scholarly journals Spectrophotometric Method for the Determination of Carboxin in its Formulations and Environmental Samples

2011 ◽  
Vol 8 (4) ◽  
pp. 1680-1685 ◽  
Author(s):  
C. Swarna ◽  
K. Purushotham Naidu ◽  
G. Nagendrudu ◽  
N. V. S. Naidu ◽  
K. Saraswathi
Keyword(s):  
Oxidative Coupling ◽  
Environmental Samples ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Beer's Law ◽  
Label Claim ◽  
Colored Product ◽  
Beer’S Law ◽  
Good Agreement

Simple, precise, rapid, sensitive and accurate spectrophotometric methods have been developed for the estimation of carboxin in pure form and in its formulations. The first method is based on oxidative coupling of carboxin with 1,10-phenonthrolin in presence of ferric chloride to form orange colored product with λmaxof 510 nm. The product obeyed Beer's law in the concentration range 1-10 mL (10 to 100 µg/mL) with molar absorptivity of 1.1425×103Sandell's sensitivity 0.2061. The second method is based on the reaction of carboxin with 2,2'-bipyridine to form orange red colored product exhibiting λmaxof 522 nm with molar absorptivity, Sandell's sensitivity 2.2605×103, 0.1041 respectively. It obeys Beer's law in the concentration range of 0.5-50 mL (5 to 50 µg/mL). The assay of results was found to be in good agreement with label claim.

scholarly journals Optimization and Validation of Quantitative Spectrophotometric Methods for the Determination of Alfuzosin in Pharmaceutical Formulations

2007 ◽  
Vol 4 (3) ◽  
pp. 397-407 ◽  
Author(s):  
M. Vamsi Krishna ◽  
D. Gowri Sankar
Keyword(s):  
Room Temperature ◽  
Pharmaceutical Formulations ◽  
Good Precision ◽  
Spectrophotometric Methods ◽  
Experimental Parameters ◽  
Beer's Law ◽  
Colored Product ◽  
Beer’S Law ◽  
Control Application

Three accurate, simple and precise spectrophotometric methods for the determination of alfuzosin hydrochloride in bulk drugs and tablets are developed. The first method is based on the reaction of alfuzosin with ninhydrin reagent inN, N'-dimethylformamide medium (DMF) producing a colored product which absorbs maximally at 575 nm. Beer’s law is obeyed in the concentration range 12.5-62.5 µg/mL of alfuzosin. The second method is based on the reaction of drug with ascorbic acid in DMF medium resulting in the formation of a colored product, which absorbs maximally at 530 nm. Beer’s law is obeyed in the concentration 10-50 µg/mL of alfuzosin. The third method is based on the reaction of alfuzosin withp-benzoquinone (PBQ) to form a colored product with λmax at 400 nm. The products of the reaction were stable for 2 h at room temperature. The optimum experimental parameters for the reactions have been studied. The validity of the described procedures was assessed. Statistical analysis of the results has been carried out revealing high accuracy and good precision. The proposed methods could be used for the determination of alfuzosin in pharmaceutical formulations. The procedures were rapid, simple and suitable for quality control application.

scholarly journals 2-Hydroxy-1-naphthaldehyde-P-hydroxybenzoichydrazone: A New Chromogenic Reagent for the Determination of Thorium(IV) and Uranium(VI)

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
V. S. Anasuya Devi ◽  
V. Krishna Reddy
Keyword(s):  
Detection Limit ◽  
Simultaneous Determination ◽  
Uranium Content ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Maximum Absorbance ◽  
Highly Sensitive ◽  
Beer's Law ◽  
Beer’S Law

Simple, sensitive, selective, direct, derivative, and simultaneous spectrophotometric methods are developed for the determination of uranium and thorium individually and simultaneously. The methods are based on the reaction of 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoichydrazone (HNAHBH) with thorium(IV) and uranium(VI). HNAHBH reacts with thorium and uranium at pH 6.0 forming stable yellow and reddish brown coloured complexes, respectively. [Th(IV)-HNAHBH] complex shows maximum absorbance at 415 nm. Beer’s law is obeyed over the concentration range 0.464–6.961 μg mL−1with a detection limit of 0.01 μg mL−1and molar absorptivity,ε, 3.5 × 104 L mol−1 cm−1. Maximum absorbance shown by [U(VI)-HNAHBH] complex is at 410 nm with Beer’s law range 0.476–7.140 μg mL−1, detection limit 0.139 μg mL−1and molar absorptivity,ε, 1.78 × 104 L mol−1 cm−1. Highly sensitive and selective second-order derivative methods are reported for the direct and simultaneous determination of Th(IV) and U(VI) using HNAHBH. The applicability of the developed methods is tested by analyzing water, ore, fertilizer, and gas mantle samples for thorium and uranium content.

