scholarly journals Spectrophotometric determination of repaglinide in tablets based on charge-transfer complexation reaction with chloranilic acid and dichloro-dicyano benzoquinone

2011 ◽  
Vol 17 (4) ◽  
pp. 469-476 ◽  
Author(s):  
Madathil Cijo ◽  
Kanakapura Basavaiah ◽  
Sameer Abdulrahman ◽  
K.B. Vinay
Keyword(s):  
Charge Transfer ◽  
Correlation Coefficients ◽  
Molar Absorptivity ◽  
Complexation Reaction ◽  
Chloranilic Acid ◽  
Subsequent Formation ◽  
Spectrophotometric Methods ◽  
Bulk Drug ◽  
Charge Transfer Complexation

Two simple, accurate, precise, inexpensive, selective and sensitive spectrophotometric methods are described for the determination of repaglinide (RPG) in bulk drug and its tablets. The methods were based on the charge- transfer complex reaction between RPG in acetonitrile with p-chloranilic acid (CAA) or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in dioxane and subsequent formation of intensely colored radical anions of the reagents which were measured at 520 nm (CAA) or 590 nm (DDQ). Several experimental variables affecting the complex formation, stability of the colored species and sensitivity of the reaction were optimized. Under the optimized conditions, Beer?s law was obeyed over the concentration ranges of 20-400 and 5-80 ?g ml-1 RPG for CAA and DDQ methods, respectively, and the corresponding correlation coefficients were 0.9995 and 0.9998. The apparent molar absorptivity values were 1.02x103 and 4.60x103 for CAA and DDQ methods respectively, with corresponding Sandell sensitivity values of 0.4438 and 0.0984 ?g cm-2. Limits of detection (LOD) were calculated to be 7.07 and 2.42 ?g ml-1 and the limits of quantification (LOQ) were 21.43 and 7.33 ?g ml-1 RPG, for CAA method and DDQ method, respectively. Validation results demonstrated that the inter day and intra day accuracy were up to 97.56%. The precision determined did not exceed 2.5% of RSD. The methods were successfully used for the determination of RPG in tablet form and the results were in good agreement with the label claims as shown by the recoveries which were in the range of 99.22- 102.8% with standard deviation values < 2%. The accuracy of the method was confirmed by recovery studies via standardaddition procedure with excellent recovery 98.24-104.0 ? 1.08-3.35.

scholarly journals Use of Charge Transfer Complexation Reactions for the Spectrophotometric Determination of Sumatriptan in Pharmaceuticals

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Kudige N. Prashanth ◽  
Basavaiah Kanakapura ◽  
Madihalli S. Raghu ◽  
Kanakapura B. Vinay
Keyword(s):  
Charge Transfer ◽  
Correlation Coefficients ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Ct Complex ◽  
Reaction Stoichiometry ◽  
Complexation Reactions ◽  
Charge Transfer Complexation ◽  
Job's Method

Studies were carried out to use the charge-transfer reactions of sumatriptan (SMT), extracted from neutralized sumatriptan succinate (STS), as n-electron donor with the π-acceptor, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and σ-acceptor, and iodine (I2). The formation of the colored complexes was utilized for the development of simple, rapid, and accurate spectrophotometric methods for the determination of SMT in pure form as well as in its tablets. The quantification of colored products was made spectrophotometrically at 585 nm for the CT complex formed between SMT and DDQ (DDQ method) and at 375 nm for the CT complex formed between SMT and I2 (I2 method). Beer’s law is obeyed over the concentration ranges of 4.0–56.0 μg mL−1 and 2.0–28.0 for DDQ and I2, respectively, with correlation coefficients () of 0.9997 and 0.9998. The analytical parameters such as apparent molar absorptivity, Sandell’s sensitivities, and limits of detection (LOD) and quantification (LOQ) are also reported for both methods. The described methods were successfully applied to the determination of SMT in tablets. No interference was observed from the common excipients present in tablets. The reaction stoichiometry in both methods was evaluated by Job’s method of continuous variations and was found to be 1 : 1 (donor : acceptor).

scholarly journals Spectrophotometric Determination of Mycophenolate Mofetil as Its Charge-Transfer Complexes with Twoπ-Acceptors

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
K. B. Vinay ◽  
H. D. Revanasiddappa ◽  
M. S. Raghu ◽  
Sameer. A. M. Abdulrahman ◽  
N. Rajendraprasad
Keyword(s):  
Mycophenolate Mofetil ◽  
Charge Transfer ◽  
Correlation Coefficients ◽  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Charge Transfer Complexes ◽  
Complexation Reaction ◽  
Chloranilic Acid

