scholarly journals Determination of penicillamine, tiopronin and glutathione in pharmaceutical formulations by kinetic spectrophotometry

2021 ◽  
Vol 71 (4) ◽  
pp. 619-630
Author(s):  
Lea Kukoc-Modun ◽  
Maja Biocic ◽  
Njegomir Radić

Abstract A novel and simple method for the determination of penicillamine (PEN), tiopronin (mercaptopropionyl glycine, MPG) and glutathione (GSH) in pharmaceutical formulations by kinetic spectrophotometry has been developed and validated. It is based on the redox reaction where the thiol compound (RSH) reduces CuII-neocuproine complex to CuI-neocuproine complex. The non-steady state signal of the formed CuI- neocuproine complex is measured at 458 nm. The initial rate and fixed time (at 1 min) methods were validated. The calibration graph was linear in the concentration range from 8.0 × 10‒7 to 8.0 × 10‒5 mol L−1 for the initial rate method and from 6.0 × 10‒7 to 6.0 × 10−5 mol L−1 for the fixed time method, with the detection limits of 2.4 × 10−7 and 1.4 × 10‒7 mol L−1, resp. Levels of PEN, MPG and GSH in pharmaceutical formulations were successfully assayed by both methods. The advantages of the presented methods include sensitivity, short analysis time, ease of application and low cost.

2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
Mahmoud A. Omar ◽  
Osama H. Abdelmageed ◽  
Tamer Z. Attia

A simple, reliable, and sensitive kinetic spectrophotometric method was developed for determination of eight cephalosporin antibiotics, namely, Cefotaxime sodium, Cephapirin sodium, Cephradine dihydrate, Cephalexin monohydrate, Ceftazidime pentahydrate, Cefazoline sodium, Ceftriaxone sodium, and Cefuroxime sodium. The method depends on oxidation of each of studied drugs with alkaline potassium permanganate. The reaction is followed spectrophotometrically by measuring the rate of change of absorbance at 610 nm. The initial rate and fixed time (at 3 minutes) methods are utilized for construction of calibration graphs to determine the concentration of the studied drugs. The calibration graphs are linear in the concentration ranges 5–15 g  and 5–25 g  using the initial rate and fixed time methods, respectively. The results are validated statistically and checked through recovery studies. The method has been successfully applied for the determination of the studied cephalosporins in commercial dosage forms. Statistical comparisons of the results with the reference methods show the excellent agreement and indicate no significant difference in accuracy and precision.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Joytosh Banerjee ◽  
Renu Solanki ◽  
Badri Prakash Nagori

Two simple and sensitive spectrophotometric methods have been developed for the determination of eperisone hydrochloride based on its ability to be detected in UV region (Normal UV) and its oxidation using potassium permanganate in alkaline medium (kinetic spectroscopic). The detection was done at 261.40 nm and 603.5 nm. The different experimental parameters affecting the method development were studied and optimized. The initial rate and fixed time method were utilized to construct calibration graph, and 5 minutes and 3 minutes, respectively, were found suitable for the determination of the concentration of drug. Linearity was found over the concentration range of 2–20 μg/mL, 15–30 μg/mL, and 15–35 μg/mL by UV, initial rate, and fixed time methods, respectively. The results were validated as per the ICH guidelines. RSD values were found to be less than 2%. The methods were applied for estimation of eperisone hydrochloride in RAPISONE (Abbott, Maharashtra). The assay results were found to be 100.4% ± 0.08, 99.93% ± 0.05, and 99.41% ± 0.04 by UV, initial rate, and fixed time method, respectively. Statistical comparison of the proposed methods showed a good agreement indicating no significant difference in accuracy and precision, thus confirming the suitability of UV and kinetic method for the estimation of eperisone hydrochloride in bulk as well as in tablet dosage forms.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Safwan Ashour ◽  
Mouhammed Khateeb

