scholarly journals Spectrophotometric Determination of Doxazosin Mesylate in Tablets by Ion-Pair and Charge-Transfer Complexation Reactions

2009 ◽  
Vol 92 (1) ◽  
pp. 131-137 ◽  
Author(s):  
Zeynep Aydomu ◽  
Asli Barla
Keyword(s):  
Charge Transfer ◽  
Ion Pair ◽  
Bromophenol Blue ◽  
Bromocresol Purple ◽  
Charge Transfer Reaction ◽  
Accuracy And Precision ◽  
Doxazosin Mesylate ◽  
Significant Difference ◽  
Complexation Reactions

Abstract Two accurate, easy spectrophotometric methods for the determination of doxazosin mesylate were described. The first method was based on the formation of ion-pair complexes with the acidic sulfophthalein dyes bromocresol purple (BCP) and bromophenol blue (BPB) in pH 3.3 and 4.5 citratephosphate buffer, respectively. The formed complexes were extracted into dichloromethane, and their absorbance was measured at 403 and 410 nm for BCP and BPB, respectively. The second method was based on the charge transfer reaction of the drug as an n-electron donor with either 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) or 7,7,8,8-tetracyanoquinodimethane (TCNQ) as -acceptors, to give colored radical anions. The absorbances of products were measured at 457 nm in acetonitrile and 838 nm in methanol for DDQ and TCNQ, respectively. Under the optimum reaction conditions, Beer's law was obeyed with a good correlation coefficient (r = 0.99970.9999) in the concentration ranges 3.018.0, 3.020.0, 15.095.0, and 10.0100.0 g/mL for the BCP, BPB, DDQ, and TCNQ methods, respectively. Limits of detection of the BCP, BPB, DDQ, and TCNQ methods were 0.314, 0.408, 1.935, and 1.610 g/mL, respectively. The limits of quantification were 1.045, 1.360, 6.449, and 5.367 g/mL, respectively. The parameters molar absorptivity, precision, accuracy, recovery, robustness, and stability constant were studied. The proposed methods were successfully applied for determination of the drug in tablets with good accuracy and precision. Statistical comparison of the results with those obtained by a reported method showed good agreement and indicated no significant difference in accuracy and precision.

scholarly journals Spectrophotometric determination of dothiepin hydrochloride in pharmaceuticals through ion-pair complexation reaction

2012 ◽  
Vol 18 (2) ◽  
pp. 339-347 ◽  
Author(s):  
Sameer Abdulrahman ◽  
Kanakapura Basavaiah
Keyword(s):  
Ion Pair ◽  
Pure Form ◽  
Bromocresol Green ◽  
Bromophenol Blue ◽  
Complexation Reaction ◽  
Conditional Stability ◽  
Conditional Stability Constant ◽  
Accuracy And Precision ◽  
Significant Difference

Two simple, sensitive and extraction-free spectrophotometric methods are described for the determination of dothiepin hydrochloride (DOTH) both in pure form and in pharmaceutical tablets. The methods are based on ion-pair complex formation between dothiepin base (DOT) and two acidic dyes, namely, bromophenol blue (BPB) or bromocresol green (BCG) with absorption maximum at 425 nm for BPB method or 430 nm for BCG method. Beer?s law is obeyed over the concentration ranges of 1.0-15.0 and 1.0-17.5 ?g mL-1 DOT for BPB and BCG methods, respectively. The molar absorptivity values and Sandell?s sensitivity values are reported for both methods. The limits of detection (LOD) and quantification (LOQ) were calculated to be 0.18 and 0.53 ?g mL-1 for BPB method, and 0.17 and 0.50 ?g mL-1 for BCG method, respectively. The stoichiometry of the complex in either case was found to be 1: 1 and the conditional stability constant (KF) of the complexes has also been calculated. The proposed methods were applied successfully to the determination of DOTH in pure form and in its tablet form with good accuracy and precision. Statistical comparison of the results was performed using Student's t-test and variance ratio F-test at 95% confidence level and there was no significant difference between the official and proposed methods with regard to accuracy and precision. Further, the validity of the proposed methods was confirmed by recovery studies via standard addition technique.

scholarly journals DEVELOPMENT AND VALIDATION OF NEW SPECTROPHOTOMETRIC METHODS FOR ESTIMATION OF ANTIPSYCHOTIC DRUG ASENAPINE MALEATE IN PURE AND DOSAGE FORMS

2020 ◽  
pp. 62-69
Author(s):  
RAGAA EL-SHEIKH ◽  
AHLAM E. ABD ELLATEIF ◽  
ESRAA AKMAL ◽  
AYMAN A. GOUDA
Keyword(s):  
Limit Of Detection ◽  
Dosage Forms ◽  
Ion Pair ◽  
Stoichiometric Ratio ◽  
Bromocresol Purple ◽  
Pharmaceutical Dosage Forms ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Significant Difference

