scholarly journals Indirect spectrophotometric determination of diltiazem hydrochloride in pure form and pharmaceutical formulations

2005 ◽  
Vol 3 (3) ◽  
pp. 520-536 ◽  
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.

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

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.

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 Gemifloxacin Mesylate, Moxifloxacin Hydrochloride, and Enrofloxacin in Pharmaceutical Formulations Using Acid Dyes

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Ayman A. Gouda ◽  
Alaa S. Amin ◽  
Ragaa El-Sheikh ◽  
Amira G. Yousef
Keyword(s):  
Pharmaceutical Formulations ◽  
Bromothymol Blue ◽  
Bromocresol Green ◽  
Bromophenol Blue ◽  
Bromocresol Purple ◽  
Acid Dyes ◽  
Spectrophotometric Methods ◽  
Significant Difference ◽  
Comparison Of The Results

Simple, rapid, and extractive spectrophotometric methods were developed for the determination of some fluoroquinolones antibiotics: gemifloxacin mesylate (GMF), moxifloxacin hydrochloride (MXF), and enrofloxacin (ENF) in pure forms and pharmaceutical formulations. These methods are based on the formation of ion-pair complexes between the basic drugs and acid dyes, namely, bromocresol green (BCG), bromocresol purple (BCP), bromophenol blue (BPB), bromothymol blue (BTB), and methyl orange (MO) in acidic buffer solutions. The formed complexes were extracted with chloroform and measured at 420, 408, 416, 415, and 422 nm for BCG, BCP, BPB, BTB, and MO, respectively, for GMF; at 410, 415, 416, and 420 nm for BCP, BTB, BPB, and MO, respectively, for MXF; and at 419 and 414 nm for BCG and BTB, respectively, in case of ENF. The analytical parameters and their effects are investigated. Beer’s law was obeyed in the ranges 1.0–30, 1.0–20, and 2.0–24 μg mL−1for GMF, MXF, and ENF, respectively. The proposed methods have been applied successfully for the analysis of the studied drugs in pure forms and pharmaceutical formulations. Statistical comparison of the results with the reference methods showed excellent agreement and indicated no significant difference in accuracy and precision.

scholarly journals Spectrophotometric Determination of Pipazethate Hydrochloride in Pure Form and in Pharmaceutical Formulations

2007 ◽  
Vol 90 (3) ◽  
pp. 686-692 ◽  
Author(s):  
Ragaa El-Shiekh ◽  
Alaa S Amin ◽  
Faten Zahran ◽  
Ayman A Gouda
Keyword(s):  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Pure Form ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Accurate Analysis ◽  
Spectrophotometric Methods ◽  
Relative Standard ◽  
Optimum Ph

Abstract Three simple, sensitive, and reproducible spectrophotometric methods (AC) for the determination of pipazethate hydrochloride (PiCl) in pure form and in pharmaceutical formulations are described. The first and second methods, A and B, are based on the oxidation of the drug by Fe3+ in the presence of o-phenanthroline (o-phen) or bipyridyl (bipy). The formation of tris-complex upon reactions with Fe3+-o-phen and/or Fe3+-bipy mixture in an acetate buffer solution of the optimum pH values was demonstrated at 510 and 522 nm, respectively, with o-phen and bipy. The third method, C, is based on the reduction of Fe(III) by PiCl in acid medium and subsequent interaction of Fe(II) with ferricyanide to form Prussian blue, which exhibits an absorption maximum at 750 nm. The concentration ranges are from 0.5 to 8, 2 to 16, and 3 to 15 g/mL for Methods AC, respectively. For more accurate analysis, Ringbom optimum concentration ranges were calculated. The molar absorptivity, Sandell sensitivity, and detection and quantitation limits were calculated. The developed methods were successfully applied to the determination of PiCl in bulk and pharmaceutical formulations without any interference from common excipients. The relative standard deviations were 0.83% with recoveries of 98.9101.15%.

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

2012 ◽  
Vol 18 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Nagaraj Prashanth ◽  
Kanakapura Basavaiah ◽  
Sameer Abdulrahman ◽  
Nagaraju Rajendraprasad ◽  
Basavaiah Vinay
Keyword(s):  
Reference Method ◽  
Standard Addition ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Highly Sensitive ◽  
Bromination Reaction ◽  
Excess Iodide ◽  
Good Agreement

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.

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

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.

scholarly journals Sensitive and Selective Spectrophotometric Determination of Gabapentin in Capsules Using Two Nitrophenols as Chromogenic Agents

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Sameer A. M. Abdulrahman ◽  
Kanakapura Basavaiah
Keyword(s):  
Picric Acid ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Ion Pair ◽  
Lewis Base ◽  
Pure Form ◽  
Experimental Conditions ◽  
Spectrophotometric Methods ◽  
Significant Difference

