scholarly journals Nitroso-R-salt as a sensitive spectrophotometric reagent for the determination of paracetamol in pharmaceutical preparations

2009 ◽  
Vol 6 (3) ◽  
pp. 570-577
Author(s):  
Baghdad Science Journal
Keyword(s):  
Aqueous Solution ◽  
Statistical Difference ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Calibration Graph ◽  
Subsequent Reaction ◽  
Experimental Conditions ◽  
Colored Complex ◽  
British Pharmacopoeia

Nitroso-R-salt is proposed as a sensitive spectrophotometric reagent for the determination of paracetamol in aqueous solution. The method is based on the reaction of paracetamol with iron(III) and subsequent reaction with nitroso-R-salt to yield a green colored complex with maximum absorption at 720 nm. Optimization of the experimental conditions was described. The calibration graph was linear in the concentration range of 0.1 – 2.0 ?g mL-1 paracetamol with a molar absorptivity of 6.9 × 104 L mol-1 cm-1. The method was successfully applied to the determination of paracetamol in pharmaceutical preparations without any interference from common excipients. The method has been statistically evaluated with British Pharmacopoeia method and no statistical difference between methods was found at the 95% confidence level.

A Rapid and Accurate Non Extractive Procedure For Analyzing Monocrotophos In Environmental Samples By Spectrophotometry

2021 ◽  
Vol 30 (1) ◽  
pp. 66-73
Author(s):  
Kalpana Wani ◽  
Prashant Mundeja ◽  
Mamta Nirmal ◽  
Vindhiya Patel ◽  
Raisa Khatoon ◽  
...  
Keyword(s):  
Reaction System ◽  
Molar Absorptivity ◽  
Calibration Graph ◽  
Water Soluble ◽  
Experimental Conditions ◽  
Colored Complex ◽  
Bromination Reaction ◽  
Leuco Malachite Green ◽  
Effective Reaction

An organophosphorous insecticide monocrotophos is increasingly being utilized in agriculture to control insects on a broad range of crops. In this study a new reaction system using spectrophotometric method for quantitative determination of monocrotophos is proposed. The method is based on the bromination of monocrotophos to form dibromomonocrotophos which react with Potassium iodide-Potassium iodate mixture in the presence of leuco malachite green (LMG) to form a water soluble greenish blue colored complex. The change in absorbance as a criterion of the bromination reaction progress was followed spectrophotometrically. To obtain t he maximum sensitivity the effective reaction variables were optimized. The absorbance maximum was observed at 620 nm. Under optimized experimental conditions calibration graph was linear over the range of 10.0-60.0 µg. The molar absorptivity of the colored system is 3.66×104 L mol-1 cm-1 and sandell’s sensitivity is 0.25×10-2 µg cm-2. The calculated detection limit was 0.44 µg mL-1. The interfering effect of various species was also investigated. The present method was successfully applied to the analysis of monocrotophos in different environmental and water samples.

scholarly journals Development of a new analytical spectroscopic methodology based on the competitive aggregation in a dye–surfactant–drug system: Application to the determination of gemfibrozil

2008 ◽  
Vol 22 (4) ◽  
pp. 309-317 ◽  
Author(s):  
Mohammad Amjadi ◽  
Jamshid L. Manzoori ◽  
Leila Farzampour
Keyword(s):  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Calibration Graph ◽  
Experimental Conditions ◽  
Analytical Methodology ◽  
Surfactant Aggregates ◽  
Didodecyldimethylammonium Bromide ◽  
The Difference ◽  
Absorption Features

A new analytical methodology based on the competitive aggregation in a dye–surfactant–drug system is developed for the determination of gemfibrozil. Eriochrome Blue Black R (EBBR) and Didodecyldimethylammonium bromide (DDABr) were the dye and surfactant used, respectively. In the proposed method, the anions of the dye bind to the cationic surfactant molecules to form dye–surfactant aggregates, which are monitored from changes in UV-Vis absorption features of the dye. In the ternary EBBR–DDABr–drug mixtures, the drug competes with the dye to interact with the surfactant, which results in a decrease in dye–surfactant aggregates formation. This, again, causes a change in absorption properties of the dye. The measurement parameter is the difference between the absorption of the dye in the presence and absence of the drug. In the appropriate experimental conditions the absorbance differences are directly proportional to the drug concentration. The influence of several experimental variables such as pH, concentrations of buffer, EBBR and DDABr on the measurement parameter were studied. Under the optimum conditions, the calibration graph was linear up to 6.0 μg ml−1with the correlation coefficient of 0.998. The limit of detection and quantification were found to be 0.044 and 0.15 μg ml−1, respectively. The method was validated and applied to the determination of gemfibrozil in pharmaceutical preparations.

