Spectrophotometric study on the charge transfer complex between sumatriptan succinate and some π-acceptors and alizarin derivatives

A facile, accurate, sensitive and validated spectrophotometric methods for the determination of sumatriptan succinate (SMT) in pure and in dosage forms are described. The methods are based on the formation of charge transfer products between SMT and chromogenic reagents 2,3-dichloro-5,6 dicyano-p-benzoquinone (DDQ), 7,7,8,8-tetracyanoquinodimethane(TCNQ), quinalizarin (Quiz) and alizarin red S (ARS) producing charge transfer complexes which showed an absorption maximum at 461, 841, 567 and 529 nm for DDQ, TCNQ, Quiz and ARS, respectively. The optimization of the reaction conditions such as the type of solvent, reagent concentration and reaction time were investigated. Beer?s law is obeyed in the concentration ranges 1.0-80 mg mL-1. The molar absorptivity, Sandell sensitivity, detection and quantification limits are also calculated. The correlation coefficient was ?0.9994 with a relative standard deviation (R.S.D.) of ? 1.08. The proposed methods were successfully applied for determination of sumatriptan in tablets with good accuracy and precision and without interferences from common additives by applying the standard addition technique. Developed methods have been validated statistically for their accuracy, precision, sensitivity, selectivity, robustness and ruggedness as per ICH guidelines and the results compared favourably with those obtained using the reported method.

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Utility of Charge Transfer and Ion-Pair Complexation for Spectrophotometric Determination of Eletriptan Hydrobromide in Pure and Dosage Forms

Journal of Chemistry ◽

10.1155/2013/402164 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Ayman A. Gouda ◽

Ragaa El Sheikh ◽

Rham M. El-Azzazy

Keyword(s):

Charge Transfer ◽

Correlation Coefficients ◽

Standard Addition ◽

Molar Absorptivity ◽

Dosage Forms ◽

Ion Pair ◽

Charge Transfer Complexes ◽

Alizarin Red ◽

Relative Standard

Three simple, sensitive, and accurate spectrophotometric methods have been developed for the determination of eletriptan hydrobromide (ELT) in pure and dosage forms. The first two methods are based on charge transfer complex formation between ELT and chromogenic reagents quinalizarin (Quinz) and alizarin red S (ARS) producing charge transfer complexes which showed an absorption maximum at 569 and 533 nm for Quinz and ARS, respectively. The third method is based on the formation of ion-pair complex between ELT with molybdenum(V)-thiocyanate inorganic complex in hydrochloric acid medium followed by extraction of the colored ion-pair with dichloromethane and measured at 470 nm. Different variables affecting the reactions were studied and optimized. Beer's law is obeyed in the concentration ranges 2.0–18, 1.0–8.0, and 2.0–32 μg mL−1for Quinz, ARS, and Mo(V)-thiocyanate, respectively. The molar absorptivity, Sandell sensitivity, detection, and quantification limits are also calculated. The correlation coefficients were ≥0.9994 with a relative standard deviation (R.S.D%.) of ≤0.925. The proposed methods were successfully applied for simultaneous determination of ELT in tablets with good accuracy and precision and without interferences from common additives, and the validity is assessed by applying the standard addition technique, which is compared with those obtained using the reported method.

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Validated Spectrophotometric Determination of Rizatriptan Benzoate in Pharmaceutical Formulations using Alizarin Derivatives

International Journal of Pharmaceutical Quality Assurance ◽

10.25258/ijpqa.10.1.2 ◽

2019 ◽

Vol 10 (01) ◽

Author(s):

El Sheikh R ◽

Hassan W. S. ◽

Gouda A. A. ◽

Al OwairdhiA. ◽

Al Hassani K K H

Keyword(s):

