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

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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A sensitive spectrophotometric determination of tadalafil in pharmaceutical preparations and industrial wastewater samples

Baghdad Science Journal ◽

10.21123/bsj.10.3.1005-1013 ◽

2013 ◽

Vol 10 (3) ◽

pp. 1005-1013 ◽

Cited By ~ 2

Author(s):

Baghdad Science Journal

Keyword(s):

Standard Deviation ◽

Industrial Wastewater ◽

Pharmaceutical Preparations ◽

Pharmaceutical Formulations ◽

Molar Absorptivity ◽

Average Recovery ◽

Relative Standard ◽

Wastewater Samples ◽

Sensitive Spectrophotometric Method

A simple, accurate, precise, rapid, economical and a high sensitive spectrophotometric method has been developed for the determination of tadalafil in pharmaceutical preparations and industrial wastewater samples, which shows a maximum absorbance at 204 nm in 1:1 ethanol-water. Beer's law was obeyed in the range of 1-7?g/ mL ,with molar absorptivity and Sandell ? s sensitivity of 0.783x105l/mol.cm and 4.97 ng/cm2respectively, relative standard deviation of the method was less than 1.7%, and accuracy (average recovery %) was 100 ± 0. 13. The limits of detection and quantitation are 0.18 and 0.54 µg .ml-1, respectively. The method was successfully applied to the determination of tadalafil in some pharmaceutical formulations (tablets) and industrial wastewater samples. The proposed method was validated by sensitivity and precision which proves suitability for the routine analysis of tadalafil in true samples.

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

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq111006003v ◽

2012 ◽

Vol 18 (2) ◽

pp. 263-272 ◽

Cited By ~ 4

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.

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Spectrophotometric Assay of some Nitrogen Containing Drugs in Pharmaceutical Formulations using p-Chloranilic Acid Reagent

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v9i1.2299 ◽

2013 ◽

Vol 9 (1) ◽

pp. 1798-1809 ◽

Cited By ~ 2

Author(s):

Theia’a N. Al-Sabha ◽

Mahmood A. Hasan ◽

Huda A. Ibrahim

Keyword(s):

Pharmaceutical Formulations ◽

Molar Absorptivity ◽

Charge Transfer Complexes ◽

Amino Groups ◽

Chloranilic Acid ◽

Terbutaline Sulfate ◽

Acid Reagent ◽

Sulfacetamide Sodium ◽

Better Than

A spectrophotometric method is developed for the determination of some drugs containing amino groups (sulfacetamide sodium, lidocaine and terbutaline sulfate) based on their reaction with p-chloranilic acid reagent in an organic medium forming colored charge transfer complexes. The complexes have maximum absorptions at 530 and 527 nm for sulfacetamide sodium and lidocaine respectively, but terbutaline sulfate gave two maximum absorptions at 529 and 319 nm. Beers law is obeyed over the concentration range of 10-60 µg.ml-1 for sulfacetamide sodium and lidocaine and 5-70 µg.ml-1 for terbutaline sulfate. The molar absorptivity values are 0.940×103, 0.913×103 L.mol-1.cm-1 for sulfacetamide sodium and lidocaine respectively while terbutaline sulfate gave 0.987×103 L.mol-1.cm-1 at 529 nm and 7.407×103 L.mol-1.cm-1 at 319 nm with accuracy range between 100.20% and 101.42% and RSD better than 3.15% for all drugs. The method is applied successfully for determination of these drugs in pharmaceutical formulations and compared favorably with British Pharmacopeia standard methods. F and t tests are less than the tabulated values at 95% confidence level.

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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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Spectrophotometric Analysis of Selective Serotonin Reuptake Inhibitors Based on Formation of Charge-Transfer Complexes with Tetracyanoquinodimethane and Chloranilic Acid

Journal of AOAC International ◽

10.1093/jaoac/89.2.326 ◽

2006 ◽

Vol 89 (2) ◽

pp. 326-333 ◽

Cited By ~ 18

Author(s):

Ibrahim A Darwish ◽

Ibrahim H Refaat

Keyword(s):

