scholarly journals Spectrophotometric Determination of Antidepressant Drug Duloxetine in Pharmaceutical Preparations using π-Acceptors

2012 ◽  
Vol 9 (1) ◽  
pp. 323-329 ◽  
Author(s):  
Sidika Ertürk Toker ◽  
Armagan Önal

In this study, two simple and accurate spectrophotometric methods were presented for the determination of duloxetine hydrochloride (DLX) in pharmaceutical preparations. The methods were based on the reaction of DLX asn-electron donor with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π-acceptors to give highly colored complex species. The colored products were quantitated spectro-photometrically at 477 and 841 for DDQ, TCNQ, respectively. All variables were studied in order to optimize the reaction conditions. Beer's law was obeyed in the concentration ranges 10.0-50.0 and 15-60 μg mL−1for DDQ and TCNQ method, respectively. The proposed methods have been successfully applied to the pharmaceutical analysis without any interference from excipients. The suggested procedures could be used for the determination of DLX in pharmaceutical preparations being sensitive, simple and selective.

2013 ◽  
Vol 10 (3) ◽  
pp. 971-976
Author(s):  
Baghdad Science Journal

Simple, sensitive and economical spectrophotometric methods have been developed for the determination of cefixime in pure form. This method is based on the reaction of cefixime as n-electron donor with chloranil to give highly colored complex in ethanol which is absorb maximally at 550 nm. Beer's law is obeyed in the concentration ranges 5-250 µg ml-1 with high apparent molar absorptivities of 1.52×103 L.mole-1. cm-1.


2003 ◽  
Vol 86 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Lories I Bebawy ◽  
Yosry M Issa ◽  
Kamal M Abdel Moneim

Abstract Simple, rapid, accurate, and sensitive spectrophotometric methods are described for the determination of dicyclomine hydrochloride. The methods are based on the reaction of this drug as an n-electron donor with 2,3-dichloro-5,6-dicyano-p-benzoqunione (DDQ), p-chloranilic acid (p-CA), and chloranil (CL) as Π-acceptors to give highly colored complex species. The colored products are measured spectrophotometrically at 456, 530, and 650 nm for DDQ, p-CA, and CL, respectively. Optimization of the different experimental conditions were studied. Beer's law was obeyed in concentration ranges of 20–100, 50–250, and 80–600 μg/mL for DDQ, p-CA, and CL, respectively. Colored complexes are produced in organic solvents and are stable for at least 1 h. The methods were applied to Spasmorest™ antispasmotic tablets and ampoules with good accuracy and precision.


1980 ◽  
Vol 63 (5) ◽  
pp. 992-995
Author(s):  
Laila Elsayed ◽  
Sayed M Hassan ◽  
Khadiga M Kelani ◽  
Hamed M El-Fatatry

Abstract Two spectrophotometric methods have been developed for the simultaneous determination of nifuroxime and furazolidone in their pharmaceutical preparations. No preliminary separation step is required in either method. The first, a modified Vierordt method, gives accurate and reproducible results for both drugs. Mean percent recoveries for nifuroxime and furazolidone were 99.50 ±1.59 and 100.20 ±1.16 (P = 0.05), respectively. This method also gives accurate and reproducible results for the determination of nifuroxime and furazolidone in their pharmaceutical preparations: Tricofuran vaginal suppositories and powder. The second method, which involves the use of the first-derivative curves, gives unreliable results; the reasons for these are discussed.


2015 ◽  
Vol 1 (2) ◽  
pp. 11 ◽  
Author(s):  
Safwan Mohammad Fraihat

Two spectrophotometric methods were developed for the determination Tadalafil in pharmaceutical preparations. The methods are based on the oxidation reaction with known excess amount of Ce(IV) and estimation of the unreacted amount using Indigo carmine dye (Method A) and in Methylene blue dye  (Method B). the factors affecting the reaction conditions were studied and the absorbance of absorbance of the oxidation reaction products were monitored at 610 and 600 nm for methods A and B respectively. Beer's law is obeyed in the concentration ranges 11 to 50 and 10 to 55 ppm, the limits of detection and quantification are reported. The proposed method was applied to the determination of the drug in pharmaceutical formulations and the results demonstrated that the method is equally accurate, precise and reproducible as the official methods. The validity of method was established by recovery studies with satisfactory results.


2005 ◽  
Vol 88 (2) ◽  
pp. 490-495 ◽  
Author(s):  
Armağan Önal ◽  
Evrim.Ş Kepekçi ◽  
Aysel Öztunç

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.