Standard Addition ◽

Pharmaceutical Formulations ◽

Molar Absorptivity ◽

Optimum Conditions ◽

Reaction Conditions ◽

Alizarin Red ◽

Rizatriptan Benzoate ◽

Spectrophotometric Methods ◽

Relative Standard

Two simple, sensitive, accurate, precise and economical spectrophotometric methods have been developed and validated for the determination of rizatriptan benzoate (RZT) in pure form and pharmaceutical formulations. These methods were based on the formation of charge transfer complex between RZT as n-electron donor and alizarin red S (ARS) or quinalizarin (Quinz) as π-acceptor in methanol to form highly colored chromogens which showed an absorption maximum at 532 and 574 nm using ARS and Quinz, respectively. The optimization of the reaction conditions such as the type of solvent, reagent concentration and reaction time were investigated. Under the optimum conditions, Beer’s law is obeyed in the concentration ranges 1.0-16 and 2.0-20 g mL-1 using ARS and Quinz, respectively with good correlation coefficient (r2 ≥ 0.9996) and with a relative standard deviation (RSD% ≤ 1.16). The molar absorptivity, Sandell sensitivity, detection and quantification limits were also calculated. The methods were successfully applied to the determination of RZT in its pharmaceutical formulations and the validity assesses by applying the standard addition technique. Results obtained by the proposed methods for the pure RZT and commercial tablets agreed well with those obtained by the reported method.

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SPECTROPHOTOMETRIC METHODS FOR DETERMINATION OF SOFOSBUVIR AND DACLATASVIR IN PURE AND DOSAGE FORMS

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2021v13i6.42564 ◽

2021 ◽

pp. 112-119

Author(s):

MONIR Z. SAAD ◽

ATEF AMER ◽

KHALED ELGENDY ◽

BASEM ELGENDY

Keyword(s):

Indigo Carmine ◽

Reference Method ◽

Standard Addition ◽

Pharmaceutical Formulations ◽

Molar Absorptivity ◽

Experimental Conditions ◽

Fixed Amount ◽

Alizarin Red ◽

Spectrophotometric Methods

Objective: Two simple, sensitive and accurate spectrophotometric methods have been developed for the determination of sofosbuvir (SOF) and daclatasvir (DAC) in pure forms and pharmaceutical formulations. Methods: The proposed methods are based on the oxidation of SOF and DAC by a known excess of cerium(IV) ammonium nitrate in sulphuric acid medium followed by determination of unreacted cerium(IV) by adding a fixed amount of indigo carmine (IC) and alizarin red S (ARS) dyes followed by measuring the absorbance at 610 and 360 nm, respectively. The experimental conditions affecting the reaction were studied and optimized. Results: The beer’s law was obeyed in the concentration ranges of 0.2-3.0, 0.2-4.0 for SOF and 0.5-4.5 and 0.5-5.0 μg/ml for DAC using IC and ARS methods, respectively with a correlation coefficient ≥ 0.9991. The calculated molar absorptivity values are 2.354 × 104, 1.933 × 104 for SOF and 1.786 × 104 and 2.015 × 104 L/mol. cm for DAC using IC and ARS methods, respectively u. The limits of detection and quantification are also reported. Intra-day and inter-day precision and accuracy of the methods have been evaluated. Conclusion: The methods were successfully applied to the assay of SOF and DAC in tablets and the results were statistically compared with those of the reference method by applying Student’s t-test and F-test. No interference was observed from the common tablet excipients. The accuracy and reliability of the methods were further ascertained by performing recovery studies using the standard addition method.

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

Journal of Analytical Methods in Chemistry ◽

10.1155/2012/875942 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 6

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.

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

Journal of Pharmaceutics ◽

10.1155/2013/792186 ◽

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 %).