Two simple, selective, and rapid spectrophotometric methods are described for the determination of mycophenolate mofetil (MPM) in pure form and in tablets. Both methods are based on charge-transfer complexation reaction of MPM with p-chloranilic acid (p-CA) or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in dioxane-acetonitrile medium resulting in coloured product measurable at 520 nm (p-CA) or 580 nm (DDQ). Beer’s law is obeyed over the concentration ranges of 40–400 and 12–120 μg mL−1MPM for p-CA and DDQ, respectively, with correlation coefficients (r) of 0.9995 and 0.9947. The apparent molar absorptivity values are calculated to be1.06×103and3.87×103 L mol−1 cm−1, respectively, and the corresponding Sandell’s sensitivities are 0.4106 and 0.1119 μg cm−1. The limits of detection (LOD) and quantification (LOQ) are also reported for both methods. The described methods were successfully applied to the determination of MPM in tablets. Statistical comparison of the results with those of the reference method showed excellent agreement. No interference was observed from the common excipients present in tablets. Both methods were validated statistically for accuracy and precision. The accuracy and reliability of the methods were further ascertained by recovery studiesviastandard addition procedure.

scholarly journals Utility of p-Chloranilic Acid and 2,3-Dichloro-5,6-dicyano-p-benzoquinone for the Spectrophotometric Determination of Rizatriptan Benzoate

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Kudige N. Prashanth ◽  
Kanakapura Basavaiah
Keyword(s):  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Complexation Reaction ◽  
Chloranilic Acid ◽  
Rizatriptan Benzoate ◽  
Spectrophotometric Methods ◽  
Migraine Headaches ◽  
Charge Transfer Complexation

Rizatriptan is a new selective 5-HT1B/1D agonist which is used in the treatment of migraine headaches. Two simple, rapid, accurate, and economical spectrophotometric methods are described for the determination of rizatriptan benzoate (RTB) in its pure form and pharmaceutical preparations. These methods are based on the charge-transfer complexation reaction between rizatriptan benzoate as n-electron donor and p-chloranilic acid (p-CA) or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as π-acceptor to form highly colored chromogens. The chromogens formed by the reaction between RTB and p-CA peaked at 530 nm (method A) and that formed by the reaction between RTB and DDQ peaked at 590 nm (method B). Under the optimum conditions Beer’s law is obeyed in the concentration range of 14–245 μg mL−1 for method A and 4–70 μg mL−1 for method B. The coefficient of correlation was found to be 0.9999 for both methods. The molar absorptivity, Sandell sensitivity, limits of detection, and quantification are also reported. The stoichiometric relationship determined by Job’s continuous method was found to be 1 : 1 (drug : reagent) for both methods. Both methods were applied to determination of RTB in the pharmaceutical formulations. Results of the analysis were validated statistically.

scholarly journals Spectrophotometric Methods for the Assay of Pyrilamine Maleate Using Chromogenic Reagents

2010 ◽  
Vol 7 (4) ◽  
pp. 1507-1513 ◽  
Author(s):  
V. Annapurna ◽  
G. Jyothi ◽  
V. Nagalakshmi ◽  
B. B. V. Sailaja
Keyword(s):  
Charge Transfer ◽  
Oxidative Coupling ◽  
Coupling Reaction ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Method Of Least Squares ◽  
Spectrophotometric Methods ◽  
Oxidative Coupling Reaction ◽  
Charge Transfer Complexation

Simple, accurate and reproducible UV spectrophotometric methods were established for the assay of pyrilamine maleate (PYRA) based on the formation of oxidative coupling and precipitation, charge transfer complexation products. Method A includes the oxidative coupling reaction of PYRA with 3-methyl-2-benzathiazolinone hydrazone (MBTH) in presence of Ce(IV). The formation of oxidative coupling product with 4-amino phenazone (4-AP) in presence of K3Fe(CN)6is incorporated in method B. Precipitation/charge transfer complex formation of the PYRA with tannic acid (TA)/Metol-Cr(VI) in method C were proposed. The optical characteristics such as Beers law limits, molar absorptivity and Sandell’s sensitivity for the methods (A-C) are given. Regression analysis using the method of least squares was made to evaluate the slope (b), intercept (a) and correlation coefficient (r) and standard error of estimation (Se) for each system. Determination of pyrilamine in bulk form and in pharmaceutical formulations were also incorporated.

scholarly journals Two charge-transfer complex spectrophotometric methods for the determination of sulpiride in pharmaceutical formulations

2009 ◽  
Vol 7 (4) ◽  
pp. 870-875 ◽  
Author(s):  
Sayed Zayed
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Complex ◽  
Standard Free Energy ◽  
Pharmaceutical Formulations ◽  
Association Constants ◽  
Official Method ◽  
Chloranilic Acid ◽  
Spectrophotometric Methods ◽  
Charge Transfer Complexation

AbstractTwo simple, rapid, accurate and sensitive spectrophotometric methods are described for the determination of sulpiride. They are based on charge transfer complexation between the drug as n-electron donor and p-chloranilic acid as π acceptor or iodine as σ-acceptor. These give highly coloured complexes with absorption maxima at 518 and 363, 294 nm, respectively. Beer’s law linear ranges were 13.7–341.4 and 1.7–20.5 µg mL−1 for the p-chloranilic acid and iodine methods. The methods were successfully applied to the determination of the drug in Dogmatil® Fort tablets and the results compared with the official method. The complex association constants and standard free energy changes were calculated using Benesi-Hildebrand plots.

