scholarly journals Spectrophotometric Determination of Some Antihistaminic Drugs Using 7,7,8,8-Tetracyanoquinodimethane (TCNQ)

2006 ◽  
Vol 89 (1) ◽  
pp. 46-52 ◽  
Author(s):  
Amr M Badawey ◽  
Samah S Abbas ◽  
Hayam M Loutfy

Abstract A simple and sensitive spectrophotometric method is suggested for analysis of 3 antihistaminic drugs, acrivastine (I), mequitazine (II), and dimethindene maleate (III). The method is based on reaction of the drugs with 7,7,8,8-tetracyanoquinodimethane (TCNQ) in acetonitrile to form highly stable colored products that are measured at 750, 766, and 844 nm for I and II, and 480 and 618 nm for III. Beer's law is obeyed in the ranges of 560 g/mL for I, 550 g/mL for II, and 1070 g/mL for III. The optimum assay conditions and their applicability to the determination of the cited drugs in pharmaceutical formulations are described. The method is statistically analyzed as compared with the European Pharmacopoeia (2001) method for the analysis of dimethindene maleate and reference methods for acrivastine and mequitazine drugs revealing good accuracy and precision.

2009 ◽  
Vol 6 (s1) ◽  
pp. S163-S170 ◽  
Author(s):  
R. Singh Gujral ◽  
S. Manirul Haque ◽  
P. Shanker

An accurate and validated spectrophotometric method was developed for the determination of gabapentin. This is simple, sensitive and low cost UV spectrophotometric method. The method is based on the direct measurement of the native absorbance of the drug. The detection was done at 210 nm. The method was linear in the range of 0.25 - 3.5 µ g/mL with correlation coefficient of 0.9999. It is validated according to the ICH guidelines with respect to linearity, selectivity, accuracy and precision, limit of quantitation and limit of detection. The method has been applied to assess gabapentin in pharmaceutical formulations with good accuracy and precision and relatively free of interference from coexisting substances.


2009 ◽  
Vol 6 (1) ◽  
pp. 89-92 ◽  
Author(s):  
Alka Gupta ◽  
P. Mishra ◽  
K. Shah

A new, simple and sensitive spectrophotometric method in ultraviolet region has been developed for the determination of rosuvastatin calcium in bulk and in pharmaceutical formulations. Rosuvastatin exhibits absorption maxima at 244 nm with apparent molar absorptivity of 7.2345 ×104L/mol.cm in methanol. Beer’s law was found to be obeyed in the concentration range of 2-18 µg/mL. The method is accurate, precise and economical. This method is extended to pharmaceutical preparations. In this method, there is no interference from any common pharmaceutical additives and diluents. Results of the analysis were validated statistically and by recovery studies


2010 ◽  
Vol 7 (3) ◽  
pp. 785-788 ◽  
Author(s):  
Mohammad Yunoos ◽  
D. Gowri Sankar ◽  
B. Pragati Kumar ◽  
Shahul Hameed ◽  
Azmath Hussain

A new, simple and sensitive spectrophotometric method in ultraviolet region has been developed for the determination of duloxetine hydrochloride in bulk and in pharmaceutical formulations. Duloxetine hydrochloride exhibits absorption maxima at 288 nm with apparent molar absorptivity of 0.97x104L/mol.cm in 0.1 N HCL. Beer's law was found to be obeyed in the concentration range of 5-30 μg/mL. The method is accurate, precise and economical. The proposed method has been applied successfully for the analysis of the drug in pure and in its capsule dosage forms. In this method, there is no interference from any common pharmaceutical additives and diluents. Results of the analysis were validated statistically and by recovery studies.


2013 ◽  
Vol 10 (3) ◽  
pp. 965-970
Author(s):  
Baghdad Science Journal

A simple, rapid and sensitive spectrophotometric method has been developed for the determination of captopril in aqueous solution. The method is based on reaction of captopril with 2,3-dichloro 1,4- naphthoquinon(Dichlone) in neutral medium to form a stable yellow colored product which shows maximum absorption at 347 nm with molar absorptivity of 5.6 ×103 L.mole-1. cm-1. The proposed method is applied successfully for determination of captopril in commercial pharmaceutical tablets.


2011 ◽  
Vol 8 (1) ◽  
pp. 110-117 ◽  
Author(s):  
Baghdad Science Journal

A simple, accurate and sensitive spectrophotometric method for the determinaion of epinephrine is described . The method is based on the coordination of Pr (III) with epinephrine at pH 6. Absorbance of the resulting orange yellow complex is measured at 482 nm . A graph of absorbance versus concentrations shows that beer 's low is obeyed over the concentration range (1-50)mg.ml-1 of epinephrine with molar absorpitivity of ( 2.180x103 L.mol-1.cm-1 ), a sandell sensitivity of (0.084 mg.cm-2 ), a relative error of (-2.83%) , a corrolation coffecient (r= 0.9989) and recovery % ( 97.03 ± 0.75 ) depending on the concentration.This method is applied to analyse EP in several commercially available pharmaceutical preparations using direct methods .All statistical calculations are implemented via a Minitab software version 11.


