scholarly journals New Diazo Coupling Reactions for Visible Spectrophotometric Determination of Alfuzosin in Pharmaceutical Preparations

2007 ◽  
Vol 4 (4) ◽  
pp. 496-501 ◽  
Author(s):  
M. Vamsi Krishna ◽  
D. Gowri Sankar

Simple, rapid and sensitive spectrophotometric procedures were developed for the analysis of Alfuzosin hydrochloride (AFZ) in pure form as well as in pharmaceutical formulations. The methods are based on the reaction of AFZ with nitrite in acid medium to form diazonium ion, which is coupled with ethoxyethylenemaleic ester (Method A) or ethylcyanoacetate (Method B) or acetyl acetone (method C) in basic medium to form azo dyes, showing absorption maxima at 440, 465 and 490 nm respectively. Beer’s law is obeyed in the concentration of 4-20 μg/mL of AFZ for methods A, B and 3-15 μg/mL of AFZ for method C. The molar absorptivity and sandell’s sensitivity of AFZ- ethoxyethylenemaleic ester, AFZ- ethylcyanoacetate and AFZ-acetyl acetone are1.90 × 104, 0.022; 1.93 × 104, 0.021 and 2.67 × 104L mole-1cm-1, 0.015 μg cm-2respectively. The optimum reaction conditions and other analytical parameters were evaluated. The methods were successfully applied to the determination of AFZ in pharmaceutical formulations.


2011 ◽  
Vol 8 (1) ◽  
pp. 281-287 ◽  
Author(s):  
K. Srikanth ◽  
K. A. Emmanuel

In the present study, two simple, sensitive and reproducible visible spectrophotometric methods were developed for the determination of reboxetine in pure form and in pharmaceutical formulations. The methods involve acid hydrolysis of reboxetine methane sulphonate (Reboxetine as methane sulphonate) and the product obtained was used for the estimation. Out of the two methods developed in the laboratory, the first method involves the condensation reaction of hydrolysed reboxetine methane sulphonate with ethyl acetoacetate in sulphuric acid medium and the second method involves the diazocoupling reaction of hydrolysed reboxetine methane sulphonate with diazotizedp-sulphanilic acid in alkaline medium. They have absorption maxima at 400 nm and 430 nm respectively and obey Beer’s law in the concentration ranges of 0.5 - 0.3 μgmL-1and 1.0 - 7.5 μgmL-1respectively. Results of analysis were validated statistically and by recovery studies. The apparent molar absorptivity values (∈max) obtained are 7.549 x 104L mol-1cm-11 and 2.656x104Lmol-1cm-1respectively. Both these have correlation coefficient value of 0.9999. The proposed methods have good precision and accuracy.



2019 ◽  
Vol 16 (4(Suppl.)) ◽  
pp. 1010
Author(s):  
Aziz Et al.

     Tow simple, rapid and sensitive spectrophotometric methods for the determination of mesalazine in pharmaceutical preparations have been carried out. The proposed methods depend on oxidative coupling reaction of mesalazine with m-aminophenol in the existence of N-bromosuccinamide in alkaline medium (method A) and 2,6-dihydroxybenzoic acid in the existence of sodium metaperiodate in basic medium (method B) to produce colored products , show highest absorptions at 640 (nm) and 515 (nm), alternately. Beer’s law was consistent in concentrations extent of 1.25-30 and 0.5-12.5 (µg.mL-1) with molar absorptivity of 0.36×104 and 0.77×104 L.mol-1.cm-1, alternately. The limits of detection (LOD) were 0.0144 and 0.0829   µg.mL-1, while limits of quantitation (LOQ) were 0.0483 and 0.2766 (µg.mL-1), alternately. The suggested methods have been applied successfully to the determination of mesalazine in its pharmaceutical preparations as tablets and suppositories.



Author(s):  
Abbas Shebeeb Al-kadumi ◽  
Sahar Rihan Fadhel ◽  
Mohammed Abdullah Ahmed ◽  
Luma Amer Musa

We proposed two simple, rapid, and convenient spectrophotometric methods are described for the determination of Amoxicillin in bulk and its pharmaceutical preparations. They are based on the measurement of the flame atomic emission of potassium ion (in first method) and colorimetric determination of the green colored solution for manganite ion at 610 nm formed after reaction of Amoxicillin with potassium permanganate as oxidant agent (in the second method) in basic medium. The working conditions of the methods were investigated and optimized. Beer's law plot showed a good correlation in the concentration range of 5-45 μg/ml. The detection limits and relative standared deviations were (2.573, 2.814 μg/ml) (2.137, 2.498) for the flame emission photometric method and (1.844, 2.016 μg/ml) (1.645,1.932) for colorimetric methods for capsules and suspensions respectively. The methods were successfully applied to the determination of Amoxicillin in capsules and suspensions, and the obtained results were in good agreement with the label claim. No interference was observed from the commonly encountered additives and expectancies.