Objective: Three sensitive, simple, precise, reproducible, and validated spectrophotometric methods have been developed for the determination of anti-psychotic drug (asenapine maleate) in pure and pharmaceutical dosage forms. Methods: The methods are based on the formation of yellow-colored ion-pair complex between asenapine maleate and three acid dyes, namely, bromocresol purple (BCP), bromophenol blue (BPB) and bromothymol blue (BTB) with absorption maxima at 410, 414 and 416 nm, respectively. Several parameters such as pH, buffer type and volume, reagent volume, the sequence of addition and effect of extracting solvent were optimized. Results: Under the optimum experimental conditions, beer’s law is obeyed over the concentration ranges of 1.0–20, 1.0–14, and 1.0-16 μg/ml for BCP, BPB and BTB, respectively, with good correlation coefficients (0.9994-0.9998). The apparent molar absorptivity and Sandell’s sensitivity values are reported for all methods. The limit of detection (LOD) and the limit of quantification (LOQ) values are found to be 0.27, 0.30, and 0.25 μg/ml and 0.90, 1.0, and 0.83 μg/ml for BCP, BPB and BTB, respectively. The stoichiometric ratio of the formed ion-pair complexes was found to be 1:1 (drug: reagent) for all methods, as deduced by Job's method of continuous variation. Conclusion: The proposed methods were successfully applied for the determination of asenapine maleate in pharmaceutical formulations with good accuracy and precision. Statistical comparison of the results was performed using Student's t-test and variance ratio F-test at the 95% confidence level and there was no significant difference between the reported and proposed methods regarding accuracy and precision. Further, the validity of the proposed methods was confirmed by recovery studies via standard addition technique in accordance with ICH guidelines.

scholarly journals Spectrophotometric Determination of Thioridazine Hydrochloride in Tablets and Biological Fluids by Ion-Pair and Oxidation Reactions

2012 ◽  
Vol 27 ◽  
pp. 129-141 ◽  
Author(s):  
Akram El-Didamony ◽  
Sameh Hafeez
Keyword(s):  
Methylene Chloride ◽  
Biological Fluids ◽  
Indigo Carmine ◽  
Ion Pair ◽  
Bromocresol Green ◽  
Official Method ◽  
Bromocresol Purple ◽  
Accuracy And Precision ◽  
Significant Difference

Two simple, sensitive and selective spectrophotometric methods have been described for the determination of the psychoactive drug, thioridazine HCl in tablets and in biological fluids. The first method is based on the oxidation of thioridazine HCl with measured excess of KMnO4under acidic conditions followed by the determination of unreacted oxidant using indigo carmine and methyl orange. The second method is based on the formation of ion-pair complexes with the acidic sulphophthalein dyes such as bromocresol green and bromocresol purple at pH 1.8 of KCl-HCl buffer. The formed complexes were extracted into methylene chloride and their absorbance was measured at 412 nm. Optimizations of the different experimental conditions are described for both methods. The proposed methods were successfully applied for determination of the drug in tablets and biological fluids with good accuracy and precision. Statistical comparison of the results with those obtained by an official method showed good agreement and indicated no significant difference in accuracy and precision.

scholarly journals Spectrophotometric Determination of Gemifloxacin Mesylate, Moxifloxacin Hydrochloride, and Enrofloxacin in Pharmaceutical Formulations Using Acid Dyes

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Ayman A. Gouda ◽  
Alaa S. Amin ◽  
Ragaa El-Sheikh ◽  
Amira G. Yousef
Keyword(s):  
Pharmaceutical Formulations ◽  
Bromothymol Blue ◽  
Bromocresol Green ◽  
Bromophenol Blue ◽  
Bromocresol Purple ◽  
Acid Dyes ◽  
Spectrophotometric Methods ◽  
Significant Difference ◽  
Comparison Of The Results

Simple, rapid, and extractive spectrophotometric methods were developed for the determination of some fluoroquinolones antibiotics: gemifloxacin mesylate (GMF), moxifloxacin hydrochloride (MXF), and enrofloxacin (ENF) in pure forms and pharmaceutical formulations. These methods are based on the formation of ion-pair complexes between the basic drugs and acid dyes, namely, bromocresol green (BCG), bromocresol purple (BCP), bromophenol blue (BPB), bromothymol blue (BTB), and methyl orange (MO) in acidic buffer solutions. The formed complexes were extracted with chloroform and measured at 420, 408, 416, 415, and 422 nm for BCG, BCP, BPB, BTB, and MO, respectively, for GMF; at 410, 415, 416, and 420 nm for BCP, BTB, BPB, and MO, respectively, for MXF; and at 419 and 414 nm for BCG and BTB, respectively, in case of ENF. The analytical parameters and their effects are investigated. Beer’s law was obeyed in the ranges 1.0–30, 1.0–20, and 2.0–24 μg mL−1for GMF, MXF, and ENF, respectively. The proposed methods have been applied successfully for the analysis of the studied drugs in pure forms and pharmaceutical formulations. Statistical comparison of the results with the reference methods showed excellent agreement and indicated no significant difference in accuracy and precision.

