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

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
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.

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

2013 ◽  
Vol 19 (4) ◽  
pp. 529-540 ◽  
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.

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 Spectrophotometric Determination of Zidovudine in Pharmaceuticals Based on Charge-Transfer Complexation Involving N-Bromosuccinimide, Metol and Sulphanilic Acid as Reagents

2007 ◽  
Vol 4 (2) ◽  
pp. 173-179 ◽  
Author(s):  
K. Basavaiah ◽  
U. R. Anil Kumar
Keyword(s):  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Sulphanilic Acid ◽  
Bulk Drug ◽  
Student’S T ◽  
Charge Transfer Complexation

A simple spectrophotometric method is proposed for the determination of zidovudine(ZDV) in bulk drug and in pharmaceutical preparations. The method is based on the oxidation of ZDV by a known excess of oxidant N-bromosuccinimide (NBS), in buffer medium of pH 1.5, followed by the estimation of unreacted amount of oxidant with metol and sulphanilic acid. The reacted oxidant corresponds to the amount ZDV. The purple-red reaction product absorbs maximally at 530 nm and Beer’s law is obeyed over a range 5 to 75 μg mL-1. The apparent molar absorptivity is calculated to be 5.1×103L mol-1cm-1, and the corresponding Sandell sensitivity value is 0.052 μg cm-2. The limit of detection and quantification are found to be 0.90 and 2.72, respectively. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The method was successfully applied to the assay of ZDV in tablet/capsule preparations 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 tablet/capsule excipients. The accuracy of the method was further ascertained by performing recovery studies via standard-addition method.

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

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.

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

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.

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

2013 ◽  
Vol 9 (1) ◽  
pp. 1798-1809 ◽  
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.

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).

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