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.

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.

New, simple and validated UV-spectrophotometric methods for the estimation of sodium usnate in preparations

2010 ◽  
Vol 29 (2) ◽  
pp. 157 ◽  
Author(s):  
Ivana Savić ◽  
Goran Nikolić ◽  
Ivan Savić ◽  
Saša Zlatković ◽  
Dragiša Djokić
Keyword(s):  
Phosphate Buffer ◽  
Pharmaceutical Preparations ◽  
High Sensitivity ◽  
Cost Effective ◽  
Sensitivity Coefficient ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Ich Guidelines ◽  
Beer’S Law

New, simple, cost effective, accurate and reproducible UV-spectrophotometric methods were developed and validated for the estimation of sodium usnate in pharmaceutical preparations. Sodium usnate was estimated at 290 nm in water and phosphate buffer (pH 3):methanol (11:20 V/V). Beer’s law was obeyed in the concentration range of 0.1–5 μg·cm−3 (r = 0.997) in water and 1–12 μg·cm−3 (r = 0.999) in the phosphate buffer:methanol. The apparent molar absorptivity and Sandell’s sensitivity coefficient were found to be 3.16×104 dm3·mol−1·cm−1 and 11.58 ng·cm–2/0.001 A in water and 3.72×104 dm3·mol−1·cm−1 and 9.83 ng·cm–2/0.001 A in phosphate buffer:methanol, respectively, indicating the high sensitivity of the proposed methods. These methods were tested and validated for various parameters according to ICH guidelines. The detection and quantitation limits were found to be 0.0721 and 0.2163 μg·cm–3 in water and 0.163, 0.489 μg·cm−3 in phosphate buffer:methanol, respectively. The proposed methods were successfully applied for the determination of sodium usnate in pharmaceutical preparations. The results demonstrated that the procedure is accurate, precise and reproducible (R.S.D. < 2 %).

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 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 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 Application of Cerium (IV) as an Oxidimetric Agent for the Determination of Ethionamide in Pharmaceutical Formulations

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Kanakapura Basavaiah ◽  
Nagib A. S. Qarah ◽  
Sameer A. M. Abdulrahman
Keyword(s):  
Quality Control ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Sample Solution ◽  
Standing Time ◽  
Spectrophotometric Methods ◽  
Ich Guidelines ◽  
Back Titration ◽  
Bulk Drug

Two simple methods are described for the determination of ethionamide (ETM) in bulk drug and tablets using cerium (IV) sulphate as the oxidimetric agent. In both methods, the sample solution is treated with a measured excess of cerium (IV) solution in H2SO4 medium, and after a fixed standing time, the residual oxidant is determined either by back titration with standard iron (II) solution to a ferroin end point in titrimetry or by reacting with o-dianisidine followed by measurement of the absorbance of the orange-red coloured product at 470 nm in spectrophotometry. In titrimetry, the reaction proceeded with a stoichiometry of 1 : 2 (ETM : Ce (IV)) and the amount of cerium (IV) consumed by ETM was related to the latter’s amount, and the method was applicable over 1.0–8.0 mg of drug. In spectrophotometry, Beer’s law was obeyed over the concentration range of 0.5–5.0 μg/mL ETM with a molar absorptivity value of 2.66 × 104 L/(mol·cm). The limits of detection (LOD) and quantification (LOQ) calculated according to ICH guidelines were 0.013 and 0.043 μg/mL, respectively. The proposed titrimetric and spectrophotometric methods were found to yield reliable results when applied to bulk drug and tablets analysis, and hence they can be applied in quality control laboratories.

scholarly journals Spectrophotometric assay of Nicotinamide in Pharmaceutical Dosages

2021 ◽  
Vol 2063 (1) ◽  
pp. 012017
Author(s):  
Basima A A Saleem ◽  
Raghad A M Hamoo ◽  
Ghassan Q Ismail
Keyword(s):  
Charge Transfer ◽  
Reduction Reaction ◽  
Molar Absorptivity ◽  
Charge Transfer Reaction ◽  
Colored Complex ◽  
Spectrophotometric Methods ◽  
Oxidation Reduction ◽  
Beer's Law ◽  
Beer’S Law ◽  
Transfer Method

Abstract The reaction of nicotinamide and alizarin reagent using charge transfer reaction at a pH of 5.54 lead to produce a red colored compound measured at 527 nm., while the blue colored complex was formed using the oxidation reduction reaction between nicotinamide and chromate at pH 3.49 in the presence of an indigo cochineal dye. Theses tow colored products were measured at 527 and 610 nm respectively using two simple, fast and an accurate spectrophotometric methods. The linearity of the charge transfer method was followed Beer’s law 0.4 - 32 μg while the oxidation reduction method was obeyed Beer’s law from 1.6 - 40 μg in depending on the concentration range. Molar absorptivity was 1.95×104 and 2.16×104 mol−1 cm−1 for the red and blue colored complex respectively. Finally, the values of Sandal’s sensitivity were 0.00626 and 0.00565 μg−2 cm−1 for the first and second methods respectively. These two methods have been applied to quantify the amount of nicotinamide in pharmaceuticals with good recovery.

scholarly journals Spectrophotometric Methods for the Determination of the Antidepressant Drug Paroxetine Hydrochloride in Tablets