scholarly journals Optimized and validated spectrophotometric methods for the determination of hydroxyzine hydrochloride in pharmaceuticals and urine using iodine and picric acid

2011 ◽  
Vol 76 (11) ◽  
pp. 1551-1560 ◽  
Author(s):  
Nagaraju Rajendraprasad ◽  
Kanakapura Basavaiah ◽  
Kanakapura Vinay
Keyword(s):  
Human Urine ◽  
Picric Acid ◽  
Cost Effective ◽  
Molar Absorptivity ◽  
Complexation Reaction ◽  
Spectrophotometric Methods ◽  
Charge Transfer Complexation ◽  
Spiked Human Urine ◽  
Acceptor Method

Two simple, rapid, cost-effective and sensitive spectrophotometric procedures are proposed for the determination of hydroxyzine dihydrochloride (HDH) in pharmaceuticals and in spiked human urine. The methods are based on the charge transfer complexation reaction of the drug with either iodine (I2) as a ?-acceptor (method A) in dichloromethane or picric acid (PA) as a ?-acceptor (method B) in chloroform. The coloured products exhibit absorption maxima at 380 and 400 nm for I2 and PA, respectively. The Beer Law was obeyed over the concentration ranges of 1.25-15 and 3.75-45 ?g mL-1 for method A and method B, respectively. The molar absorptivity values, Sandell sensitivities, limits of detection (LOD) and quantification (LOQ) are reported. The accuracy and precision of the methods were evaluated on intra-day and inter-day basis. The proposed methods were successfully applied for the determination of HDH in tablets and spiked human urine.

scholarly journals Utility of σ and π-Acceptors for the Spectrophotometric Determination of Gemifloxacin Mesylate in Pharmaceutical Formulations

2008 ◽  
Vol 5 (3) ◽  
pp. 493-498 ◽  
Author(s):  
Marothu Vamsi Krishna ◽  
Dannana Gowri Sankar
Keyword(s):  
Charge Transfer ◽  
Good Accuracy ◽  
Pharmaceutical Formulations ◽  
Charge Transfer Complexes ◽  
Complexation Reaction ◽  
Experimental Conditions ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Charge Transfer Complexation

In this study, four simple, fast, accurate and sensitive spectrophotometric methods have been developed for the determination of gemifloxacin mesylate in pharmaceutical formulations. The methods are based on the charge transfer complexation reaction of the drug as n-electron donor with sigma (σ)-acceptor iodine, and thepi(π)-acceptors 2, 3-dichloro-5, 6-dicyano-p-benzoquinone (DDQ)-7,7,8,8-tetra cyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE). The obtained charge transfer complexes were measured at 290nm for iodine (in 1, 2-dichloro ethane), at 470, 840 and 420 nm for DDQ, TCNQ and TCNE (in acetonitrile), respectively. Optimization of different experimental conditions is described. Beer's law is obeyed in the concentration range of 6-30, 2-10, 2.5-12.5 and 1-5 μg mL−1for iodine, DDQ, TCNQ and TCNE methods, respectively. The proposed methods were applied successfully to the determination of GFX in pharmaceutical formulations with good accuracy and precision.

scholarly journals Simple and rapid spectrophotometric assay of albendazole in pharmaceuticals using iodine and picric acid as CT complexing agents

2014 ◽  
Vol 50 (4) ◽  
pp. 839-850 ◽  
Author(s):  
Nagaraju Swamy ◽  
Kanakapura Basavaiah
Keyword(s):  
Picric Acid ◽  
Molar Absorptivity ◽  
Complexing Agents ◽  
Complexation Reaction ◽  
Experimental Conditions ◽  
Spectrophotometric Methods ◽  
Bulk Drug ◽  
Ct Complexes ◽  
Acceptor Method

Two simple, rapid and inexpensive spectrophotometric methods are described for the determination of albendazole (ALB) in bulk drug and in tablets. The methods are based on charge-transfer (CT) complexation reaction involving ALB as n-donor and iodine as σ-acceptor (method A) in dichloromethane or picric acid (PA) as π-acceptor (method B) in chloroform. The absorbance of CT complexes was measured at 380 nm for method A, and 415 nm for method B. The optimization of the experimental conditions is described. Under optimum conditions, Beer's law obeyed over the concentration ranges 8.0-240 and 2.4-42 μg mL-1 for method A and method B, respectively. The apparent molar absorptivity of CT complexes at the respective λmax are calculated to be 1.17×103 and 5.22×103 L mol-1cm-1 respectively, and the corresponding Sandell sensitivity values are 0.2273 and 0.0509 ng cm-2. The limits of detection (LOD) and quantification (LOQ) are calculated to be (0.69 and 2.08), and (0.10 and 0.30) μg mL-1 with method A, and method B, respectively. The intra-day and inter-day accuracy expressed as % RE and precision expressed as % RSD were less than 3%. The methods were applied to the determination of ALB in tablets.

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