2006 ◽  
Vol 4 (4) ◽  
pp. 708-722 ◽  
Author(s):  
Akram El-Didamony ◽  
Alaa Amin ◽  
Ahmed Ghoneim ◽  
Ayman Telebany

AbstractFour simple, accurate, sensitive and economical procedures (A–D) for the estimation of gentamicin sulphate and vancomycin hydrochloride, both in pure form and in pharmaceutical formulations have been developed. The methods are based on the oxidation of the studied drugs by a known excess of potassium permanganate in sulphuric acid medium and subsequent determination of unreacted oxidant by reacting it with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. The reacted oxidant corresponds to the drug content. Regression analysis of Beer-Lambert plots showed good correlations in the concentration ranges 4–8, 3–8, 4–9 and 5–9 µg ml−1 with gentamicin and 4–8, 1.5–4, 1.5–4 and 3.5–5.5 µg ml−1 with vancomycin for methods A, B, C, and D, respectively. The molar absorptivity, sandell sensitivity, detection and quantification limits were calculated. The stoichiometric ratios for the cited drugs were studied. The optimum reaction conditions and other analytical parameters were evaluated. The influence of the substance commonly employed as excipients with these drugs were studied. The proposed methods were applied to the determination of these drugs in pharmaceutical formulations. The results have demonstrated that the methods are equally accurate and reproducible as the official methods.



2009 ◽  
Vol 15 (2) ◽  
pp. 69-76 ◽  
Author(s):  
S.M. Al-Ghannam ◽  
A.M. Al-Olyan

A sensitive spectrophotometric method was developed for the determination of some 1,4-dihydropyridine compounds namely, nicardipine and isradipine either in pure form or in pharmaceutical preparations. The method is based on the reduction of nicardipine and isradipine with zinc powder and calcium chloride followed by further reduction with sodium pentacyanoaminoferrate (II) to give violet and red products having the absorbance maximum at 546 and 539 nm with nicardipine and isradipine, respectively. Beer's law was obeyed over the concentration range 8.0-180 ?g/ml with the detection limit of 1.67 ?g/ml for nicardipine and 8.0-110 ?g/ml with the detection limit of 1.748 ?g/ml for isradipine. The analytical parameters and their effects on the reported methods were investigated. The molar absorptivity, quantization limit, standard deviation of intercept (Sa), standard deviation of slope (Sb) and standard deviation of the residuals (Sy/x) were calculated. The composition of the result compounds were found 1:1 for nicardipine and 1:2 for isradipine by Job's method and the conditional stability constant (Kf) and the free energy changes (?G) were calculated for compounds formed. The proposed method was applied successfully for the determination of nicardipine and isradipine in their dosage forms. The results obtained were in good agreement with those obtained using the reference or official methods. A proposal of the reaction pathway was presented.



2013 ◽  
Vol 10 (3) ◽  
pp. 1005-1013 ◽  
Author(s):  
Baghdad Science Journal

A simple, accurate, precise, rapid, economical and a high sensitive spectrophotometric method has been developed for the determination of tadalafil in pharmaceutical preparations and industrial wastewater samples, which shows a maximum absorbance at 204 nm in 1:1 ethanol-water. Beer's law was obeyed in the range of 1-7?g/ mL ,with molar absorptivity and Sandell ? s sensitivity of 0.783x105l/mol.cm and 4.97 ng/cm2respectively, relative standard deviation of the method was less than 1.7%, and accuracy (average recovery %) was 100 ± 0. 13. The limits of detection and quantitation are 0.18 and 0.54 µg .ml-1, respectively. The method was successfully applied to the determination of tadalafil in some pharmaceutical formulations (tablets) and industrial wastewater samples. The proposed method was validated by sensitivity and precision which proves suitability for the routine analysis of tadalafil in true samples.



2002 ◽  
Vol 70 (1) ◽  
pp. 49-55
Author(s):  
Abou-Attia Fekria M. ◽  
Issa Y.M. ◽  
El Reis M.A. ◽  
Aly F.A. ◽  
Abd El- MoetY M.

