scholarly journals Spectrophotometric methods for the determination of lisinopril in medicines

Pharmacia ◽  
2021 ◽  
Vol 68 (4) ◽  
pp. 811-818
Author(s):  
Nataliia Shulyak ◽  
Kateryna Budzivula ◽  
Tetyana Kucher ◽  
Liubomyr Kryskiw ◽  
Olha Poliak ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Amino Group ◽  
Carboxylic Group ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Beer's Law ◽  
Primary Amino ◽  
Beer’S Law ◽  
Medium Method

Two simple, rapid and green spectrophotometric methods are described for the determination of lisinopril medicines. The determination is based on the reaction of the primary amino group of the lisinopril with ninhydrin in aqueous medium (Method I) and reaction on the carboxylic group of the lisinopril with copper (II) sulfate (Method II). For both methods, optimal spectrophotometric conditions were established. The linear relationship was found between absorbance at λmax and concentration of drug in the range 40–60 µg/mL (Method I) and 0.592–2.072 mg/mL (Method II). Regression analysis of Beer’s law plot at 400 nm yielded the regression equation, y = 7.4929x – 0.0545 (Method I) and at 730 nm y = 0.0443x – 0.0832 (Method II). High values of correlations coefficient (R2 = 0.9917 (Method I) and R2 = 0.999 (Method II)) and small values of intercept validated the linearity of calibration curve and obedience to Beer’s law. The LOD and LOQ values were calculated to be 6.91 µg/mL and 23.01 µg/mL respectively (Method I) and 0.11 mg/mL and 0.36 mg/mL respectively (Method II). Intra-day and inter-day accuracy and precision were in acceptable limits. The proposed methods were applied for the quantification of lisinopril in tablets pertaining to three commercial formulations. Analytical eco-scale for greenness assessment of the proposed spectrophotometric methods showed that both methods correspond to excellent green analysis.

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 Spectrophotometric Determination of Paracetamol in bulk and Pharmaceutical Preparations

2015 ◽  
Vol 12 (2) ◽  
pp. 317-323
Author(s):  
Baghdad Science Journal
Keyword(s):  
Sodium Hydroxide ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Pharmaceutical Preparations ◽  
Coupling Reaction ◽  
Reaction Conditions ◽  
Accuracy And Precision ◽  
Beer's Law ◽  
Beer’S Law

A simple, and rapid spectrophotometric method for the estimation of paracetamol has been developed. The methods is based on diazotisation of 2,4-dichloroaniline followed by a coupling reaction with paracetamol in sodium hydroxide medium. All variables affecting the reaction conditions were carefully studied. Beer's law is obeyed in the concentration range of 4-350 ?gml?1 at 490 nm .The method is successfully employed for the determination of paracetamol in pharmaceutical preparations. No interferes observed in the proposed method. Analytical parameters such as accuracy and precision have been established for the method and evaluated statistically to assess the application of the method.

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 Sensitive and Rapid Spectrophotometric Methods for Determination of Anticancer Drugs

2002 ◽  
Vol 85 (5) ◽  
pp. 1021-1024 ◽  
Author(s):  
Padmarajaiah Nagaraja ◽  
Ramanathapura A Vasantha ◽  
Hemmige S Yathirajan
Keyword(s):  
Anticancer Drugs ◽  
Pharmaceutical Formulations ◽  
Subsequent Reaction ◽  
Vincristine Sulfate ◽  
Spectrophotometric Methods ◽  
Hydrochloric Acid Medium ◽  
Beer's Law ◽  
Beer’S Law ◽  
Vinblastine Sulfate

Abstract Sensitive, rapid, and simple spectrophotometric methods were developed for determination of the anticancer drugs vinblastine sulfate (VBS) and vincristine sulfate (VCS), which belong to the class of vinca alkaloids. The first method is based on the reaction of VBS and VCS with diazotized dapsone, forming yellow azo products with absorption maxima at 430 nm. The colored species obey Beer's law in the concentration range of 0.5–24 μg/mL for VBS and 0.5–12 μg/mL for VCS. The second method describes the reaction of VBS and VCS with iron(III) and subsequent reaction with ferricyanide in hydrochloric acid medium to yield blue products with absorption maxima at 750 nm. The Beer's law range for this method is 0.1–4 μg/mL for VBS and 0.5–10 μg/mL for VCS. With both methods, colored species were stable for 1 h. The methods are simple and reproducible and are applied for determination of VBS and VCS in pharmaceutical formulations. Commonly encountered pharmaceuticals added as excipients do not interfere in the analysis and the results obtained in the analysis of dosage forms agree well with the labeled contents.