Two simple and selective spectrophotometric methods have been proposed for the determination of gabapentin (GBP) in pure form and in capsules. Both methods are based on the proton transfer from the Lewis acid such as 2,4,6-trinitrophenol (picric acid; PA) or 2,4-dinitrophenol (2,4-DNP) to the primary amino group of GBP which works as Lewis base and formation of yellow ion-pair complexes. The ion-pair complexes formed show absorption maximum at 415 and 420 nm for PA and 2,4-DNP, respectively. Under the optimized experimental conditions, Beer's law is obeyed over the concentration ranges of 1.25–15.0 and 2.0–18.0 μg mL−1GBP for PA and 2,4-DNP methods, respectively. The molar absorptivity, Sandell's sensitivity, detection and, quantification limits for both methods are also reported. The proposed methods were applied successfully to the determination of GBP in pure form and commercial capsules. Statistical comparison of the results was performed using Student'st-test and F-ratio at 95% confidence level, and there was no significant difference between the reference and proposed methods with regard to accuracy and precision. Further, the validity of the proposed methods was confirmed by recovery studies via standard addition technique.

scholarly journals Quantitative analysis of perindopril erbumine in pharmaceutical preparations by spectrophotometry via ternary complex formation with Zn(II) and eosin and charge transfer complexation with iodine

2011 ◽  
Vol 25 (2) ◽  
pp. 123-136 ◽  
Author(s):  
Nafisur Rahman ◽  
Habibur Rahman
Keyword(s):  
Charge Transfer ◽  
Ternary Complex ◽  
Pharmaceutical Preparations ◽  
Reference Method ◽  
Molar Absorptivity ◽  
Experimental Conditions ◽  
Spectrophotometric Methods ◽  
Significant Difference ◽  
Comparison Of The Results ◽  
Charge Transfer Complexation

Two simple, sensitive and accurate spectrophotometric methods have been developed for the analysis of perindopril in pharmaceutical preparations. Method A is based on the formation of ternary complex between zinc(II), eosin and the perindopril, which is extractable with chloroform. The absorption spectrum exhibits a band peaking at 510 nm. Method B is based on the interaction of drug with iodine in dichloromethane resulting in the formation of charge transfer complex which absorbs maximally at 365 nm. Beer's law is obeyed in the concentration range 10–200 μg/ml and 10–180 μg/ml with molar absorptivity of 2.25×103and 3.71×103l/mol·cm for methods A and B, respectively. The detection limits for methods A and B are 0.49 and 0.90 μg/ml, respectively. The optimum experimental conditions for the proposed procedures are investigated. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference between the methods compared in terms of accuracy and precision.

scholarly journals Titrimetric and spectrophotometric assay of felodipine in tablets using bromate–bromide, Methyl Orange and Indigo Carmine reagents

2005 ◽  
Vol 70 (7) ◽  
pp. 969-978 ◽  
Author(s):  
Kanakapura Basavaiah ◽  
Umakanthappa Chandrashekar ◽  
Nage Gowda
Keyword(s):  
Methyl Orange ◽  
Indigo Carmine ◽  
Reference Method ◽  
Pharmaceutical Formulations ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Bulk Drug ◽  
Reaction Stoichiometry ◽  
Comparison Of The Results

Three new methods based on titrimetric and spectrophotometric techniques are described for the determination of felodipine (FLD) in the bulk drug and in tablets using a bromate?bromide mixture and two dyes, Methyl Orange and Indigo Carmine. In the titrimetric method (method A), the drug solution was treated with a measured excess of the bromate?bromide mixture in acid medium and after the reaction was judged to be complete, the unreacted bromine was determined iodometrically. The two spectrophotometric methods are based on the bromination of the drug with a known excess of the bromate?bromide mixture under acidic conditions followed by the estimation of the surplus bromine by reaction with either Methyl Orange (Method B) or Indigo Carmine (Method C) and measuring the absorbance at 520 nm or 610 nm, respectively. In all the methods, the amount of reacted bromine corresponds to the drug content. The titrimetric procedure is applicable for between 6?15 mg and the reaction stoichiometry was found to be 1:1 (drug: BrO3?). The systems obey Beer?s law between 0.12 ? 0.87 ?gml-1 and 0.5 ? 6.0 ?gml-1 formethods B and C respectively. The limits of detection and quantification are reported for both the spectrophotometric methods. The methods could usefully be applied to routine quality control of pharmaceutical formulations containing FLD. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

scholarly journals Spectrophotometric Determination of Carbamazepine in Pharmaceutical Formulations Based on its Reaction with a Brominating Agent

2019 ◽  
Vol 9 (2) ◽  
pp. 42-49
Author(s):  
Warda Rizgar ◽  
Diyar S. Ali
Keyword(s):  
Methylene Blue ◽  
Spectrophotometric Determination ◽  
General Procedure ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Pure Form ◽  
Great Precision ◽  
Spectrophotometric Methods ◽  
Precision And Accuracy

Two accurate spectrophotometric methods described for the estimation of carbamazepine (CBZ) in both pharmaceutical and pure form. These methodologies are attached to the bromination of CBZ by bromine formed in instantly from the bromate-bromide reaction. The general procedure includes the additional of a known amount of bromate-bromide reagent in an acidic mediocre to CBZ. After the reaction is integrated, the unreacted bromine was reacted with a steady amount of methylene blue, and the absorbance was measured at 665 nm (method A) or, cresol red could be used for the reaction and the absorbance moderated at 517 nm (method B). Beer’s law was submitted from 0.45 to 15.00 μg/mL CBZ with a molar absorptivity of 4.93 × 103 L/mol.cm for method A and from 0.50 to 12.00 μg/mL CBZ with a molar absorptivity of 1.37 × 104 L/mol.cm for method B. The proposed methods were effective for the determination of CBZ in tablets with great precision and accuracy.

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