scholarly journals Spectrophotometric determination of some pharmaceutical piperazine derivatives by charge-transfer and ion-pair complexation methods

2002 ◽  
Vol 70 (3) ◽  
pp. 253-269 ◽  
Author(s):  
Issa Y.M. ◽  
Abou-Attia F.M. ◽  
Abdel-Gawad F.M. ◽  
Abdel-Hamid S.M.
Keyword(s):  
Charge Transfer ◽  
Ion Pair ◽  
Bromocresol Green ◽  
Basic Drug ◽  
Yellow Colour ◽  
Piperazine Derivatives ◽  
Relative Standard ◽  
Coloured Complex ◽  
Complexation Reactions

Simple and sensitive spectropliotometric methods are described for the assay of three piperazine derivatives ketoconazole, trimetazidine hydrochloride and piribedil based on cliarge-transfer and ion-pair complexation reactions. The first method is based on the reaction of the basic drug with iodine as o-acceptor in dry 1,2-dichloroethane to form a yellow colour due to the formation of charge-transfer complex showing maximum absorbence at 363, 364 and 359 nm for ketoconazole, trimetazidine hydrochlorid and piribedil, respectively. The second method is based on the reaction of basic drug with bromocresol green (BCG) in dry 1,2- dichloroethane to form a stable yellow coloured complex with maximum absorbance at 407, 408 and 410 nm for ketoconazol, trimetazidine hydrochloride and piribedil, respectively. Beer's law was obeyed for both methods and the relative standard deviations were found to be less than 1%. The two methods can be applied for the analysis of tablets and cream, with no evidence of interference from excipients. A more detailed investigation of the complex was made with respect to its composition association constant and free energy cliange.

scholarly journals Spectrophotometric determination of tadalafil in pure and dosage forms

2011 ◽  
Vol 17 (2) ◽  
pp. 125-132 ◽  
Author(s):  
Kaf Al ◽  
Ayman Gouda
Keyword(s):  
Ion Pairs ◽  
Dosage Forms ◽  
Ion Pair ◽  
Bromocresol Purple ◽  
Buffer Solution ◽  
Spectrophotometric Methods ◽  
Basic Nitrogen ◽  
Accuracy And Precision ◽  
Tablet Dosage

Two simple, rapid, and extractive spectrophotometric methods were developed for the determination of tadalafil (TDF) in both pure and tablet dosage form. These methods are based on the formation of ion-pair complexes between the basic nitrogen of the drug with bromocresol purple (BCP) and methyl orange (MO) in acidic buffer solution. The formed complexes were extracted with chloroform and measured at 410 and 425 nm using BCP and MO, respectively. Beer?s law was obeyed in the range 2.0-20 ?g mL?1 with correlation coefficient (n = 6) ? 0.9996. The molar absorpitivity, Sandell sensitivity, detection and quantification limits were also calculated. The composition of the ion pairs was found 1:1 by Job?s method. The proposed methods have been applied successfully for the analysis of TDF in pure and in its dosage forms. These developed methods were validated for accuracy and precision.

scholarly journals Spectrophotometric Determination of Trimebutine Through Ion- Pair and Charge- Transfer Complexation Reactions

2002 ◽  
Vol 70 (4) ◽  
pp. 341-351 ◽  
Author(s):  
Khalil Shaban M.
Keyword(s):  
Charge Transfer ◽  
Bromothymol Blue ◽  
Ion Pair ◽  
Bromocresol Green ◽  
Bromophenol Blue ◽  
Basic Drug ◽  
Yellow Colour ◽  
Spectrophotometric Methods ◽  
Relative Standard ◽  
Complexation Reactions

Summary Two simple and sensitive spectrophotometric methods are described for the assay of trimebutine. The first method is based on the interaction of the basic drug in 1,2 dichloroethane with bromocresol green (BCG); bromophenol blue (BPB) and bromothymol blue (BTB) in the same solvent to produce a stable yellow ion-pair complexes , which absorbed at 410,406 and 405nm, respectively. The second method is based upon the interaction of the basic drug with iodine in 1,2 dichloroethane. The yellow colour formed due to the formation of charge-transfer complex showed two maxima absorbed at 292 and 362 nm. Beer's law obeyed for both methods and the relative standard deviations were found to be less than 1 %. The two methods can be applied to the analysis of tablets, with no evidence of interference from excipients. A more detailed investigation on the complex was made to its composition, association constant and free energy change.

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