Sensitive and Selective Extractive Spectrophotometric Method for the Determination of Hydroxyzine Dihydrochloride in Pharmaceuticals 233 Sensitive and Selective Extractive Spectrophotometric Method for the Determination of Hydroxyzine Dihydrochloride in P

Abstract. Hydroxyzine dihydrochloride (HDH), a piperazine H 1 -receptor antagonist and antihistamine, is a rapid acting anxiolytic used principally as an anti-emetic. A sensitive, selective, and precise and accurate spectrophotometric method based on the formation of an ion-pair with orange II (ORG II) as ion-pair complexing agent was developed and validated for the determination of HDH in pharmaceuticals. The chloroform-extractable ion-pair complex exhibited an absorption maximum at 480 nm. Optimization of different experimental conditions is described. Beer's law is obeyed in the range of 1.5-15 µg mL -1 with an apparent molar absorptivity value of 2.07 × 10 4 L mol -1 cm -1 and Sandell's sensitivity value of 0.0216 µg cm -2 . The limit of detection (LOD) and limit of quantification (LOQ) are 0.14 and 0.41 µg mL -1 , respectively. A Job's plot of absorbance versus molar ratio of HDH to ORG II indicated (1:2) stoichiometric ratio. Within-and between-day relative standard deviations at three different concentration levels were < 3%. The developed method was successfully applied to commercial tablets. The results obtained were in good agreement with those obtained using the official method. No interference was encountered from co-formulated substances. Recoveries were 96-109 %. Keywords: Spectrophotometry, hydroxyzine, orange II, pharmaceuticals. Resumen. El dihidrocloruro de hidroxicina (HDH), una piperazina antagonista del receptor H 1 y un antihistamínico, es un ansiolítico de acción rápida usado principalmente como anti-emético. Se desarrolló y validó un método espectrofotométrico sensible, selectivo, preciso y exacto basado en la formación de un par iónico con naranja II (ORG II) como un agente complejante para la determinación de HDH en productos farmacéuticos. El par iónico extraído en cloroformo exhibió un máximo de absorción a 480 nm. Se describió la optimización de las diferentes condiciones experimentales. La ley de Beer se obedeció en el intervalo de 1.5-15 µg mL -1 con un valor de absortividad molar aparente de 2.07 × 10 4 L mol -1 cm -1 y un valor de sensibilidad de Sandell de 0.0216 µg cm -2 . El límite de detección (LD) y el límite de cuantificación (LC) son 0.14 y 0.41 µg mL -1 , respectivamente. Una gráfica de Job de absorbancia versus relación molar de HDH y ORG II indicó una relación estequiométrica (1:2). Las desviaciones estándar relativas dentro y entre días, a tres diferentes niveles de concentración, fueron < 3%. El método desarrollado fue aplicado exitosamente a tabletas comerciales. Los resultados obtenidos estuvieron en buena concordancia con los obtenidos con el método oficial. No se encontró ninguna interferencia de parte de las sustancias de la formulación. Las recuperaciones fueron de 96-109 %

Molecular mechanistic vision on binding interaction of triptan drug, a serotonin (5-HT1) agonist with human serum albumin through multispectral and computational assessments

The triptan drug such as eletriptan in combination with hydrochloride (ETP) is a 5-HT1 receptor agonist used to treat the migraine headache. Human serum albumin (HSA), the fundamental serum protein, executes various functions, that includes transporting and binding of many ligands. HSA binding interaction with ETP is elucidated from molecular docking in composite with fluorescence (emission, 3D and synchronous), UV-vis and FT-IR spectroscopy at 296, 304 and 312 K (pH = 7.40). ETP after interaction modified the HSA secondary structure and its micro-environments. Energy transfer and thermodynamic parameters were evaluated. Various quenching and binding constants were computed for formed ETP-HSA complex. The dominant interactive forces for ETP and HSA binding are hydrogen bonds join up with van der Waals extent possibly at site III (IB). The presence of Ca2+, Co2+, Na+, Mg2+ and Fe3+ ions significantly affected binding ability of ETP towards HSA. The essentialness of this investigation is beneficial in life sciences, medicinal chemistry, pharmaceutical industry and clinical medicine

