Application of bromate-bromide mixture as a green brominating agent for the spectrophotometric determination of atenolol in pharmaceuticals

Two highly sensitive spectrophotometric methods are proposed for the quantification of atenolol (ATN) in pure drug as well as in pharmaceutical formulations. The methods are based on the bromination reaction of ATN with a known excess of bromate-bromide mixture in acid medium followed by the determination of unreacted bromine. The residual bromine is determined by its reaction with excess iodide and the liberated iodine (I3?) is either measured at 360 nm (method A) or reacted with starch followed by the measurement of the starch-iodine chromogen at 570 nm (method B). Under the optimum conditions, ATN could be assayed in the concentration ranges of 0.5-9.0 and 0.3-6.0?g mL-1 for method A and method B, respectively, with corresponding molar absorptivity values of 2.36?104 and 2.89?104 L/mol.cm. Sandell?s sensitivity values are found to be 0.0113 and 0.0092 ?g/cm2 for method A and method B, respectively. The proposed methods were successfully applied to the analysis of different commercial brands of pharmaceutical formulations and the results obtained by the proposed methods were in good agreement with those obtained using the reference method. The reliability of the methods was further ascertained by recovery studies using standard- addition 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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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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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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Indirect spectrophotometric determination of diltiazem hydrochloride in pure form and pharmaceutical formulations

Open Chemistry ◽

10.2478/bf02479280 ◽

2005 ◽

Vol 3 (3) ◽

pp. 520-536 ◽

Cited By ~ 2

Author(s):

Akram El-Didamony

Keyword(s):

Reference Method ◽

Pharmaceutical Formulations ◽

Molar Absorptivity ◽

Pure Form ◽

Diltiazem Hydrochloride ◽

Spectrophotometric Methods ◽

Chromotrope 2R ◽

Significant Difference ◽

Comparison Of The Results

AbstractThree simple, accurate, and sensitive spectrophotometric methods (A, B and C) have been described for the indirect assay of diltiazem hydrochloride (DIL.HCl), either in pure form or in pharmaceutical formulations. The first method (A) is based on the oxidation of DIL.HCl by N-bromosuccinimide (NBS) and determination of unconsumed NBS by measuring the decrease in absorbance of amaranth dye (AM) at a suitable λmax=521 nm. Other methods (B) and (C) involve the addition of excess cerric ammonium sulfate (CAS) and subsequent determination of the unconsumed oxidant by a decrease in the red color of chromotrope 2R (C2R) at a suitable λmax=528 nm or a decrease in the orange-pink color of rhodamine 6G (Rh6G) at λmax=525 nm, respectively. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges 3.0–9.0, 3.5–7.0 and 3.5–6.3 μg ml−1 for methods A, B and C, respectively. The apparent molar absorptivity, Sandell's sensitivity, detection and quantification limits were calculated. The proposed methods have been applied successfully for the analysis of the drug in its pure form and its dosage form. No interference was observed from a common pharmaceutical adjuvant. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

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Condensation Methods for the Determination of Darunavir in Pure and Pharmaceutical Formulations

International Journal of ChemTech Research ◽

10.20902/ijctr.2019.130408 ◽

2020 ◽

Vol 13 (4) ◽

pp. 394-401

Author(s):

M.L.N. Acharyulu ◽

P.V.S.R. Mohana Rao ◽

I. Siva Ramakoti

Keyword(s):

Regression Analysis ◽

Acidic Medium ◽

Low Cost ◽

Condensation Reaction ◽

Reference Method ◽

Pharmaceutical Formulations ◽

Molar Absorptivity ◽

Spectrophotometric Methods

Two visible spectrophotometric methods were developed Aand B for the determination of Darunavir in pure and pharmaceutical formulations. The methods are based on condensation reaction with PDAB (Method-A) and ONB (Method-B) in presence of acidic medium with the primaryamine group in DNV. The coloured products exhibit absorption λmax at 639 nm and 452nm for methods A and B respectively. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges 10-60μg/ml, 50-300 μg/ml, correlation co-efficients are 0.9983, 0.9989;Sandell’s sensitivities are9.9833 x 10-3, 3.0456 x 10-2(1 mole cm-1); and molar absorptivity values are5.4857 x 104,1.7981x 104 (μg cm-2) for methods-Aand B respectively. The proposed methods are applied to commercial available formulations and the results are statistically compared with those obtained by the UV reference method and validated by recovery studies. The results are found satisfactory and reproducible. These methods are applied successfully for the estimation of the DNV in the presence of other ingredients that are usually present in formulations. These methods offer the advantages of rapidity, simplicity and sensitivity and low cost without the need for expensive instrumentation and reagents.

