scholarly journals Utility of Certain π-Acceptors for the Spectrophotometric Determination of Hydralazine Hydrochloride

2003 ◽  
Vol 71 (3) ◽  
pp. 179-194
Author(s):  
W. El-Hawary ◽  
A. Shoukry ◽  
A. Talat
Keyword(s):  
Spectrophotometric Determination ◽  
Good Accuracy ◽  
Picric Acid ◽  
Pharmaceutical Preparations ◽  
Detection Limits ◽  
Several Variables ◽  
Accuracy And Precision ◽  
Hydralazine Hydrochloride ◽  
Ml Detection

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.

scholarly journals New Application of Chromotropic Acid for the Determination of Some Sulphonamides in their Pharmaceutical Preparations

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.
Keyword(s):  
Azo Dye ◽  
Good Accuracy ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Extraction Process ◽  
Molar Absorptivity ◽  
Chromotropic Acid ◽  
Time Consumption ◽  
Accuracy And Precision

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.

Selective determination of tantalum in ores by extraction with N-phenylbenzohydroxamic acid in toluene

1990 ◽  
Vol 55 (7) ◽  
pp. 1686-1690 ◽  
Author(s):  
José Aznarez ◽  
Juan Carlos Vidal ◽  
Cecilia Vaquero
Keyword(s):  
Hydrochloric Acid ◽  
Acid Solution ◽  
Aqueous Phase ◽  
Spectrophotometric Determination ◽  
Absorption Maximum ◽  
Good Accuracy ◽  
Molar Absorptivity ◽  
Selective Determination ◽  
Accuracy And Precision

A method for tantalum(V) spectrophotometric determination in a non-aqueous phase is proposed. Tantalum(V) is extracted with N-phenylbenzohydroxamic acid into toluene from a 5M hydrochloric acid solution. The colour is then developed by addition of 4-(2-pyridylazo)-resorcinol (PAR) solution in N,N-dimethylformamide and pyridine to an aliquot of the extracted phase. The Ta(V)-PAR complex gives an absorption maximum at 547 nm with a molar absorptivity of 3.88 ± 0.04 . 104 l mol-1 cm-1. The method has been applied to the selective determination of tantalum in ores with good accuracy and precision.

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 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
Keyword(s):  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Good Accuracy ◽  
Pharmaceutical Formulations ◽  
European Pharmacopoeia ◽  
Accuracy And Precision ◽  
Antihistaminic Drugs ◽  
Assay Conditions ◽  
Sensitive Spectrophotometric Method

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.

scholarly journals Use of Π-Acceptors for Spectrophotometric Determination of Dicyclomine Hydrochloride

2003 ◽  
Vol 86 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Lories I Bebawy ◽  
Yosry M Issa ◽  
Kamal M Abdel Moneim
Keyword(s):  
Spectrophotometric Determination ◽  
Good Accuracy ◽  
Experimental Conditions ◽  
Chloranilic Acid ◽  
Colored Complex ◽  
Complex Species ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Colored Complexes

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.

scholarly journals TITRIMETRIC AND SPECTROPHOTOMETRIC ASSAY OF BUPROPION HYDROCHLORIDE IN PHARMACEUTICALS USING MERCURY(II) NITRATE

2018 ◽  
Vol 35 (3) ◽  
pp. 09
Author(s):  
M. A. Sameer Abdulaziz ◽  
K. Basavaiah ◽  
K. B. Vinay
Keyword(s):  
Good Accuracy ◽  
Pharmaceutical Preparations ◽  
Standard Addition ◽  
Chloride Content ◽  
Bromophenol Blue ◽  
Fixed Amount ◽  
Titrimetric Method ◽  
Accuracy And Precision ◽  
Reaction Stoichiometry

Two simple, rapid and accurate methods for the determination of bupropion hydrochloride (BUP) in pure and in pharmaceutical preparations are described. Both methods are based on the measurement of the chloride of its hydrochloride. In the titrimetric method, the chloride content of bupropion hydrochloride is determined by titrating with mercury(II)nitrate using diphenylcarbazone–bromophenol blue as indicator. Titrimetric method is applicable over a range 2–20 mg of BUP and the reaction stoichiometry is found to be 2:1 (BUP: Hg(NO3)2).The spectrophotometric method involves the addition of a measured excess of mercury(II) nitrate reagent in formate buffer to the drug, and after ensuring the reaction had gone to completion, the unreacted mercury(II) is treated with a fixed amount of diphenylcarbazone, and absorbance measured at 515 nm. The absorbance is found to decrease linearly with increasing concentration of BUP and the calibration curve is linear over 1.0–15.0 μg mL–1 BUP. The proposed methods were successfully applied to the determination of BUP in commerciallyavailable dosage forms with good accuracy and precision, and without  detectable interference by excipients. The accuracy was further ascertained by placebo blank and synthetic mixture analyses and also by recovery experiments via standard-addition procedure.

Extraction-spectrophotometric determination of mefenamic acid in pharmaceutical preparations

2014 ◽  
Vol 69 (10) ◽  
pp. 960-964 ◽  
Author(s):  
Zh. A. Kormosh ◽  
O. Yu. Matviichuk ◽  
Ya. R. Bazel’
Keyword(s):  
Spectrophotometric Determination ◽  
Mefenamic Acid ◽  
Pharmaceutical Preparations

Spectrophotometric Determination of Lignocaine in Pure Form and in Pharmaceutical Preparations

1997 ◽  
Vol 30 (15) ◽  
pp. 2743-2753 ◽  
Author(s):  
M. S. Rizk ◽  
Y M Issa ◽  
A F Shoukry ◽  
E M Atia
Keyword(s):  
Spectrophotometric Determination ◽  
Pharmaceutical Preparations ◽  
Pure Form
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