scholarly journals Analytical Study for the Charge-Transfer Complexes of Risperidone in Pure and Dosage Forms

2016 ◽  
Vol 8 (3) ◽  
pp. 1745-1753
Author(s):  
F. Ibrahim ◽  
N. El-Enany ◽  
Sh. Shalan ◽  
Rasha Mostafa Elsharawy
Keyword(s):  
Charge Transfer ◽  
Reaction Pathway ◽  
Pharmaceutical Preparations ◽  
Comparison Method ◽  
Charge Transfer Complexes ◽  
Chloranilic Acid ◽  
Spectrophotometric Methods ◽  
Ich Guidelines ◽  
Optimum Reaction ◽  
Recovery Percentage

Two simple, accurate and sensitive spectrophotometric methods were carried out to investigate through charge-transfer reactions of risperidone (RIS) as n-electron donor with various π acceptors: 7, 7, 8, 8-tetracyanoquinodimethane (TCNQ) and p-chloranilic acid (pCA). The absorbance of reaction product was measured at 842 and 520 nm for TCNQ and pCA reagents respectively. Different experimental parameters affecting the reactions were carefully studied. The reaction pathway was postulated. The proposed spectrophotometric method was utilized for the analysis of RIS in pure form as well as in its pharmaceutical preparations. Under the optimum reaction conditions, Beer’s law is obeyed over the concentration range of 1-12 µg mL-1 and 10-180 µg mL-1 for TCNQ and pCA respectively. The limit of assays detection (LOD) is 0.114 µg mL-1 and 2.55 µg mL-1 for TCNQ and pCA respectively. The mean recovery percentage was 99.72 ± 1.06 and 100.50 ± 1.07 for TCNQ and pCA respectively. The results were compared favorably with those obtained by comparison method. The proposed method was validated statistically according to ICH guidelines.

scholarly journals Analytical Study for the Charge-Transfer Complexes of Pregabalin

2009 ◽  
Vol 6 (2) ◽  
pp. 332-340 ◽  
Author(s):  
Hesham Salem
Keyword(s):  
Charge Transfer ◽  
Pharmaceutical Preparation ◽  
Correlation Coefficients ◽  
Charge Transfer Complexes ◽  
Chloranilic Acid ◽  
Spectrophotometric Methods ◽  
Linear Relationships ◽  
Accuracy And Precision ◽  
Optimum Reaction ◽  
First Time

Studies were carried out, for the first time, to investigate the charge-transfer reactions of Pregabalin (PRE) asn-electron donor with various π-acceptors: 7,7,8,8-tetracyanoquinodimethane (TCNQ), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (chloranilic acid,pCA), tetracyanoethylene (TCNE) and 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil). Different colored charge-transfer complexes and radical anions were obtained. Different variables affecting the reactions were studied and optimized. The formations of the colored complexes were utilized in the development of simple, rapid and accurate spectrophotometric methods for the analysis of PRE in pure form as well as in its pharmaceutical preparation. Under the optimum reaction conditions, linear relationships with good correlation coefficients (0.9995-0.9999) were found between the absorbance and the concentrations of PRE in the range of 8-400 µg mL-1. The limits of assays detection ranged from 0.60 to 8.11 µg mL-1. No interference could be observed from the additives commonly present in the capsules. The methods were successfully applied to the analysis of capsules that contain PRE, with good accuracy and precision; the recovery percentages ranged from 100.19±0.83 to 100.50±0.53. The results were compared favorably with the reported method.

scholarly journals CHARGE-TRANSFER COMPLEXES OF CHLORPHENOXAMINE HYDROCHLORIDE WITH CHLORANILIC ACID, 2,3-DICHLORO-5,6-DICYANO-1,4-BENZOQUINONE AND 7,7,8,8-TETRACYANOQUINODIMETHANE AS π-ACCEPTORS