The formation of the azo-dye using chromotropic acid as a coupling agent was applied to the determination of five sulphonamides. The spectrophotometric studies as well as microanalysis of the studied sulphonamides- chromotropic acid azo dyes revealed the existence of the 1:1 coupling product. The absorbance of the formed azo dye is measured at 510 nrn, and has a large molar absorptivity (ε = 2.87 - 3.29 × 104 1 mol−1cm−1). Beer's law was obeyed over the concentration range 0.5-9.0 µg ml−1. The assay results of pharmaceutical formulations showed good accuracy and precision over the concentration range used. The proposed method avoids time-consumption, extraction process and temperature control.



Author(s):  
Hawraa Ali ◽  
Sumayha Muhammed

     Simple and rapid spectrophotometric determination of furosemide (FUR) has been investigated .The method is based on acid hydrolysis of FUR to free primary aromatic amine and diazotization followed by coupling with 3, 5 di methyl phenol (3, 5-DMPH) at basic medium. The absorbance was measured at 434 nm, the method was optimized for best condition, and beers’ law is obeyed over the range of 0.4-50 µg.mL-1 with molar absorptivity and sandal’s sensitivity 1.3899 x104 L moL-1 .cm-1 and 0.0238x104 µg.cm-2 respectively. Analysis of solution containing nineteen different concentrations of FUR gave a correlation coefficient of (0.9999) and limit of detection, limit of quantitation were 0.127, 0.464µg.mL-1 respectively. The reaction stoichiometry was evaluated by Job’s and mole ratio method was found to be 1:1(diazotized FUR: 3, 5-DMPH) .The method was applied in synthetic urine and pharmaceutical formulation. The recovery of FUR in spiked urine was satisfactory resulting in the values of (99±3.32) %, the results of the suggested method was compared with available official literature method.



2021 ◽  
Vol 2 (3) ◽  
pp. 49-61
Author(s):  
Basima Ahmed Abed Al-Hadi Saleem

A new spectrophotometric method is used for estimating Thiamine hydrochloride in its pure form and pharmaceutical formulations, the present method depends on the reaction between Thiamine hydrochloride and chrome azurol S to form a red complex which exhibit maximum absorption at 510 nm, the addition of Sulphite to the resulted red complex is bleaching it and this step was used for the determination of Sulphite which is considered an attacker of Thiamine hydrochloride, therefore, this method was developed for determination of Thiamine hydrochloride in presence of Sulphite. The linearity of the proposed method was obeyed Beer’s law from 2 to 48 and 0.04 to 2.4 ppm for Thiamine hydrochloride and Sulphite respectively. Also, the method sensitivity was measured by molar absorptivity values 5.9×104 l.mol-1.cm-1 and 1.68×104 l.mol-1.cm-1 for Thiamine hydrochloride and Sulphite respectively. The present method accuracy (average recovery) 100.06% and 100.04% the precision (RSD) of the method is ±0.98 - ±1.27% and ±0.76 - ±1.47 of Thiamine hydrochloride and Sulphite respectively. This method was applied for the estimation of B1 and SO32- in pharmaceutical preparations and various water samples respectively.



2007 ◽  
Vol 4 (4) ◽  
pp. 480-486 ◽  
Author(s):  
B. Krishna Priya ◽  
P. Subrahmanyam ◽  
K. Dakshayani ◽  
P. Chiranjeevi

Novel spectrophotometric methods were developed for the determination of fenpropathrin in insecticidal formulations and water samples. The methods were based on the hydrolysis of fenpropathrin with ethanolic KOH to form 3-phenoxy benzaldehyde. The resultant aldehyde group was condensed with anthranilic acid in presence of basic medium to form yellowish red color product having λmaxof 485 nm or condensed with 2-chloro phenyl hydrazine to form pink color product having λmaxof 557 nm. The color derivatives were correspondingly stable for 5 and 8 days. The Beer's law was obeyed over the range from 0.03-10.0 µg mL-1and molar absorptivity 2.586×104L mol-1cm-1for anthranilic acid and from 0.02-8.0 µg mL-1and molar absorptivity 3.924×104L mol-1cm-1for 2-chloro phenyl hydrazine were observed. The optimum reaction conditions and other analytical parameters were established. The proposed methods have been applied for the analysis of water samples.



Sign in / Sign up

Export Citation Format

Share Document