2011 ◽  
Vol 25 (6) ◽  
pp. 303-315 ◽  
Author(s):  
Akram M. El-Didamony ◽  
Eman A. H. Erfan

Three visible spectrophotometric methods (A–C) were developed for the analysis of someβ-blocker drugs, namely atenolol (ATE) and timolol (TIM) based on their reactivity with bromine, generated in situ by the action of hydrochloric acid on bromate–bromide mixture. The determination of residual bromine is based on its ability to bleach the indigo carmine dye and measuring the absorbance at 610 nm (method A). Methods B and C involve treating the unreacted bromine with a measured excess of iron (II), the remaining iron (II) is complexed with 1,10-phenanthroline (method B) or with 2,2'-bipyridyl (method C) and measuring the increase in absorbance at 510 and 522 nm, respectively. In all the methods, the amount of bromine reacted corresponding to the drug content. Regression analysis of Beer's plot showed good correlation in the concentration ranges of 0.4–16.4, 0.8–10.4 and 0.4–12.8 µg/ml using methods A–C, respectively, for ATE and 14–38, 12–32 and 14–38 µg/ml using methods A–C, respectively, for TIM. The optimum reaction conditions and other analytical parameters are evaluated. No interference was observed from the additives and the applicability of the methods was tested by analyzing the pharmaceutical preparations containing the investigated drugs. Statistical comparison of the results with those of official methods shows excellent agreement and indicates no significant difference in precision.


2009 ◽  
Vol 6 (2) ◽  
pp. 537-540 ◽  
Author(s):  
Manish Majumder ◽  
B. Gopinath ◽  
Girish Koni ◽  
Sanjeev Kumar Singh

Two new, selective and sensitive visible spectrophotometric methods (method A and B) have been developed for the estimation of tinofovir in bulk and in pharmaceutical preparations. Tinofovir was subjected to acid hydrolysis and this acid hydrolyzed drug was used for the estimation. Method A is based on the reaction with 3-methyl-2-benzothiazolinone hydrazone in the presence of ferric chloride, to form a colored species with a λmaxat 628.5 nm. Method B is based on the reaction with Folin-ciocalteu phenol’s reagent under alkaline condition with a λmaxat 768 nm. Beer’s law is obeyed in the concentration range of 5-40 µg/mL for method A and 2-30 µg/mL for method B, respectively. The methods were extended to pharmaceutical formulations and there was no interference from any common pharmaceutical excepients and diluents. The result of analysis has been validated statistically and by recovery studies.


2015 ◽  
Vol 12 (2) ◽  
pp. 317-323
Author(s):  
Baghdad Science Journal

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.


Author(s):  
P. V. Lakshmana Rao ◽  
C. Rambabu

Objective: The authors report two simple, accurate and economic spectrophotometric methods A and B for the determination of Itopride hydrochloride in bulk and dosage forms.Methods: The proposed methods are based on the formation of chloroform soluble ion-associates in the presence of acidic dyes namely BPB (Method A) and BCP (Method B) exhibiting lmax at 418 and 418 nm respectively.Results: Beer’s law is found to be obeyed in the concentration range of 2.0-10.0 µg/ml and 2.0-10.0 µg/ml. The molar absorptivities are found to be 1.42x104 and 9.61x103L/mol. cm for methods A and B. These methods are successfully applied for the assay of Itopride hydrochloride in pharmaceutical formulations.


2008 ◽  
Vol 5 (4) ◽  
pp. 713-717 ◽  
Author(s):  
Zaheer Ahmed ◽  
Y. N. Manohara ◽  
K. P. Channabasawaraj ◽  
Manish Majumdar

Two selective and sensitive spectrophotometric methods have been developed for the estimation of adefovir dipivoxil in bulk and pharmaceutical preparations. Adefovir dipivoxil was subjected to acid hydrolysis and the hydrolysed product used for the estimation. The methods are based on the reaction with 3-methyl-2-benzothiazolinone hydrazone in the presence of ferric chloride, to form a colored species with absorption maxima at 627 nm. The second method is based on the reaction of drug with 1,2 naphthaquinone -4-sulphonic acid sodium salt, under alkaline conditions which absorbs maximally at 454 nm. Beers law is obeyed in the concentration range of 5-25 µg/mL and 2-10 µg/mL respectively. These methods were extended to pharmaceutical formulations and there was no interference from excepients and diluents. The analytical parameters were evaluated.


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