Spectrophotometric Estimation of Nitrazepam in Pure and in Pharmaceutical Preparations

ree simple, sensitive, accurate, and rapid visible spectrophotometric methods (A, B, and C) have been developed for the estimation of nitrazepam in both pure and in pharmaceutical preparations. ey are based on the diazotization of reduced nitrazepam with nitrous acid followed by coupling with acetyl acetone (method A), diphenylamine (method B), and citrazinic acid (method C) to form colored azo-dyes, exhibiting absorption maxima ( max ) at 400, 550, and 460 nm, for methods A, B, and C, respectively. e produced colored azo-dyes are stable for more than 2 h. Beer's law was obeyed in the concentration range of 0.5-20, 0.3-14 and 0.5-12 g/mL for methods A, B, and C, respectively and the corresponding molar absorptivity values are 1.01 × 10 4 , 1.00 × 10 4 , and 1.51 × 10 4 L mol −1 cm −1 . All variables have been optimized and the results were statistically compared with those of a literature method by employing the Student's t-test and F-test. No interference was observed from common adjuvants normally added to the tablets. e results obtained in the proposed methods are in good agreement with labeled amounts, when marketed pharmaceutical preparations are analyzed, which could be applied in the routine quality control analysis laboratory

Synthesis, Spectral Characterization, in vitro Antimicrobial and Anthelmintic Evaluations of Cu(II) Complexes with a New Schiff Base

Novel Schiff base ligand (E)-2-((3-(benzyloxypyridinylimino) methyl)-4-bromophenol (HL) was synthesized. Using this Schiff base ligand, two new copper(II) complexes, C1 and C2 were prepared. Analytical techniques such as IR, 1H NMR, 13C NMR, mass, UV–visible spectroscopy, molar conductivity, magnetic measurement, ESR and TGA-DTA were used to characterize the ligand HL and its copper complexes. From the ESR spectra, square planar geometry was proposed for C1 and C2. The synthesized ligand, HL along with its copper(II) complexes were subjected to test their in vitro biological efficacies against four bacterial strains Escherichia coli,  Salmonella typhi, Bacillus subtilis and Staphylococcus aureus and two antifungal strains Candida albicans and Aspergillus niger. The results obtained from this work suggest that the studied metal complexes are very effective in biological activities than its ligand. The anthelmintic test of the ligand HL and copper complexes against earthworms, Pheretima posthuma are also investigated. DOI: http://dx.doi.org/10.17807/orbital.v10i7.1168 <br /

Use of the Charge Transfer Reactions for the Spectrophotometric Determination of Risperidone in Pure and in Dosage Forms

The aim of study was to develop and validate two simple, sensitive, and extraction-free spectrophotometric methods for the estimation of risperidone in both pure and pharmaceutical preparations. They are based on the charge transfer complexation reactions between risperidone (RSP) as n-electron donor and p-chloranilic acid (p-CA) in method A and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in method B as π-acceptors. In method A, RSP reacts with p-CA in methanol to produce a bright pink-colored chromogen measured at 530 nm whereas, in method B, RSP reacts with DDQ in dichloromethane to form orange-colored complex with a maximum absorption at 460 nm. Beer's law was obeyed in the concentration range of 0–25 and 0–50 μg/mL with molar absorptivity of and L/moL/cm for RSP in methods A and B, respectively. The effects of variables such as reagents, time, and stability of the charge transfer complexes were investigated to optimize the procedures. The proposed methods have been successfully applied to the determination of RSP in pharmaceutical formulations. Results indicate that the methods are accurate, precise, and reproducible (relative standard deviation %)

Synthesis, characterization, antioxidant, antimicrobial, DNA binding and cleavage studies of mononuclear Cu(II) and Co(II) complexes of 3-hydroxy-N'-(2-hydroxybenzylidene)-2-naphthohydrazide

In this report, we explore the DNA binding properties of mixed ligand copper(II)/cobalt(II) complexes of the type [M(bnp)(phen)H2O].nH2O, and copper(II)/cobalt(II) complexes of the type [M(Hbnp)2], where n=0, 1, ..., H2bnp=3-hydroxy-N'-(2-hydroxybenzylidene)-2-naphtho-hydrazide and phen=1,10-phenanthroline. A host of physical methods like spectral absorption, emission studies and hydrodynamic measurements have been used to probe the effect of ligands on the mode and extent of interaction of the complexes with Calf Thymus DNA. The efficiencies of the complexes to oxidatively cleaved pUC19 DNA was performed in the absence and presence of H2O2. Among the compounds tested for antioxidant capacity, H2bnp displayed excellent activity than its complexes and standards used. It has been observed that Cu(II) and Co(II) complexes exhibited different levels of antibacterial and antifungal effects, with the assays carried out on four pathogenic bacteria and two pathogenic fungi. H2bnp showed moderate activity against bacteria E. coli, X. vesicatoria and fungi, A. niger and A. flavus, but less than its complexes and standard drugs used for assay

