 530, and 610 nm, respectively. The effect of experimental conditions was studiedand optimized.Results: The Beer's law was obeyed in the concentration ranges of 1.0-10, 1.0-12, and 0.5-9.0 μg/mL using AM, Rh6G, and IC dyes, respectively, witha correlation coefficient ≥0.9995. The calculated molar absorptivity values are 1.868×104, 1.008×104, and 1.623×104 L/mol/cm using AM, Rh6G, andIC dyes, respectively. The limits of detection and quantification were reported. Intraday and interday accuracy and precision of the methods have beenevaluated. No interference was observed from the additives.Conclusion: The proposed methods were successfully applied to the assay of TOL in tablets preparations, and the results were statistically comparedwith those of the reported method by applying Student's t-test and F-test. The reliability of the methods was further ascertained by performingrecovery studies using the standard addition method