2019 ◽  
pp. 117-123
Author(s):  
AKRAM M. EL-DIDAMONY ◽  
MOUNIR Z. SAAD ◽  
GEHAD M. RAMADAN
Keyword(s):  
Charge Transfer ◽  
Limit Of Detection ◽  
Standard Free Energy ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Charge Transfer Complexes ◽  
Reaction Products ◽  
Chloranilic Acid ◽  
Accuracy And Precision ◽  
Ct Complex

Objective: To develop simplified, accurate and precise visible spectrophotometric strategies for the assay of chlorphenoxamine hydrochloride (CPX) in pure drug and in its pharmaceutical preparations. Methods: The described methods depended on the formation of charge-transfer (CT) complexes of intense color between CPX as donor with three π-acceptors, chloranilic acid (CLA), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), and 7,7,8,8-tetracyanoquinodimethane (TCNQ) and the colored reaction products were estimated spectrophotometrically at 520 nm, 460 nm and 840 nm for CLA, DDQ, and TCNQ complexes, individually. All the optimum conditions were established. The proposed methods were validated in term of linearity, limit of detection as per the international conference on harmonization guidelines ICH Q2 (R1). Results: The complexes obeyed Beer’s law in the concentration range of 16-144, 6-54 and 4-76 μg/mlwith molar absorptivity at 0.30×104, 0.68×104 and 0.58×104 l/mol/cm for CLA, DDQ, and TCNQ, individually. According to Benesi-Hildebrand plots, the association constants and changes of standard free energy were determined. 1:1 was the ratio of composition of the formed CT-complex. Conclusion: The obtained results revealed that the developed method can be applied successfully for the determination of CPX in drug formulations samples with good accuracy and precision.

scholarly journals Use of the Charge Transfer Reactions for the Spectrophotometric Determination of Risperidone in Pure and in Dosage Forms

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Hemavathi Nagaraju Deepakumari ◽  
Hosakere Doddarevanna Revanasiddappa
Keyword(s):  
Charge Transfer ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Charge Transfer Complexes ◽  
Chloranilic Acid ◽  
Colored Complex ◽  
Relative Standard ◽  
Complexation Reactions

The aim of study was to develop and validate two simple, sensitive, and extraction-free spectrophotometric methods for the estimation of risperidone in both pure and pharmaceutical preparations. They are based on the charge transfer complexation reactions between risperidone (RSP) as n-electron donor and p-chloranilic acid (p-CA) in method A and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in method B as π-acceptors. In method A, RSP reacts with p-CA in methanol to produce a bright pink-colored chromogen measured at 530 nm whereas, in method B, RSP reacts with DDQ in dichloromethane to form orange-colored complex with a maximum absorption at 460 nm. Beer's law was obeyed in the concentration range of 0–25 and 0–50 μg/mL with molar absorptivity of and L/moL/cm for RSP in methods A and B, respectively. The effects of variables such as reagents, time, and stability of the charge transfer complexes were investigated to optimize the procedures. The proposed methods have been successfully applied to the determination of RSP in pharmaceutical formulations. Results indicate that the methods are accurate, precise, and reproducible (relative standard deviation %).

scholarly journals Charge Transfer Complexes of Ketotifen with 2,3-Dichloro-5,6-dicyano-p-benzoquinone and 7,7,8,8-Tetracyanoquodimethane: Spectroscopic Characterization Studies

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2039
Author(s):  
Gamal A. E. Mostafa ◽  
Ahmed Bakheit ◽  
Najla AlMasoud ◽  
Haitham AlRabiah
Keyword(s):  
Charge Transfer ◽  
Spectroscopic Characterization ◽  
Molar Ratio ◽  
Charge Transfer Complexes ◽  
Physical Parameters ◽  
Spectrophotometric Methods ◽  
Theoretical Approaches ◽  
The Stability ◽  
Ct Complexes