Charge Transfer ◽

Serotonin Reuptake ◽

Selective Serotonin Reuptake Inhibitors ◽

Pharmaceutical Formulations ◽

Spectrophotometric Analysis ◽

Serotonin Reuptake Inhibitors ◽

Selective Serotonin ◽

Charge Transfer Complexes ◽

Chloranilic Acid ◽

Relative Standard

Abstract A simple, accurate, and sensitive spectrophotometric method for analysis of selective serotonin reuptake inhibitors (SSRIs) has been developed and validated. The analysis was based on the formation of colored charge-transfer complexes between the intact molecule of SSRI drug as an n-electron donor and each of tetracyanoquinodimethane (TCNQ) or p-chloranilic acid (pCA) as electron acceptors. The formed complexes were measured spectrophotometrically at 842 and 520 nm for TCNQ and pCA, respectively. Different variables and parameters affecting the reactions were studied and optimized. Under the optimum reaction conditions, linear relationships with good correlation coefficients (0.99750.9996) were found between the absorbances and the concentrations of the investigated drugs in the concentration ranges of 450 and 20400 g/mL with TCNQ and pCA, respectively. With all the investigated drugs, TCNQ gave more sensitive assays than pCA; the limits of assay detection were 2.54.8 and 2040 g/mLwith TCNQ and pCA, respectively. The intra- and interassay precisions were satisfactory; the relative standard deviations did not exceed 2. The proposed procedures were successfully applied to the analysis of the studied drugs in pure form and pharmaceutical formulations with good accuracy; the recovery values were 98.4102.8 1.241.81. The results obtained from the proposed method were statistically comparable with those obtained from the previously reported methods.

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

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq1205133087e ◽

2013 ◽

Vol 19 (4) ◽

pp. 529-540 ◽

Cited By ~ 2

Author(s):

Sheikh El ◽

Ayman Gouda ◽

Rham El-Azzazy

Keyword(s):

Charge Transfer ◽

Standard Addition ◽

Spectrophotometric Study ◽

Molar Absorptivity ◽

Charge Transfer Complexes ◽

Alizarin Red ◽

Spectrophotometric Methods ◽

Sumatriptan Succinate ◽

Relative Standard

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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Determination of Meropenem by Spectrophotometric-Application to Pharmaceutical Preparations

Tikrit Journal of Pure Science ◽

10.25130/j.v25i1.938 ◽

2020 ◽

Vol 25 (1) ◽

pp. 68

Author(s):

Nada A. Khalil ◽

Walada H. Ibrahim

Keyword(s):

Charge Transfer Complex ◽

Concentration Level ◽

Pharmaceutical Preparation ◽

Pharmaceutical Preparations ◽

Pharmaceutical Formulations ◽

Molar Absorptivity ◽

Sensitivity Index ◽

Relative Standard ◽

Better Than

A simple and sensitive spectrophotometric method was described for the determination of Meropenem in pure and in pharmaceutical formulations. 2,3 dichloro 5,6 dicyano 1,4 benzoquinone(DDQ)has been used for determination of meropenem by formation of charge transfer complex measured at 345 nm.Beer᾽s law is obeyed in the concentration range of (0.625-12.5µg/ml) The molar absorptivity (2.3889×104)l.mol1-.cm1-,Sandellʹs sensitivity index is 0.0161µg.cm2-,The method is precise (relative standard deviation RSD% is better than ±3.32%) and accurate (relative error in the range of -0.97 to-0.60%) depending on the concentration level. The method was applied succefully to the assay of Meropenem in pharmaceutical preparation in the form of injection. http://dx.doi.org/10.25130/tjps.25.2020.012

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Eco- Friendly Method for the Estimation of Warfarin Sodium in Pharmaceutical Preparations and Environmental Wastewater Samples

10.47363/jmhc/2021(3)155 ◽

2020 ◽

pp. 1-3

Author(s):

Nief Rahman Ahmed ◽

Keyword(s):

Industrial Wastewater ◽

Pharmaceutical Preparations ◽

Pharmaceutical Formulations ◽

Molar Absorptivity ◽

Distilled Water ◽

Average Recovery ◽

Warfarin Sodium ◽

Relative Standard ◽

Wastewater Samples

A simple, precise, accurate, rapid, economical and sensitive ultraviolet spectrophotometric method has been developed for the determination of warfarin sodium in pharmaceutical preparations and environmental wastewater samples, which shows maximum absorbance at 310 nm in distilled water. Beer’s law was obeyed in the range of 2-30μg/ ml ,with molar absorptivity of 1.1 ×104 L.mol-1.cm-1 , relative standard deviation of the method was less than 1.8%, and accuracy (average recovery %) was 100 ± 1.0 . The method was successfully applied to the determination of warfarin sodium in some pharmaceutical formulations (Tablets) and industrial wastewater samples. The proposed method was validated by sensitivity and precision which proves suitability for the routine analysis of warfarin sodium in true samples.

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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

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2019v11i4.32715 ◽

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.

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