A simple and sensitive kinetic spectrophotometric method was developed for the determination of fexofenadine hydrochloride in bulk and pharmaceutical preparations. The method is based on a kinetic investigation of the oxidation reaction of fexofenadine using alkaline potassium permanganate as an oxidizing agent at room temperature. The reaction is followed spectrophotometrically by measuring the increase of absorbance owing to the formation of manganate ion at 610 nm. The initial rate and fixed time (at 15 min) methods are utilized for construction of calibration graphs. All the reaction conditions for the proposed method have been studied. The linearity range was found to be 2.5–50.0 μg mL−1 with detection limit of 0.055 μg mL−1 for both initial rate and fixed time methods. The proposed method was applied successfully for the determination of fexofenadine in pharmaceutical formulations; the percentage recoveries were 99.98–101.96%. The results obtained were compared statistically with those obtained by the official method and showed no significant differences regarding accuracy and precision.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 37
Author(s):  
Mayra K. S. Monteiro ◽  
Djalma R. Da Silva ◽  
Marco A. Quiroz ◽  
Vítor J. P. Vilar ◽  
Carlos A. Martínez-Huitle ◽  
...  

This study aims to investigate the applicability of a hybrid electrochemical sensor composed of cork and graphite (Gr) for detecting caffeine in aqueous solutions. Raw cork (RAC) and regranulated cork (RGC, obtained by thermal treatment of RAC with steam at 380 °C) were tested as modifiers. The results clearly showed that the cork-graphite sensors, GrRAC and GrRGC, exhibited a linear response over a wide range of caffeine concentration (5–1000 µM), with R2 of 0.99 and 0.98, respectively. The limits of detection (LOD), estimated at 2.9 and 6.1 µM for GrRAC and GrRGC, suggest greater sensitivity and reproducibility than the unmodified conventional graphite sensor. The low-cost cork-graphite sensors were successfully applied in the determination of caffeine in soft drinks and pharmaceutical formulations, presenting well-defined current signals when analyzing real samples. When comparing electrochemical determinations and high performance liquid chromatography measurements, no significant differences were observed (mean accuracy 3.0%), highlighting the potential use of these sensors to determine caffeine in different samples.


Author(s):  
Mouhammed Khateeb ◽  
Basheer Elias ◽  
Fatema Al Rahal

A simple and sensitive kinetic spectrophotometric method has been developed for the determination of folic acid (FA) in bulk and pharmaceutical Formulations. The method is based on the oxidation of FA by Fe (III) in sulfuric acid medium. Fe (III) subsequently reduces to Fe (II) which is coupled with potassium ferricyanide to form Prussian blue. The reaction is followed spectrophotometrically by measuring the increase in absorbance at λmax 725 nm. The rate data and fixed time methods were adopted for constructing the calibration curves. The linearity range was found to be 1–20 μg mL-1 for each method. The correlation coefficient was 0.9978 and 0.9993, and LOD was found to be 0.91 and 0.09 μg mL-1 for rate data and fixed time methods, respectively. The proposed method has been successfully applied to the determination of FA in formulations with no interference from the excipients. Statical comparison of the results shows that there is no significant difference between the proposed and pharmacopoeial methods


Author(s):  
Akram M. El-didamony ◽  
Moftah A. Moustafa

Objective: Direct and sensitive spectrophotometric method is described for the quantitative determination of some anti-hypertensive drugs such as atenolol (ATN) and timolol (TIM) in pure forms as well as in their dosage forms.Methods: The proposed method is based on the redox reaction between the selected drugs and KMnO4 in alkaline medium. The method involves treating the aqueous solution of the selected drugs with KMnO4 in alkaline medium and measuring the bluish-green product at 610 nm. The different experimental parameters affecting the development and stability of the color were carefully studied and optimized.Results: The fixed-time method is adopted for constructing the calibration curves, which were found to be linear over the concentration ranges of 2.0–14 mg/ml and 2.0–28 mg/ml for ATN and TIM, respectively. The determination of the studied drugs by initial rate, variable time and rate constant method was workable with the calibration equations obtained but the fixed time method has been found to be more applicable.Conclusion: The applicability of the proposed method was demonstrated by the determination of the selected drugs in both pure and in commercial dosage forms and has met the validation requirements.