scholarly journals Redox-Reaction Based Spectrophotometric Assay of Isoniazid in Pharmaceuticals

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
N. Swamy ◽  
K. N. Prashanth ◽  
K. Basavaiah
Keyword(s):  
Prussian Blue ◽  
Redox Reaction ◽  
Molar Absorptivity ◽  
Spectrophotometric Assay ◽  
Commercial Formulation ◽  
Spectrophotometric Methods ◽  
Ich Guidelines ◽  
Beer's Law ◽  
Beer’S Law

Two spectrophotometric methods are described for the determination of isoniazid (INH) in pharmaceuticals. In the first method (FCR method), INH is reacted with Folin-Ciocalteu reagent in Na2CO3 medium and the resulting blue colored chromogen measured at 760 nm. Iron(II), formed as a result of reaction between INH and iron(III), is made to react with ferricyanide, and the resulting Prussian blue is measured at 760 nm, basing the second method (FFC method). The conditions for better performance are optimized. Beer’s law is obeyed in the concentration ranges 0.5–10 and 0.2–3.0 μg mL−1 for FCR method and FFC methods, respectively, with corresponding molar absorptivity values of 1.12×104 and 4.55×104 L mol−1 cm−1. The methods are validated for accuracy, precision, LOD, LOQ, robustness, and ruggedness as per the current ICH guidelines. The validated methods were successfully applied to quantify INH in its commercial formulation with satisfactory results; hence the methods are suitable for isoniazid determination in bulk drugs and pharmaceuticals.

scholarly journals VALIDATED SPECTROPHOTOMETRIC METHOD TO DETERMINE VARDENAFIL AND SILDENAFIL IN PHARMACEUTICAL FORMS USING POTASSIUM IODIDE AND POTASSIUM IODATE

2017 ◽  
Vol 9 (10) ◽  
pp. 65 ◽  
Author(s):  
Amir Alhaj Sakur ◽  
Shaza Affas
Keyword(s):  
Potassium Iodide ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Potassium Iodate ◽  
Average Recovery ◽  
Beer's Law ◽  
Beer’S Law ◽  
Good Agreement

Objective: To develop and validate simple, sensitive, precise and free of organic solvents method for the determination of sildenafil (SIL) and vardenafil (VAR) in bulk and pharmaceutical formulation.Methods: The method is based on the reaction of studied drugs with a mixture of potassium iodide and potassium iodate in an aqueous medium at (25±2 °C) to form yellow coloured triiodide ions (I3-) within 45 min. The reaction is followed spectrophotometrically by measuring the absorbance at 288, 351 nm and 285, 351 nm for sildenafil and vardenafil respectively.Results: The effects of analytical parameters on the reported systems were investigated. Beer's law of SIL was obeyed in the range of (0.4-12) μg ml-1and (0.6-16) μg ml-1. Molar absorptivity was found to be (67.659 ×103) lmol/cmand (37.955×103) lmol/cm at 288 nm, 351 nm respectively. Beer's law of VAR was obeyed in the range of (0.2-13) μg/mland (0.5-40) μg/ml. Moreover, molar absorptivity’s were found to be (68.719 ×103) l mol-1 cm-1and (26.691×103) l mol-1 cm-1 at 285 nm, 351 nm respectively.Conclusion: The proposed method has been applied to determine the components in dosage forms with an average recovery of 98.15% to 103.45% and the results have been found in good agreement with those results obtained by the reference methods.

scholarly journals Spectrophotometric Determination of Iron(II) and Cobalt(II) by Direct, Derivative, and Simultaneous Methods Using 2-Hydroxy-1-Naphthaldehyde-p-Hydroxybenzoichydrazone