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Use of Alizarin Red S as an Ion-Pair Reagent for the Spectrophotometric Assay of Fexofenadine in Pharmaceuticals and in Spiked Human Urine

ISRN Spectroscopy ◽

10.5402/2012/648510 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10

Author(s):

Madihalli S. Raghu ◽

Kanakapura Basavaiah ◽

Kudige N. Prashanth ◽

Kankapura B. Vinay

Keyword(s):

Human Urine ◽

Standard Addition ◽

Cost Effective ◽

Molar Absorptivity ◽

Ion Pair ◽

Alizarin Red S ◽

Alizarin Red ◽

Spectrophotometric Methods ◽

Spiked Human Urine

The present study describes two simple, rapid, selective, and cost-effective spectrophotometric methods for the determination of an antiallergic drug, fexofenadine hydrochloride (FFH), in bulk drug, tablets, and in spiked human urine. The first method (method A) is based on the formation of yellow-colored ion-pair complex between FFH and alizarin red S (AZS) in acid medium which was extracted into dichloromethane, and the absorbance was measured at 440 nm. The second method (method B) is based on the breaking of the yellow FFH–AZS ion-pair complex in alkaline medium followed by the measurement of the violet-colored free dye at 590 nm. Under the optimized conditions, Beer’s law is obeyed over the concentration ranges of 0.4–12.0 and 0.2–3.5 μg FFH for method A and method B, respectively, and the corresponding molar absorptivity values are 3.80 × 104 and 1.61 × 105 L . The Sandell’s sensitivity, detection, and quantification limits are also reported. The proposed methods were successfully applied to the determination of FFH in pure drug and commercial tablets. The accuracy and reliability of the proposed methods were further established by recovery studies via standard addition technique.

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

Molecules ◽

10.3390/molecules26072039 ◽

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.

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Cerimetric determination of simvastatin in pharmaceuticals based on redox and complex formation reactions

Eclética Química Journal ◽

10.26850/1678-4618eqj.v33.2.2008.p21-28 ◽

2018 ◽

Vol 33 (2) ◽

pp. 21

Author(s):

Kanakapura Basavaiah ◽

Okram Zenita Devi

Keyword(s):

Limit Of Detection ◽

Reference Method ◽

Standard Addition ◽

Molar Absorptivity ◽

Experimental Conditions ◽

Spectrophotometric Methods ◽

Fixed Quantity ◽

Bulk Drug ◽

Student’S T

Two sensitive spectrophotometric methods are described for the determination of simvastatin (SMT) in bulk drug and in tablets. The methods are based on the oxidation of SMT by a measured excess of cerium (IV) in acid medium followed by determination of unreacted oxidant by two different reaction schemes. In one procedure (method A), the residual cerium (IV) is reacted with a fixed concentration of ferroin and the increase in absorbance is measured at 510 nm. The second approach (method B) involves thereduction of the unreacted cerium (IV) with a fixed quantity of iron (II), and the resulting iron (III) is complexed with thiocyanate and the absorbance measured at 470 nm. In both methods, the amount of cerium (IV) reacted corresponds to SMT concentration. The experimental conditions for both methods were optimized. In method A, the absorbance is found to increase linearly with SMT concentration (r = 0.9995) whereas in method B, the same decreased (r = -0.9943). The systems obey Beer’s law for 0.6-7.5 and 0.5-5.0 μg mL-1 for method A and method B, respectively. The calculated molar absorptivity values are 2.7 X 104 and 1.06 X 105 Lmol-1 cm-1, respectively; and the corresponding sandel sensitivity values are 0.0153 and 0.0039μg cm-2, respectively. The limit of detection (LOD) and quantification (LOQ) are reported for both methods. Intra-day and inter-day precision, and accuracy of the methods were established as per the current ICH guidelines. The methods were successfully applied to the determination of SMT in tablets and the results were statistically compared with those of the reference method by applying the Student’s t-test and F-test. No interference was observed from the common excipients added to tablets. The accuracy and validity of the methods were further ascertained by performing recovery experiments via standard addition procedure.

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Spectrophotometric Methods for the Assay of Pyrilamine Maleate Using Chromogenic Reagents

E-Journal of Chemistry ◽

10.1155/2010/941506 ◽

2010 ◽

Vol 7 (4) ◽

pp. 1507-1513 ◽

Cited By ~ 1

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.

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Simple Methods for the Spectrophotometric Determination of Carvedilol

ISRN Spectroscopy ◽

10.5402/2012/373215 ◽

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.

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