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Simple and Selective Titrimetric and Spectrophotometric Methods for the Determination of Loratadine Using Bromate-Bromide, Methyl Orange and Methylene Blue

International Journal of Pharmaceutical Quality Assurance ◽

10.25258/ijpqa.v9i2.13636 ◽

2018 ◽

Vol 9 (2) ◽

Author(s):

Venkatachalam K ◽

Niranjani S ◽

Raju T

Keyword(s):

Methylene Blue ◽

Methyl Orange ◽

Reference Method ◽

Standard Addition ◽

Molar Absorptivity ◽

Stoichiometric Ratio ◽

Fixed Amount ◽

Spectrophotometric Methods ◽

Student’S T

One indirect titrimetric and two indirect visible spectrophotometric methods were described for the determination of loratadine in bulk drug and in its formulations. The methods used bromate-bromide, methyl orange and methylene blue as reagents. In titrimetry (method A), loratadine was treated with a known excess of bromate-bromide mixture in acidic medium and the residual bromine was back titrated iodometrically after the reaction between loratadine and in situ bromine was ensured to be complete. In spectrophotometric methods, the excess of bromine was estimated by treating with a fixed amount of either methyl orange (method B) and measuring the absorbance at 520 nm or methylene blue (method C) and measuring the absorbance at 680 nm. In all the methods, the amount of reacted bromine corresponded to the loratadine content. Titrimetric method was applicable over 1-8 mg range and the calculations were based on a 1:0.666 (loratadine:bromate) stoichiometric ratio. In spectrophotometry, the calibration graphs were found to be linear over 150- 350 and 1.75-3.5 μg mL-1 for method B and method C, respectively, with corresponding molar absorptivity values of 9.15 × 102 and 1.10 × 105 L mol-1 cm-1. Accuracy and precision of the assays were determined by computing the intra-day and inter-day variations at three different levels of loratadine. The methods were successfully applied to the assay of loratadine in tablet preparations and the results were compared with those of a reference method by applying Student’s t and F-tests. No interference was observed from common pharmaceutical excipients. The reliability of the methods was further ascertained by performing recovery tests by standard addition method

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Development and Validation of Highly Sensitive Spectrophotometric Methods for Cefpirome Determination in Pharmaceutical Dosage Forms

Asian Journal of Chemistry ◽

10.14233/ajchem.2021.23287 ◽

2021 ◽

Vol 33 (9) ◽

pp. 2059-2064

Author(s):

Basavaraj Hiremath

Keyword(s):

Pharmaceutical Formulations ◽

Molar Absorptivity ◽

Neutral Medium ◽

Pharmaceutical Dosage Forms ◽

Spectrophotometric Methods ◽

Highly Sensitive ◽

Development And Validation ◽

Medium Method ◽

Maximum Absorption Wavelength

Quantitative spectrophotometric determination of cefpirome in pure and pharmaceutical dosage has been developed. Method I produces a pink-coloured chromogen peak at λmax 510 nm by reacting diazotized cefpirome drugs with diphenylamine (DPA) in a neutral medium. Method II obtained of a coloured Schiff bases when cefpirome reacts with alcoholic p-dimethylaminobenzaldehyde (PDAB) to produce a yellow-coloured chromogen with a maximum absorption wavelength of 415 nm. In both methods I and II, Beer’s law is followed in the concentration ranges of 0.3-3.0 and 0.5-5.0 μg/mL, respectively, with molar absorptivity of 5.13 × 104 and 2.54 × 104 for each form. At three separate concentrations, intra-day and inter-day (RSD) and relative error (RE) are measured. The current methods are simple, reliable, inexpensive, speedy and highly reproducible and have been tested in broad range of pharmaceutical formulations with statistical comparisons to reference methods.

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Titrimetric and Spectrophotometric Assay of Oxcarbazepine in Pharmaceuticals Using N-Bromosuccinimide and Bromopyrogallol Red

International Journal of Analytical Chemistry ◽

10.1155/2011/138628 ◽

2011 ◽

Vol 2011 ◽

pp. 1-8

Author(s):

Nagaraju Rajendraprasad ◽

Kanakapura Basavaiah ◽

Kanakapura B. Vinay

Keyword(s):

Spectrophotometric Method ◽

Reference Method ◽

Standard Addition ◽

Molar Absorptivity ◽

Spectrophotometric Methods ◽

Bromopyrogallol Red ◽

Accuracy And Precision ◽

Significant Difference ◽

Comparison Of The Results

Titrimetric and spectrophotometric methods are described for the determination of oxcarbazepine (OXC) in bulk drug and in tablets. The methods use N-bromosuccinimide (NBS) and bromopyrogallol red (BPR) as reagents. In titrimetry (method A), an acidified solution of OXC is titrated directly with NBS using methyl orange as indicator. Spectrophotometry (method B) involves the addition of known excess of NBS to an acidified solution of OXC followed by the determination of the unreacted NBS by reacting with BPR and measuring the absorbance of the unreacted dye at 460 nm. Titrimetry allows the determination of 6–18 mg of OXC and follows a reaction stoichiometry of 1 : 1 (OXC : NBS), whereas spectrophotometry is applicable over the concentration range of 0.8–8.0 μg mL-1. Method B with a calculated molar absorptivity of2.52×104 L mol-1 cm-1is the most sensitive spectrophotometric method ever developed for OXC. The optical characteristics such as limits of detection (LOD), quantification (LOQ), and Sandell's sensitivity values are also reported for the spectrophotometric method. The accuracy and precision of the methods were studied on intraday and interday basis. The methods described could usefully be applied to routine quality control of tablets containing OXC. No interference was observed from common pharmaceutical adjuvants. Statistical comparison of the results with a reference method shows an excellent agreement and indicates no significant difference in accuracy and precision. The reliability of the methods was further ascertained by recovery studies in standard addition procedure.

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

E-Journal of Chemistry ◽

10.1155/2007/808130 ◽

2007 ◽

Vol 4 (2) ◽

pp. 173-179 ◽

Cited By ~ 3

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.

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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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