scholarly journals Spectrscopic and Conductometric Analysis of Gabapentin

2011 ◽  
Vol 8 (4) ◽  
pp. 1784-1796 ◽  
Author(s):  
Sara M. Anis ◽  
Mervat M. Hosny ◽  
Hisham E. Abdellatef ◽  
Mohamed N. El-Balkiny
Keyword(s):  
Methylene Chloride ◽  
Pharmaceutical Preparations ◽  
Bromothymol Blue ◽  
Molar Absorptivity ◽  
Cupric Chloride ◽  
Bromocresol Green ◽  
Stable Complex ◽  
Official Method ◽  
Experimental Conditions

Four simple, sensitive and reproducible methods were developed for the determination of gabapentin (GPT) in pure form and in pharmaceutical preparations. Methods A and B are based on the reaction of cupric chloride with gabapentin to form stable complex, which could be measured spectrophotometrically at λmax246 nm (method A) or by using conductometric technique (method B). While method C and D depends on the formation of ion pair complex between the studied drug and bromothymol blue, bromocresol green respectively this was extractable with methylene chloride. The concentration ranges were 40-95 μg mL-1, 1-15 mg, 100-800 and 10-150 μg mL-1for methods A, B, C and D respectively .The optimization of various experimental conditions were described .The results obtained showed good recoveries, Ringbom optimum concentration ranges were calculated, in addition to molar absorptivity and sandell’s sensitivity, detection and quantification limits. The methods were successfully applied to the determination of GPT in bulk and pharmaceutical preparations. The results were favorably comparable with the official method. The molar combining ratio for methods (A-B) was found to be (2:1) (drug: reagent) while for method (C-D) it was found to be (1:1).

scholarly journals Sensitive and selective spectrophotometric determination of pantoprazole sodium in pharmaceuticals using permanganate

2010 ◽  
Vol 16 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Zenita Devi ◽  
K. Basavaiah ◽  
K.B. Vinay
Keyword(s):  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Calibration Graph ◽  
Neutral Medium ◽  
Experimental Conditions ◽  
Colored Product ◽  
Tablet Dosage ◽  
Better Than

A simple visible spectrophotometric method is described for the determination of pantoprazole sodium sesquihydrate (PSS). The method is based on the formation of a brown colored product on treating PSS with permanganate in neutral medium, the absorbance being measured at 350 nm. The experimental conditions for the assay were optimized. The absorbance is found to increase linearly with the concentration of PSS and the calibration graph is linear in the range of 2.5-40.0 ?g ml-1 with a linear regression coefficient of 0.998. The calculated molar absorptivity value is 1.27?104 l mol-1 cm-1 and the corresponding Sandel sensitivity is 0.0341 ?g cm-2. The limits of detection (LOD) and quantification (LOQ) are calculated to be 0.49 and 1.47 ?g ml-1, respectively. Intra-day and inter-day accuracy expressed as relative error were better than 2.0% and the corresponding precision (RSD) was less than 2.5 %. The developed and validated method was applied to the determination of the active ingredient in a tablet dosage form and the results obtained agreed well with those of the reference method. The accuracy and reliability of the method were ascertained by performing recovery experiments via standard-addition procedure.

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 Titrimetric and Spectrophotometric Assay of Pantoprazole in Pharmaceuticals Using Permanganate

2019 ◽  
Vol 53 (1) ◽  
Author(s):  
Kanakapura Basavaiah ◽  
Nagaraju Rajendraprasad ◽  
Kalsang Tharpa ◽  
Urdigere Rangachar Anilkumar ◽  
Salamara Ganeshbhat Hiriyanna ◽  
...  
Keyword(s):  
Standard Addition ◽  
Molar Absorptivity ◽  
Calibration Graph ◽  
Spectrophotometric Assay ◽  
Experimental Conditions ◽  
Accuracy And Precision ◽  
Ich Guidelines ◽  
Sensitivity And Selectivity ◽  
Reaction Stoichiometry

Titrimetric and spectrophotometric assay of pantoprazole sodium (PPS) using permanganate as the oxidimetric reagent is described. In titrimetry, PPS is treated with a measured excess of permanganate in H2SO4 medium followed by the determination of unreacted oxidant by back titrating with a standard iron(II) solution. Spectrophotometry involves addition of a known excess of permanganate to PPS in H2SO4 medium followed by the measurement of absorbance of the residual permanganate at 545 nm. In both the methods, the amount of permanganate reacted corresponds to the PPS content. Experimental conditions that provide wide linear range, maximum sensitivity and selectivity, and accuracy and precisions have been optimized. In titrimetry, the calculations are based on a 1:1 (PPS : KMnO4) reaction stoichiometry and the method is applicable over 1.0-7.0 mg range. In spectrophotometry, Beer’s law is obeyed over the concentration range 15.0-150.0 µg mL-1. The linear regression equation of the calibration graph is A = 0.78 + 0.005 C with a regression coefficient (r) of 0.9982 (n = 11). The apparent molar absorptivity is calculated to be 2.213 × 103 l mol-1cm-1 and the Sandell sensitivity is 0.1954 µg cm-2. The limits of detection (LOD) and quantification (LOQ) calculated as per the ICH guidelines are 0.73 and 2.21 µg mL-1, respectively. Accuracy and precision of the assays were determined by computing the intra-day and inter-day variations at three different levels of PPS; the intra-day and inter-day RSD was < 3.09 % and the accuracy was better than 3.5 %. The methods were successfully applied to the determination of PPS in three different brands of tablets with good accuracy and precision, and without detectable interference by excipients. The accuracy was further ascertained by placebo blank and synthetic mixture analyses and also by recovery experiments via standard-addition procedure.