The reactions of ketotifen fumarate (KT) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π acceptors to form charge transfer (CT) complexes were evaluated in this study. Experimental and theoretical approaches, including density function theory (DFT), were used to obtain the comprehensive, reliable, and accurate structure elucidation of the developed CT complexes. The CT complexes (KT-DDQ and KT-TCNQ) were monitored at 485 and 843 nm, respectively, and the calibration curve ranged from 10 to 100 ppm for KT-DDQ and 2.5 to 40 ppm for KT-TCNQ. The spectrophotometric methods were validated for the determination of KT, and the stability of the CT complexes was assessed by studying the corresponding spectroscopic physical parameters. The molar ratio of KT:DDQ and KT:TCNQ was estimated at 1:1 using Job’s method, which was compatible with the results obtained using the Benesi–Hildebrand equation. Using these complexes, the quantitative determination of KT in its dosage form was successful.

scholarly journals Spectrophotometric determination of quetiapine fumarate in pharmaceuticals and human urine by two charge-transfer complexation reactions

2012 ◽  
Vol 18 (2) ◽  
pp. 263-272 ◽  
Author(s):  
K.B. Vinay ◽  
H.D. Revenasiddappa
Keyword(s):  
Charge Transfer ◽  
Human Urine ◽  
Charge Transfer Complexes ◽  
Experimental Conditions ◽  
Chloranilic Acid ◽  
Quetiapine Fumarate ◽  
Complexation Reactions ◽  
Charge Transfer Complexation ◽  
Spiked Human Urine

Two simple, rapid and accurate spectrophotometric procedures are proposed for the determination of quetiapine fumarate (QTF) in pharmaceuticals and in spiked human urine. The methods are based on charge transfer complexation reactions of free base form of the drug (quetiapine, QTP), as n-electron donor (D), with either p-chloranilic acid (p-CAA) (method A) or 2,3-dichloro-5,6-dicyanoquinone (DDQ) (method B) as ?-acceptors (A). The coloured charge transfer complexes produced exhibit absorption maxima at 520 and 540 nm, in method A and method B, respectively. The experimental conditions such as reagent concentration, reaction solvent and time have been carefully optimized to achieve the maximum sensitivity. Beer?s law is obeyed over the concentration ranges of 8.0 - 160 and 4.0 - 80.0 ?g ml-1, for method A and method B, respectively. The calculated molar absorptivity values are 1.77 ? 103 and 4.59 ? 103 l mol-1cm-1, respectively, for method A and method B. The Sandell sensitivity values, limits of detection (LOD) and quantification (LOQ) have also been reported. The stoichiometry of the reaction in both cases was accomplished adopting the limiting logarithmic method and was found to be 1: 2 (D: A). 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 QTF in pharmaceutical formulations and spiked human urine.

scholarly journals Performance Characteristics of UV and Visible Spectrophotometry Methods for Quantitative Determination of Norfloxacin in Tablets

2014 ◽  
Vol 6 (3) ◽  
pp. 531-541 ◽  
Author(s):  
L. Chierentin ◽  
H. R. N. Salgado
Keyword(s):  
Absorption Maximum ◽  
Good Accuracy ◽  
Chloranilic Acid ◽  
Spectrophotometric Methods ◽  
Ich Guidelines ◽  
Label Claim ◽  
Acid Reagent ◽  
Development And Validation ◽  
Good Agreement

This work has proposed the development and validation of ultraviolet (UV) and visible (Vis) spectrophotometric methods for the determination of norfloxacin in the tablets. The proposed methods were applied to pharmaceutical formulation and percent amount of drug estimated (96.08% for UV method and 102.65% for Vis method) and was found in good agreement with the label claim. Using the UV method norfloxacin showed an absorption maximum at 277 nm, in 0.1 M hydrochloridric acid medium, whereas for the Vis spectrophotometric method it reacts with chloranilic acid reagent, forming a purple solution with an absorption maximum at 520 nm. The calibrations curves were linear over the working range of 2.0-7.0 ?g.mL-1 for the UV method and 90.0-120.0 ?g/mL for the Vis method. The linear regression equation for UV method was y = 0.1303x+0.0026 (r2=0.9999) and for Vis method y = 0.0037x-0.0069 (r2 = 0.9948), they proved to be linear. The methods were completely validated according to the International Conference Harmonization (ICH) guidelines, showing good accuracy, precision, selectivity, linearity and robustness. Therefore the both methods were found to be simple, rapid, sensitive, and easily contributing to the quality control of norfloxacin tablets while being interchangeable. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i3.18381 J. Sci. Res. 6 (3), 531-541 (2014)