2013 ◽  
Vol 830 ◽  
pp. 345-348
Author(s):  
Lin Gao ◽  
Sheng Jie Chen ◽  
Fang Chen ◽  
Wen Hong Zhou ◽  
Jun Long Yao

A simple, sensitive, green and low cost detection method based on the cloud point extraction (CPE) separation and spectrophotometry was proposed for the determination of lead. In pH=9.0 H3BO3 buffer solution, Pb(II) reacts with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) in the presence of Triton X-100 yielding a hydrophobic complex, which then is extracted into micro-volume surfactant-rich phase. The calibration graph was linear in the range of 20-400 µg/L (at 560 nm). Under the optimized conditions, the detection limits of 10.94 µg/L and the relative standard deviations(RSD) of 2.0% (n=5) for Lead(II) were found, respectively. The sensitivity and absorbance of this method are at least five times higher when compared with that of usual 5-Br-PADAP spectrophotometry without CPE, and the proposed method has been applied to the determination of Lead in environment water samples with satisfactory results.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Pavagada J. Ramesh ◽  
Kanakapura Basavaiah ◽  
Cijo M. Xavier ◽  
Kudige N. Prashanth ◽  
Madihalli S. Raghu ◽  
...  

Titrimetric and spectrophotometric assay of ganciclovir (GNC) is described using cerium(IV) sulphate as the oxidimetric reagent. The methods are based on the oxidation of GNC with a measured excess of cerium(IV) sulphate in acid medium followed by determination of the unreacted oxidant by two different reaction schemes. In titrimetry, the unreacted oxidant was determined by back titration with ferrous ammonium sulphate (FAS) in sulphuric acid medium, and spectrophotometry involves the reaction of residual cerium(IV) with p-DMAB to form brownish-coloured p-dimethylamino quinoneimine whose absorbance was measured at 460 nm. In both methods, the amount of cerium(IV) sulphate reacted corresponds to GNC concentration. Titrimetry is applicable over 3–10 mg range where as, in spcetrophotometry, the calibration graph is linear over the range of 2–10 μg mL−1 and the calculated molar absorptivity value is  L mol−1 cm−1. The validity of the proposed methods was tested by analyzing pure and dosage forms containing GNC. Statistical treatment of the results reflects that the proposed procedures are precise, accurate, and easily applicable for the determination of GNC pure form and in pharmaceutical formulations.


2010 ◽  
Vol 88 (6) ◽  
pp. 533-539 ◽  
Author(s):  
Larissa Zuppardo Lacerda Sabino ◽  
Daniele Cestari Marino ◽  
Horacio Dorigan Moya

A simple method was developed for determining microquantities of diltiazem, based on the reduction of copper(II) in buffered solution (pH 7.0) and the use of a micellar medium containing 4,4′-dicarboxy-2,2′-biquinoline acid. The copper(I) produced reacts with 4,4′-dicarboxy-2,2′-biquinoline acid and the complexes formed are spectrophotometrically measured at 558 nm. A typical calibration graph shows good linearity (r = 0.993) from 20 to 100 μg mL–1 of diltiazem. The limit of detection and relative standard deviation were calculated as 12 μg mL–1 (99% confidence level) and 3.5% (40 μg mL–1; n = 6), respectively, with a mean recovery value of 96.5% found in pharmaceutical dosages. A straightforward and effective way to recycle the reagents is addressed. The hazardous aspects of the Cu(I)–BCA reaction are presented as well.


2019 ◽  
Vol 16 (3) ◽  
pp. 0595
Author(s):  
ALmashhadani Et al.

          Simple, cheap, sensitive, and accurate kinetic- spectrophotometric method has been developed for the determination of naringenin in pure and supplements formulations. The method is based on the formation of Prussian blue. The product dye exhibits a maximum absorbance at 707 nm. The calibration graph of naringenin was linear over the range 0.3 to 10 µg ml-1 for the fixed time method (at 15 min) with a correlation coefficient (r) and percentage linearity (r2%) were of 0.9995 and 99.90 %, respectively, while the limit of detection LOD was 0.041 µg ml-1. The method was successfully applied for the determination of naringenin in supplements with satisfactory results.


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