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 Non-extractive spectrophotometric determination of valsartan in pure form and in pharmaceutical products by ion-pair complex formation with bromophenol blue and methyl red

Pharmacia ◽  
2021 ◽  
Vol 68 (4) ◽  
pp. 851-858
Author(s):  
Kateryna Peleshok ◽  
Bohdana Bondar ◽  
Liubomyr Kryskiw ◽  
Tetyana Kucher ◽  
Olha Poliak ◽  
...  
Keyword(s):  
Pharmaceutical Products ◽  
Ion Pair ◽  
Bromophenol Blue ◽  
Methyl Red ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Beer's Law ◽  
Beer’S Law ◽  
Coloured Complex ◽  
Tablet Dosage

Two simple, rapid, green non extractive spectrophotometric methods are described for the estimation of valsartan in tablet dosage form. The determination is based on the ion-pair formation using the dyes, bromophenol blue (BPB) and methyl red (MR). Valsartan forms ion-pair complex selectively with the dyes, as indicated by the formation of a coloured complex with BPB at pH 5.5 with λmax at 424 nm and MR at pH 4.3 with λmax at 494 nm. For both methods, optimal spectrophotometric conditions were established. The linear relationship was found between absorbance at λmax and concentration of drug in the range 8–24 µg/mL for BPB and 4–20 µg/mL for MR. Regression analysis of Beer’s law plot at 424 nm yielded the regression equation, y = 0.0102x + 01636 (BPB) and at 494 nm y = 0.0222x – 0.0063 (MR). High values of correlations coefficient (R2 = 0.9988 (BPB) and R2 = 0.9991 (MR)) and small values of intercept validated the linearity of calibration curve and obedience to Beer’s law. The LOD and LOQ values were calculated to be 1.03 µg/mL and 3.43 µg/mL respectively (BPB) and 0.68 µg/mL and 2.26 µg/mL respectively (MR). Intra-day and inter-day accuracy and precision, robustness were in acceptable limits. The proposed methods were applied for the quantification of valsartan in tablets pertaining to three commercial formulations. Analytical eco-scale for greenness assessment of the proposed spectrophotometric methods showed that both methods corresponds to excellent green analysis with a score of 89.

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 A spectrophotometric method for determination of fluorophore-to-protein ratios in conjugates of the blue fluorophore 7-amino-4-methylcoumarin-3-acetic acid (AMCA)

1990 ◽  
Vol 38 (1) ◽  
pp. 87-94 ◽  
Author(s):  
M W Wessendorf ◽  
S J Tallaksen-Greene ◽  
R M Wohlhueter
Keyword(s):  
Acetic Acid ◽  
Optical Density ◽  
Extinction Coefficient ◽  
Spectrophotometric Method ◽  
Extinction Coefficients ◽  
Beer's Law ◽  
Beer’S Law ◽  
The Given

7-Amino-4-methylcoumarin-3-acetic acid (AMCA) has been found to be a useful fluorophore for immunofluorescence. The present study describes a spectrophotometric method for determining the ratio of moles AMCA to moles protein (or the f/p ratio) in an AMCA-conjugated IgG. The concentration of a substance absorbing light can be determined spectrophotometrically using Beer's Law: Absorbance = Concentration x Extinction coefficient. From Beer's law, one can derive the following formula for determining the f/p ratio of AMCA-IgG conjugates: f/p = (epsilon 280IgG).A350 - (epsilon 350IgG).A280/(epsilon 350AMCA).A280 - (epsilon 280AMCA).A350 where A is the optical density of the conjugate at the given wavelength and epsilon is the extinction coefficient of a substance at the wavelength specified. Using conjugates of model proteins, it was found that the extinction coefficients of the AMCA moiety of AMCA-conjugated protein were 1.90 x 10(4) at 350 nm and 8.29 x 10(3) at 280 nm. Similarly, it was found that the extinction coefficients of swine IgG were 1.56 x 10(3) at 350 nm and 1.26 x 10(5) at 280 nm. Thus, for AMCA-conjugated swine IgG: f/p = (1.26 x 10(5)).A350 - (1.56 x 10(3)).A280/(1.47 x 10(4)).A280 - (6.42 x 10(3)).A350 [corrected]. Based on this formula, the f/p ratios of some AMCA-IgG conjugates useful for immunohistochemistry have been found to range between 6 and 24.

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