2005 ◽  
Vol 88 (2) ◽  
pp. 490-495 ◽  
Author(s):  
Armağan Önal ◽  
Evrim.Ş Kepekçi ◽  
Aysel Öztunç
Keyword(s):  
Antidepressant Drug ◽  
Coupling Reaction ◽  
Bromocresol Green ◽  
Bromophenol Blue ◽  
Complex Species ◽  
Spectrophotometric Methods ◽  
Beer's Law ◽  
Beer’S Law ◽  
Paroxetine Hydrochloride

Abstract Simple, sensitive, and accurate visible spectrophotometric methods are described for the determination of paroxetine hydrochloride (PA) in tablets. Among them, the first 3 methods are based on the ion-pair complexes of PA formed with bromothymol blue (BTB), bromophenol blue (BPB), and bromocresol green (BCG) in aqueous acidic buffers. The complex species extracted into chloroform were quantitatively measured at 414 nm with BTB and BCG and at 412 nm with BPB. Beer's law was obeyed over the concentration ranges of 2–20, 2–16, and 2–16 μg/mL, respectively. The fourth method described is based on a coupling reaction between PA and 7-chloro-4-nitrobenzofurazon (NBD-Cl) in borate buffer, pH 8.5, in which a yellow reaction product that was measured at 478 nm was formed. The Beer's law range for this method was 2–10 μg/mL. The last method developed describes the interaction of PA base, as an n-electron donor, with 7,7,8,8-tetracyanoquinodimethane (TCNQ), as a π-acceptor, in acetonitrile to give blue-colored TCNQ− radical anion with absorption maxima at 750 and 845 nm. Measured at 845 nm, the absorbance–concentration plot was rectilinear over the range of 1.5–15 μg/mL. The new methods developed were successfully applied to the determination of PA in tablets without any interference from common tablet excipients. The results of the methods were in good agreement with those obtained with an official liquid chromatographic method. This report describes first colorimetric methods for the determination of PA.

scholarly journals Determination of Cefixime Using Batch, Cloud Point Extraction and Flow Injection as New Spectrophotometric Methods

2019 ◽  
Vol 30 (3) ◽  
pp. 28
Author(s):  
Nisreen Kais Abood ◽  
Mohammed Jasim M. Hassan ◽  
Muneer A. AL-Da'amy
Keyword(s):  
Bisphenol A ◽  
Cloud Point ◽  
Flow Injection ◽  
Cloud Point Extraction ◽  
Pharmaceutical Formulations ◽  
Sample Volume ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Beer's Law ◽  
Beer’S Law

Three simple, sensitive, selective, accurate and efficient spectrophotometric methodsfor determining cefixime in bulk drug and pharmaceutical formulations havedescribed. The first method involved conversion of NH 2 in cefixime to diazoniumsalt, which has coupled with Bisphenol A in an alkaline medium. The orange coloredproduct showed λ max at 490 nm and followed Beer's law over a concentration range of1-50 μg mL -1 , with molar absorptivity of 0.866×10 4 L.mol -1 .cm -1 and the detectionlimit was 0.157 μg.mL -1 . The second method involved pre-concentration of a traceamount of cefixime-azo dyes using cloud point extraction (CPE). The extracted drug-dye was spectrophotometrically measured at λ max 500. The constructed calibrationcurve to determine cefixime followed Beer’s law in a range of 0.25-6 μg.mL -1 , with acorrelation coefficient of 0.9998, molar absorptivity of 0.961×10 5 L.mol -1 .cm -1 andthe detection limit was equal to 0.031 μg.mL -1 . The pre-concentration factor was 25and distribution coefficient (D) was 314.03.A diazotization of the studied drug (cefixime) and its coupling with Bisphenol A wasstudied using a developed flow injection analysis method, based on the detection ofthe absorption of the diazotization product. Chemical and physical properties [ofwhat??] were studied to develop the suggested method and to determine the stabilityof the colored of product. A flow rate of 2.5 mL.min -1 , 50 cm reaction coil and 100μL sample volume were used to operate the system and the orange colored productwas detected at 490 nm. The proposed three methods were successfully applied todetermine cefixime in pharmaceutical formulation, where results were satisfactory

scholarly journals Development of Method for Extractive Spectrophotometric Determination of Fe(III) with 2-Hydroxy-1-Naphthalene Carboxaldehyde Phenyl Hydrazone as an Analytical Reagent

2013 ◽  
Vol 14 ◽  
pp. 7-12
Author(s):  
Ratnamala P. Sonawane ◽  
R.S. Lokhande ◽  
Utkarsha M. Chavan
Keyword(s):  
Ethyl Acetate ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Beer's Law ◽  
Beer’S Law ◽  
Coloured Complex ◽  
Analytical Reagent

A spectrophotometric method has been developed for the determination of Fe(III) using 2-Hydroxy-1-Naphthalene carboxaldehyde phenyl hydrazone as an extractive reagent. The reagent forms a coloured complex, which has been quantitatively extracted into ethyl acetate at pH 6. The method obeys Beer’s law over arrange from 1 to 7 ppm. The Molar absorptivity and Sandell’s sensitivity were 0.31 × 104 L mol-1cm-1 and 0.13 μg cm-2 respectively. The proposed method is very sensitive and selective. The method has been successfully applied to synthetic and commercial samples.

Sign in / Sign up

Export Citation Format

Share Document