2008 ◽  
Vol 33 (3) ◽  
pp. 7-12 ◽  
Author(s):  
M. A. Gotardo ◽  
L. S. Lima ◽  
R. Sequinel ◽  
J. L. Rufino ◽  
L. Pezza ◽  
...  

A simple, rapid and sensitive spectrophotometric method has been developed for the determination of methyldopa in pharmaceutical formulations. The method is based on the reaction between tetrachloro-p-benzoquinone (p-chloranil) and methyldopa, accelerated by hydrogen peroxide (H2O2), producing a violet-red compound (λmax = 535 nm) at ambient temperature (25.0 ± 0.2 ºC). Experimental design methodologies were used to optimize the measurement conditions. Beer's law is obeyed in a concentration range from 2.10 x 10-4 to 2.48 x 10-3 mol L-1 (r = 0.9997). The limit of detection was 7.55 x 10-6 mol L-1 and the limit of quantification was 2.52 x 10-5 mol L-1. The intraday precision and interday precision were studied for 10 replicate analyses of 1.59 x 10-3 mol L-1 methyldopa solution and the respective coefficients of variation were 0.7 and 1.1 %. The proposed method was successfully applied to the determination of methyldopa in commercial brands of pharmaceuticals. No interferences were observed from the common excipients in the formulations. The results obtained by the proposed method were favorably compared with those given by the Brazilian Pharmacopoeia procedure at 95 % confidence level.


2021 ◽  
Vol 2063 (1) ◽  
pp. 012008
Author(s):  
S A Zakaria ◽  
R A Zakaria ◽  
N S Othman

Abstract A selective and sensitive spectrophotometric method has been suggested for the quantitative assay of atenolol (ATNL) as pure and in its manufactural formulation(Tablet). The suggested procedure included oxidation of ATNL with an excess quantity of the oxidant N-bromosuccinimide (NBS), and then the excess of NBS was occupied in bleaching the color of methyl red dye(MRD), then measuring the absorbance of remaining MRD at 518 nm. The absorbance of the unbleached color of MRD corresponds to the ATNL concentration in the sample solution. Beer’s law was followed in the range of 0.1-2.0 μg.ml−1with molar absorptivity value equal to 8.8864x104 l.mol−1. cm−1. The suggested method was applied to the assay of ATNL in commercial tablets, with satisfactory results.


1993 ◽  
Vol 76 (3) ◽  
pp. 601-603 ◽  
Author(s):  
A A Al-Warthan ◽  
S S Al-Showiman ◽  
S A Al-Tamrah ◽  
A A BaOsman

Abstract The formation of a red complex between boron and the quinalizarin reagent was investigated and used as the basis for a simple and sensitive spectrophotometric method for boron in date cultivars. At 620 nm, the absorbance was linear (r= 0.999) over the 0.25-2.5 μg/mL concentration range. The molar absorptivity was found to be 2.23 x 103mol-1cm-1 and the relative standard deviation for 10 replicates (1.0 μg/mL) was 0.97%.


2003 ◽  
Vol 71 (3) ◽  
pp. 179-194
Author(s):  
W. El-Hawary ◽  
A. Shoukry ◽  
A. Talat

The interaction of hydralazine hydrochloride with picric acid (I), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) (II), 2,4-dinitrobenzoic acid (III), bromanil (IV) and chloranil (V) was found to be useful for its spectrophotometric determination. The determination was carried out at 520, 510, 550, 540 and 535 nm for the reaction with (I), (II), (III), (IV) and (V), respectively. The effect of several variables on the colouring process was studied. The proposed methods have been applied successfully for the determination of hydralazine hydrochloride in pure samples and in pharmaceutical preparations with good accuracy and precision. The results were compared to those obtained by the official and pharmacopoeia1 methods. The linear ranges for obedience of Beer's law are up to 118, 54,639, 27.5 and 78.6 mg/l, Ringbom ranges are 13-100, 7.6-44.7, 77.4-445.0, 5.8-25.8 and 22.5-63.1 μg/ml, Detection limits are 4.8, 2.2, 18.4, 1.2 and 5.9 mg/l, and RSD 0.042, 0.037, 0.043, 0.013 and 0.073 for reactions of hydralazine hydrochloride with I, II, III, IV and V, respectively.


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