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
V. S. Anusuya Devi ◽  
V. Krishna Reddy
Keyword(s):  
Detection Limit ◽  
Cobalt Content ◽  
Molar Absorptivity ◽  
Order Derivative ◽  
Spectrophotometric Methods ◽  
Biological Water ◽  
Highly Sensitive ◽  
Beer's Law ◽  
Beer’S Law

Optimized and validated spectrophotometric methods have been proposed for the determination of iron and cobalt individually and simultaneously. 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoichydrazone (HNAHBH) reacts with iron(II) and cobalt(II) to form reddish-brown and yellow-coloured [Fe(II)-HNAHBH] and [Co(II)-HNAHBH] complexes, respectively. The maximum absorbance of these complexes was found at 405 nm and 425 nm, respectively. For [Fe(II)-HNAHBH], Beer’s law is obeyed over the concentration range of 0.055–1.373 μg mL−1with a detection limit of 0.095 μg mL−1and molar absorptivityɛ, 5.6 × 104 L mol−1cm−1. [Co(II)-HNAHBH] complex obeys Beer’s law in 0.118–3.534 μg mL−1range with a detection limit of 0.04 μg mL−1and molar absorptivity,ɛof 2.3 × 104 L mol−1cm−1. Highly sensitive and selective first-, second- and third-order derivative methods are described for the determination of iron and cobalt. A simultaneous second-order derivative spectrophotometric method is proposed for the determination of these metals. All the proposed methods are successfully employed in the analysis of various biological, water, and alloy samples for the determination of iron and cobalt content.

scholarly journals Simple Spectrophotometric Method for Determination of Paroxetine in Tablets Using 1,2-Naphthoquinone-4-Sulphonate as a Chromogenic Reagent

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Ibrahim A. Darwish ◽  
Heba H. Abdine ◽  
Sawsan M. Amer ◽  
Lama I. Al-Rayes
Keyword(s):  
Spectrophotometric Method ◽  
Correlation Coefficients ◽  
Molar Absorptivity ◽  
Official Method ◽  
Calibration Data ◽  
Pharmaceutical Tablets ◽  
Relative Standard ◽  
Label Claim ◽  
Colored Product

Simple and rapid spectrophotometric method has been developed and validated for the determination of paroxetine (PRX) in tablets. The proposed method was based on nucleophilic substitution reaction of PRX with 1,2-naphthoquinone-4-sulphonate (NQS) in an alkaline medium to form an orange-colored product of maximum absorption peak () at 488 nm. The stoichiometry and kinetics of the reaction were studied, and the reaction mechanism was postulated. Under the optimized reaction conditions, Beer's law correlating the absorbance (A) with PRX concentration (C) was obeyed in the range of 1–8 g . The regression equation for the calibration data was: A = 0.0031 + 0.1609 C, with good correlation coefficients (0.9992). The molar absorptivity () was L  1 . The limits of detection and quantitation were 0.3 and 0.8 g , respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2%. The proposed method was successfully applied to the determination of PRX in its pharmaceutical tablets with good accuracy and precisions; the label claim percentage was %. The results obtained by the proposed method were comparable with those obtained by the official 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 Pyridoxine Hydrochlorine in Pharmaceutical Preparations and Foods

1997 ◽  
Vol 80 (6) ◽  
pp. 1368-1373 ◽  
Author(s):  
Kailasam Srtvidya ◽  
Natesan Balasubramanian
Keyword(s):  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Spectrophotometric Assay ◽  
Stable Complex ◽  
Pyridoxine Hydrochloride ◽  
Beer's Law ◽  
Rice Samples ◽  
Beer’S Law ◽  
Aqueous Volume

Abstract An easy and sensitive spectrophotometric assay of pyridoxine is described. The procedure is based on formation of an azo dye by the reaction of pyridoxine with diazotized 2,4-dinitroaniline followed by the reaction of the dye with Hg2+ ions to form a stable complex with maximum absorbance at 545 nm. The system obeys Beer’s law for 4–75 μg pyridoxine hydrochloride in an overall aqueous volume of 25 mL (correlation coefficient, 0.9998). On extraction into 5 mL butan-1-ol, the system obeys Beer’s law in the range 0.8–15 μg pyridoxine hydrochloride at 545 nm. The color is stable for 60 min in both aqueous and organic phases (molar absorptivity, 3.7 × 104 L/mol · cm; coefficient of variation, 3.1%, n = 10). The pyridoxine contents of pharmaceutical preparations, a processed foodstuff, and 2 rice samples were determined by using the proposed method. Assay reliability was established by recovery studies and parallel determination using a reported method.