scholarly journals Colorimetric Assay of Thiamine Hydrochloride in Pharmaceutical Preparations

2019 ◽  
Vol 16 (4) ◽  
pp. 0898
Author(s):  
Ahmad Et al.
Keyword(s):  
Colorimetric Assay ◽  
Pharmaceutical Preparations ◽  
Aldehyde Group ◽  
Molar Absorptivity ◽  
Thiamine Hydrochloride ◽  
Schiff’S Base ◽  
Colored Complex ◽  
Relative Standard ◽  
Primary Amino

            A simple, rapid, accurate and sensitive spectrophotometric method for the determination of thiaminehydrochloride has been developed. The method is based on the formation of the Schiff’s base between the primary amino group present in thiamine hydrochloride and aldehyde group present in the vanillin reagent to produce a yellow colored complex having maximum absorption at 390 nm. Beer’s law has obeaid over the concentration range of 2-28µg/mL, with molar absorptivity of 0.96x104L/mol.cm. The average recovery which is a measure of accuracy is 100±1.3% and the relative standard deviation (RSD) is less than1.5 .The present method is considered to be simple because it does not need heating, hydrolysis and solvent extraction steps. The ingredients often formulated with thiamine and have been shown not to interfere, and is suitable for the routine determination of thiamine hydrochloride. The proposed method has been successfully applied for the determination of thiamine hydrochloride in pure form and in pharmaceutical preparations.

Extractive Spectrophotometric Method for the Determination of Glibenclamide by Ion-Pair Complex in Pure Form and Pharmaceutical Formulation

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
RUAA MUAYAD MAHMOOD ◽  
HAMSA MUNAM YASSEN ◽  
SAMAR , NAJWA ISSAC ABDULLA AHMED DARWEESH ◽  
NAJWA ISSAC ABDULLA
Keyword(s):  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Ion Pair ◽  
Pharmaceutical Formulation ◽  
Ratio Method ◽  
Colored Complex ◽  
Colored Product ◽  
Method Of Continuous Variation ◽  
Job's Method

Simple, rapid and sensitive extractive spectrophotometric method is presented for the determination of glibenclamide (Glb) based on the formation of ion-pair complex between the Glb and anionic dye, methyl orange (MO) at pH 4. The yellow colored complex formed was quantitatively extracted into dichloromethane and measured at 426 nm. The colored product obeyed Beer’s law in the concentration range of (0.5-40) μg.ml-1. The value of molar absorptivity obtained from Beer’s data was found to be 31122 L.mol-1.cm-1, Sandell’s sensitivity value was calculated to be 0.0159 μg.cm-2, while the limits of detection (LOD) and quantification (LOQ) were found to be 0.1086 and 0.3292 μg.ml-1, respectively. The stoichiometry of the complex created between the Glb and MO was 1:1 as determined via Job’s method of continuous variation and mole ratio method. The method was successfully applied for the analysis of pharmaceutical formulation.

scholarly journals New Diazo Coupling Reactions for Visible Spectrophotometric Determination of Alfuzosin in Pharmaceutical Preparations

2007 ◽  
Vol 4 (4) ◽  
pp. 496-501 ◽  
Author(s):  
M. Vamsi Krishna ◽  
D. Gowri Sankar
Keyword(s):  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Basic Medium ◽  
Coupling Reactions ◽  
Acetyl Acetone ◽  
Diazo Coupling ◽  
Optimum Reaction ◽  
Diazonium Ion

Simple, rapid and sensitive spectrophotometric procedures were developed for the analysis of Alfuzosin hydrochloride (AFZ) in pure form as well as in pharmaceutical formulations. The methods are based on the reaction of AFZ with nitrite in acid medium to form diazonium ion, which is coupled with ethoxyethylenemaleic ester (Method A) or ethylcyanoacetate (Method B) or acetyl acetone (method C) in basic medium to form azo dyes, showing absorption maxima at 440, 465 and 490 nm respectively. Beer’s law is obeyed in the concentration of 4-20 μg/mL of AFZ for methods A, B and 3-15 μg/mL of AFZ for method C. The molar absorptivity and sandell’s sensitivity of AFZ- ethoxyethylenemaleic ester, AFZ- ethylcyanoacetate and AFZ-acetyl acetone are1.90 × 104, 0.022; 1.93 × 104, 0.021 and 2.67 × 104L mole-1cm-1, 0.015 μg cm-2respectively. The optimum reaction conditions and other analytical parameters were evaluated. The methods were successfully applied to the determination of AFZ in pharmaceutical formulations.

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.

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