scholarly journals Kinetic and Conventional Spectrophotometric Determination of Bumadizone in its Tablets via Oxidative Coupling with 3-Methyl-2-Benzothiazolinone Hydrazone

2009 ◽  
Vol 5 (3) ◽  
pp. 839-854
Author(s):  
Mohamed Walash ◽  
Fathalla Belal ◽  
Manar Tolba ◽  
Mohamed Halawa
Keyword(s):  
Oxidative Coupling ◽  
Coupling Reaction ◽  
Comparison Method ◽  
Spectrophotometric Methods ◽  
Oxidative Coupling Reaction ◽  
Bulk Drug ◽  
Kinetic Spectrophotometric ◽  
Chloride Method ◽  
Good Agreement

Two simple, sensitive and accurate spectrophotometric methods have been developed for the determination of bumadizone in bulk drug and its tablets. Both methods based on the oxidative coupling reaction with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) and measuring the absorbance of the developed colors by direct or kinetic spectrophotometric method. Upon treatment of a mixture of the chromogenic reagent and drug with cerium (IV) ammonium sulfate (method I) or ferric chloride (method I), a red or violet color was developed immediately or after 30 minutes measurable at 557 nm for method I or II, respectively. The absorbance-concentration plots were rectilinear over the ranges of 1-10 μg/mL (r = 0.9999) for method I and 2-16 μg/mL (r = 0.9998) for method II. The detection limits were  0.15 and 0.27 μg/mL & the quantitation limits were 0.46 and 0.84 μg/mL for methods I and II, respectively. Different experimental parameters affecting the development and stability of the reactions products were studied and optimized. The proposed methods were applied successfully to the determination of bumadizone in its tablets, and the results obtained were in good agreement with those obtained using a comparison  method. 

scholarly journals Spectrophotometric Methods for the Assay of Pyrilamine Maleate Using Chromogenic Reagents

2010 ◽  
Vol 7 (4) ◽  
pp. 1507-1513 ◽  
Author(s):  
V. Annapurna ◽  
G. Jyothi ◽  
V. Nagalakshmi ◽  
B. B. V. Sailaja
Keyword(s):  
Charge Transfer ◽  
Oxidative Coupling ◽  
Coupling Reaction ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Method Of Least Squares ◽  
Spectrophotometric Methods ◽  
Oxidative Coupling Reaction ◽  
Charge Transfer Complexation

Simple, accurate and reproducible UV spectrophotometric methods were established for the assay of pyrilamine maleate (PYRA) based on the formation of oxidative coupling and precipitation, charge transfer complexation products. Method A includes the oxidative coupling reaction of PYRA with 3-methyl-2-benzathiazolinone hydrazone (MBTH) in presence of Ce(IV). The formation of oxidative coupling product with 4-amino phenazone (4-AP) in presence of K3Fe(CN)6is incorporated in method B. Precipitation/charge transfer complex formation of the PYRA with tannic acid (TA)/Metol-Cr(VI) in method C were proposed. The optical characteristics such as Beers law limits, molar absorptivity and Sandell’s sensitivity for the methods (A-C) are given. Regression analysis using the method of least squares was made to evaluate the slope (b), intercept (a) and correlation coefficient (r) and standard error of estimation (Se) for each system. Determination of pyrilamine in bulk form and in pharmaceutical formulations were also incorporated.

Spectrophotometric determination of Drug Clonazepam in Pure form and Pharmaceutical Tablets by Oxidative Coupling Reaction with Chlorpromazine hydrochloride

2019 ◽  
Vol 10 (02) ◽  
Author(s):  
Nahlah Salman Saddam ◽  
K H Kadhim
Keyword(s):  
Oxidative Coupling ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Pure Form ◽  
Chlorpromazine Hydrochloride ◽  
Pharmaceutical Tablets ◽  
Spectrophotometric Methods ◽  
Oxidative Coupling Reaction ◽  
Quantification Limit