scholarly journals Spectrophotometric Stability-Indicating Methods for the Determination of Leflunomide in the Presence of Its Degradates

2006 ◽  
Vol 89 (6) ◽  
pp. 1524-1531 ◽  
Author(s):  
Samah S Abbas ◽  
Lories I Bebawy ◽  
Laila A Fattah ◽  
Heba H Refaat
Keyword(s):  
Dosage Forms ◽  
Derivative Spectrophotometry ◽  
Reaction Conditions ◽  
Pharmaceutical Dosage Forms ◽  
First Derivative ◽  
Beer's Law ◽  
First Derivative Spectrophotometry ◽  
Colored Product ◽  
Beer’S Law

Abstract Five simple and sensitive methods were developed for the determination of leflunomide (I) in the presence of its degradates 4-trifluoromethyl aniline (II) and 3-methyl-4-carboxy isoxazole (III). Method A was based on differential derivative spectrophotometry by measuring the △1D value at 279.5 nm. Beer's law was obeyed in the concentration range of 2.0020.00 μg/mL with mean percentage accuracy of 100.07 1.32. Method B depended on first-derivative spectrophotometry and measuring the amplitude at 253.4 nm. Beer's law was obeyed in the concentration range of 2.0016.00 μg/mL with mean percentage accuracy of 98.42 1.61. Method C was based on the reaction of degradate (II) with 2,6-dichloroquinone-4-chloroimide (Gibbs reagent). The colored product was measured at 469 nm. Method D depended on the reaction of degradate (II) with para-dimethyl aminocinnamaldehyde (p-DAC). The absorbance of the colored product was measured at 533.4 nm. Method E utilized 3-methyl-2-benzothiazolinone hydrazone in the presence of cerric ammonium sulfate with degradate (II). The green colored product was measured at 605.5 nm. The linearity range was 40.00-280.00, 2.40-24.00, and 30-250 μg/mL with mean percentage accuracy of 100.75 1.21, 100.13 1.45, and 99.74 1.39 for Methods CE, respectively. All variables were studied to optimize the reaction conditions. The proposed methods have been successfully applied to the analysis of leflunomide in pharmaceutical dosage forms and the results were statistically compared with that previously reported.

scholarly journals Performance Characteristics of UV and Visible Spectrophotometry Methods for Quantitative Determination of Norfloxacin in Tablets

2014 ◽  
Vol 6 (3) ◽  
pp. 531-541 ◽  
Author(s):  
L. Chierentin ◽  
H. R. N. Salgado
Keyword(s):  
Absorption Maximum ◽  
Good Accuracy ◽  
Chloranilic Acid ◽  
Spectrophotometric Methods ◽  
Ich Guidelines ◽  
Label Claim ◽  
Acid Reagent ◽  
Development And Validation ◽  
Good Agreement

This work has proposed the development and validation of ultraviolet (UV) and visible (Vis) spectrophotometric methods for the determination of norfloxacin in the tablets. The proposed methods were applied to pharmaceutical formulation and percent amount of drug estimated (96.08% for UV method and 102.65% for Vis method) and was found in good agreement with the label claim. Using the UV method norfloxacin showed an absorption maximum at 277 nm, in 0.1 M hydrochloridric acid medium, whereas for the Vis spectrophotometric method it reacts with chloranilic acid reagent, forming a purple solution with an absorption maximum at 520 nm. The calibrations curves were linear over the working range of 2.0-7.0 ?g.mL-1 for the UV method and 90.0-120.0 ?g/mL for the Vis method. The linear regression equation for UV method was y = 0.1303x+0.0026 (r2=0.9999) and for Vis method y = 0.0037x-0.0069 (r2 = 0.9948), they proved to be linear. The methods were completely validated according to the International Conference Harmonization (ICH) guidelines, showing good accuracy, precision, selectivity, linearity and robustness. Therefore the both methods were found to be simple, rapid, sensitive, and easily contributing to the quality control of norfloxacin tablets while being interchangeable. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i3.18381 J. Sci. Res. 6 (3), 531-541 (2014)

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