Spectrophotometric determination of etamsylate in pharmaceuticals using ferric chloride based on complex formation reactions

The present study describes two simple and selective spectrophotometric methods for the rapid determination of etamsylate (ETM) in bulk and in capsule formulations. The methods are based on the oxidation of ETM with ferric chloride in neutral medium and subsequent chelation of the resulting iron(II) with 1,10-phenanthroline (Phen) (method A) and with 2,2’-bipyridyl (Bipy) (method B). The resulting red colored chromogens are measured at 510 and 520 nm, in method A and B, respectively. In both methods, the absorbance is found to increase linearly with increasing ETM concentration. Beer’s law is obeyed over the ranges 0.5-10 and 0.8-16 µg/ml for method A and B, respectively. The calculated molar absorptivity values are 2.17x104 and 1.65x104 l mol-1 cm-1 for method A and B, respectively, and the corresponding sandell sensitivities are 0.012 and 0.016 µg/cm2. Intra-day and inter-day precision and accuracy of the methods were established according to ICH guidelines. The proposed methods were applied to determine ETM in dosage forms and the results were statistically compared with that of an official BP metho

Benzimidazolyl based Schiff base palladium complex in an ionic liquid: an effective combination for Suzuki coupling

<p>A new benzimidazole based Pd(II) Schiff base complex was prepared and its catalytic activity was evaluated for Suzuki cross-coupling reactions in ethyl-methyl imidazolium hexafluorophosphate [EMIM PF₆] ionic liquid at ambient temperature. The system provides a stable and reusable method for coupling reactions. Optimization for suitable reaction conditions were studied with respect to the effect of catalyst concentration, effects of additives, solvent and substituents on boronic acid. Good to excellent yields were achieved using a modest amount of the catalyst. The reaction time was less and the yield was more compared to previously reported results. In addition, the catalyst can be easily reused and recycled for six times without much loss in activity; this is an example of sustainable and green methodology.</p

Rapid titrimetric and spectrophotometric determination of ofloxacin in pharmaceuticals using N-bromosuccinimide

One titrimetric and two spectrophotometric methods have been described for the determination of ofloxacin (OFX) in bulk drug and in tablets, employing N-Bromosuccinimide as an analytical reagent. The proposed methods involve the addition of a known excess of NBS to OFX in acid medium, followed by determination of unreacted NBS. In titrimetry, the unreacted NBS is determined iodometrically, and in spectrophotometry, unreacted NBS is determined by reacting with a fixed amount of either indigo carmine (Method A) or metanil yellow (Method B). In all the methods, the amount of NBS reacted corresponds to the amount of OFX. Titrimetry allows the determination of 1-8 mg of OFX and the calculations are based on a 1:5 (OFX:NBS) reaction stoichiometry. In spectrophotometry, Beer's law is obeyed in the concentration ranges 0.5-5.0 µg/mL for method A and 0.3-3.0 µg/mL for method B. The molar absorptivities are calculated to be 5.53x10(4) and 9.24x10(4) L/mol/cm for method A and method B, respectively. The methods developed were applied to the assay of OFX in tablets, and results compared statistically with those of a reference method. The accuracy and reliability of the methods were further ascertained by performing recovery tests via the standard-addition method.<br>Descrevem-se métodos, um titulométrico e dois espectrofotométricos, para a determinação de ofloxacino (OFX) na matéria-prima e em comprimidos, empregando a N-bromossuccinimida (NBS) como reagente analítico. Os métodos propostos envolvem a adição de excesso conhecido de NBS ao OFX, em meio ácido, seguida de determinação do NBS que não reagiu. Na titulometria, o NBS que não reagiu é determinado iodometricamente e na espectrofotometria, o NBS que não reagiu é determinado pela reação com quantidade fixa de índigo carmim (Método A) ou amarelo de metanila (Método B). Em todos os métodos, a quantidade de NBS que reagiu corresponde à quantidade de OFX. A titulometria permite a determinação de 1-8 mg de OFX e os cálculos se baseiam na estequiometria de reação de 1:5 (OFX:NBS). Na espectrofotometria, a Lei de Beer é obedecida nas faixas de concentração de 0,5-5,0 µg/mL, para o método A, e de 0,3-3,0 µg/mL, para o método B, respectivamente. Os métodos desenvolvidos foram aplicados para o teste de OFX em comprimidos e os resultados foram comparados estatisticamente com aqueles do método de referência. A precisão e a confiabilidade dos métodos foram, posteriormente, verificadas por meio dos testes de recuperação via método de adição de padrão