scholarly journals Simple Methods for the Spectrophotometric Determination of Carvedilol

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Divya N. Shetty ◽  
B. Narayana
Keyword(s):  
Charge Transfer ◽  
Complex Formation ◽  
Confidence Level ◽  
Charge Transfer Complex ◽  
Condensation Reaction ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision

Two simple spectrophotometric methods are described for the determination of carvedilol (CAR). Method A is the condensation reaction of CAR with p-dimethylaminobenzaldehyde (PDAB), and the reaction mixture exhibits maximum absorbance at 601 nm. Method B is based on the charge transfer complex formation of CAR with p-chloranil; the color developed is measured at 662 nm. The calibration graphs are found to be linear over 50.00–250.00 and 20.00–100.0 μg mL−1 with molar absorptivity values of 0.92×103 and 0.257×104 L mol−1cm−1 for CAR-PDAB and CAR-p-chloranil, respectively. Statistical comparisons of the results are performed with regard to accuracy and precision using Student’s t-test and F-test at 95% confidence level. The methods are successfully employed for the determination of CAR in pharmaceutical preparations, and the results agree favorably with the reference and proposed methods.

scholarly journals Application of two charge transfer complex formation reactions for selective determination of metformin hydrochloride in pharmaceuticals and urine

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Nagaraju Rajendraprasad ◽  
Kanakapura Basavaiah
Keyword(s):  
Charge Transfer ◽  
Bulk Sample ◽  
Molar Absorptivity ◽  
Metformin Hydrochloride ◽  
Complexing Agents ◽  
Chloranilic Acid ◽  
Selective Determination ◽  
Spectrophotometric Methods ◽  
Relative Errors ◽  
Replicate Measurements

Abstract Background Metformin hydrochloride (MFH) is a biguanide class anti-diabetic drug used to treat type-2 diabetes mellitus. Its reaction with two charge-transfer complexing agents, p-chloranilic acid (PCA) and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in acetonitrile medium to yield coloured products measurable at wavelengths of maxima 530.0 and 460.0 nm, respectively, was conveniently used to develop two spectrophotometric methods for analyses of bulk sample and tablets. Results The effect of solvent, reagent concentration and reaction time to form charge-transfer (CT) complexes was meticulously studied and optimized. Under optimised conditions, the absorbance at the respective wavelength of maximum versus concentration of MFH was in linear correlation for the range from 8.0 to 320.0 and from 1.6 to 64.0 μg mL-1 in PCA and DDQ methods, respectively, and correspondingly, the values of molar absorptivity of 0.733 × 103 and 0.257 × 104 L mol-1 cm-1 and Sandell sensitivity of 0.3620 and 0.0644 μg cm-2. The quantification (QL) and detection (DL) limits were 2.67 and 0.88 μg mL-1 for PCA method, and 0.33 and 0.11 μg mL-1 for DDQ method. Conclusion The new methods were emerged as repeatable and reproducible, with replicate measurements for intra- and inter-day variations as showed by obtained RSD values of < 2%. Within a day and between day relative errors were ≤ 2.18%. Methods were also validated for robustness, ruggedness and selectivity and agreeing results were produced. The methods were used to analyse MFH-containing tablets very accurately and precisely as reflected by the mean recovery value close to 100% and lower RSD values, respectively. Analysis of spiked human urine yielded excellent mean recoveries, indicating the absence of interference from endogenous substances.

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