Sensitive, simple and a Precise spectrophotometric methods were development for the estimation reduced clonazepam (CZP) in purity form and in the pharmaceutical tablets from through using potassium bromate as oxidizing reagent for the drug and Chlorpromazine Hydrochloride (CPZ.HCL) as new chromogenic reagent. That led to forms colored products with a maximum absorbance of 530 nm. For the conditions reaction have been studied and optimized. The linearity range for Clonazepam was 0.05–3.5 μg/ ml, while the detections limit 0.0061 and the quantification limit 0.020 μg ml-1. The Molar Absorptivity 1.381×104 L/ mol cm with Shandell's sensitivity 0.0228 μg. cm-2. Finally the proposed methods were successfully Appling for estimation CZP in pure form and commercial formulations.

NEW SPECTROPHOTOMETRIC METHODS FOR THE QUANTITATIVE ESTIMATION OF ELETRIPTAN IN DRUG FORMULATION

INDIAN DRUGS ◽  
2014 ◽  
Vol 51 (01) ◽  
pp. 18-26
Author(s):  
N Usha Rani ◽  
◽  
R. Sreenivasa Rao ◽  
K. Saraswathi
Keyword(s):  
Oxidative Coupling ◽  
Quantitative Estimation ◽  
Coupling Reaction ◽  
Pharmaceutical Formulations ◽  
Drug Formulation ◽  
Reagent Blank ◽  
Colored Complex ◽  
Spectrophotometric Methods ◽  
Oxidative Coupling Reaction ◽  
Bulk Drug

Five simple, accurate, sensitive and economical UV spectrophotometric methods has been developed and subsequently validated for the determination of eletriptan in bulk and pharmaceutical formulations. The methods were based on the formulation of colored complex of eletriptan with different reagents. Absorbance of the formed color complex is measured against the reagent blank at the wavelength of maximum absorbance. In this paper, five spectrophotometric methods were proposed. Method A is based on the formation of oxidative coupling reaction involving the use of iron (III) – MBTH (3-methyl-2-benzo thiazolinone hydrazone hydrochloride). The resulting green colored chromogen complex absorbs at λmax = 520 nm. Reaction of eletriptan with ferric chloride and K3 [Fe (CN)6 ] to form a green colored species having absorption maxima at λmax =790 nm is used in Method B. Method C is based on the reaction eletriptan with FeCl3 and 1,10 phenanthroline to form a blood red colored chromogen, exhibiting absorption at λmax = 620 nm. Formation of oxidative coupling of drug with brucine in the presence of sodium meta periodate to form a purple red colored species is used in Method D which exhibits absorption maxima at λmax = 520 nm. Method E is based on the formation of complex with acidic dye WF BBL having absorption maxima at λmax = 610 nm. All these methods have different linearity ranges. Statistical analysis proves that the proposed methods are reproducible and selective for the estimation of eletriptan in bulk drug and in its tablet dosage form.

scholarly journals Indirect spectrophotometric Indirect spectrophotometric determination of chlordiazepoxide in pharmaceutical formulations via oxidative coupling reaction with phenothiazine

2018 ◽  
pp. 7-14
Author(s):  
Hind Hadi ◽  
Mariam Jamal
Keyword(s):  
Oxidative Coupling ◽  
Coupling Reaction ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Calibration Plot ◽  
Pharmaceutical Dosage Forms ◽  
Oxidative Coupling Reaction ◽  
Formed Product

Abstract A sensitive, precise and reliable indirect spectrophotometric method for the determination of chlordiazepoxide (CDE) in pure and pharmaceutical dosage forms is described. The method is based on oxidative coupling reaction between amino group resulting from acidic decomposition of CDE with phenothiazine in the presence of sodium periodate to produce an intense green soluble dye that is stable and shows a maximum absorption at 602 nm. The calibration plot indicates that Beer’s law is obeyed over the concentration range of 0.1?50 µg/mL, with a molar absorptivity of 1×104 L/mol cm and correlation coefficient of 0.9994.All the conditions that affecting on the stability and sensitivity of the formed product were studied and optimized and the suggested method was effectively applied for the determination of CDE in commercial dosage forms.

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