Oxidative Coupling-Base Reaction for the Indirect Spectrophotometric Determination of Paracetamol in Drug Formulations

2021 ◽  
Vol 3 (1) ◽  
pp. 72-78
Author(s):  
Enas Samer Thanoon ◽  
Lana Abdhameed Raheed ◽  
Imad Younus Hasan
Keyword(s):  
Detection Limit ◽  
Spectrophotometric Method ◽  
Oxidative Coupling ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Products ◽  
Molar Absorptivity ◽  
Drug Formulations ◽  
Figures Of Merit ◽  
Hydrolysis Of

A simple, rapid, and specific spectrophotometric method was developed for the determination of paracetamol  in pure form and drug formulations. The method depended on the hydrolysis of paracetamol to p-aminophenol, which, oxidized under the effect of dissolved oxygen to benzoquinoneimine. In the alkaline medium, benzoquinoneimine reacts with Methyldopa to produce a high stabile indophenol dye. The absorbance was measured at 580 nm, and the molar absorptivity was found to be 7.75 x 10-5 L/(mol cm). Paracetamol was determined in pharmaceutical products in the 10–100 μg.mL-1 concentration range with a detection limit of 1.5 μg.mL-1 PAP. The developed method can be applied to the determination of both paracetamol and p-aminophenol in the presence of each other without prior separation. The proposed method is successfully employed for the determination of paracetamol in various synthetic mixtures and pharmaceutical preparations. Our obtained results were statistically compared with those given by the similar methods and the procedures evaluated as regards to both figures of merit and ease of applicability.

scholarly journals Spectrophotometric determination of nicradipine and isradipine in pharmaceutical formulations

2009 ◽  
Vol 15 (2) ◽  
pp. 69-76 ◽  
Author(s):  
S.M. Al-Ghannam ◽  
A.M. Al-Olyan
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Reaction Pathway ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Zinc Powder ◽  
Conditional Stability ◽  
Conditional Stability Constant

A sensitive spectrophotometric method was developed for the determination of some 1,4-dihydropyridine compounds namely, nicardipine and isradipine either in pure form or in pharmaceutical preparations. The method is based on the reduction of nicardipine and isradipine with zinc powder and calcium chloride followed by further reduction with sodium pentacyanoaminoferrate (II) to give violet and red products having the absorbance maximum at 546 and 539 nm with nicardipine and isradipine, respectively. Beer's law was obeyed over the concentration range 8.0-180 ?g/ml with the detection limit of 1.67 ?g/ml for nicardipine and 8.0-110 ?g/ml with the detection limit of 1.748 ?g/ml for isradipine. The analytical parameters and their effects on the reported methods were investigated. The molar absorptivity, quantization limit, standard deviation of intercept (Sa), standard deviation of slope (Sb) and standard deviation of the residuals (Sy/x) were calculated. The composition of the result compounds were found 1:1 for nicardipine and 1:2 for isradipine by Job's method and the conditional stability constant (Kf) and the free energy changes (?G) were calculated for compounds formed. The proposed method was applied successfully for the determination of nicardipine and isradipine in their dosage forms. The results obtained were in good agreement with those obtained using the reference or official methods. A proposal of the reaction pathway was presented.

scholarly journals Spectrophotometric Determination ofN-Acetyl-L-Cysteine andN-(2-Mercaptopropionyl)-Glycine in Pharmaceutical Preparations

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Lea Kukoc-Modun ◽  
Njegomir Radić
Keyword(s):  
Regression Analysis ◽  
Detection Limit ◽  
Correlation Coefficient ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Pharmaceutical Preparations ◽  
Complexation Reaction ◽  
Calibration Data ◽  
Pharmaceutical Excipients

A simple spectrophotometric method for the determination ofN-acetyl-L-cysteine (NAC) andN-(2-mercaptopropionyl)glycine (MPG) in pharmaceutical preparations was developed, validated, and used. The proposed equilibrium method is based on a coupled two-step redox and complexation reaction. In the first step, Fe(III) is reduced to Fe(II) by NAC or MPG. Subsequently, Fe(II) is complexed with 2,4,6-tripyridyl-s-triazine (TPTZ). Several analytical parameters of the method were optimized for NAC and MPG analysis in the concentration range from 1.0 μM to 100.0 μM. Regression analysis of the calibration data showed a good correlation coefficient (0.9999). The detection limit of the method was 0.14 μM for NAC and 0.13 μM for MPG. The method was successfully applied to quantify NAC and MPG in pharmaceutical preparations. No interferences were observed from common pharmaceutical excipients.

scholarly journals Spectrophotometric Determination of Famciclovir and Racecodotril Using 2, 6-Dichloroquinone–Chlorimide

2007 ◽  
Vol 4 (1) ◽  
pp. 50-52 ◽  
Author(s):  
M. Vamsi Krishna ◽  
P. V. Madhavi Latha ◽  
D. Gowri Sankar
Keyword(s):  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Oxidative Coupling ◽  
Pharmaceutical Preparations ◽  
Coupling Product ◽  
Beer's Law ◽  
Beer’S Law ◽  
Sensitive Spectrophotometric Method

A simple, sensitive spectrophotometric method for the determination of Famciclovir and Racecodotril is developed. It is based on the formation of a colored oxidative coupling product between 2,6-dichloroquinone-chlorimide and the drug is described. The method has been extended to pharmaceutical preparations. The absorption maxima and Beer’s law limits for Famciclovir are 500 nm, 20-100 µg/mL and for Racecodotril are 460 nm, 12.5-62.5 µg/mL.

scholarly journals Spectrophotometric Determination of Palladium(II) Ions Using a New Reagent: 4-(N’-(4-Imino-2-oxo-thiazolidine-5-ylidene)-hydrazino)-benzoic Acid (p-ITYBA)

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Oleksandr S. Tymoshuk ◽  
Orest S. Fedyshyn ◽  
Lesia V. Oleksiv ◽  
Petro V. Rydchuk ◽  
Vasyl S. Matiychuk
Keyword(s):  
Detection Limit ◽  
Complex Formation ◽  
Benzoic Acid ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Water Medium ◽  
Analytical Reagent ◽  
Optimal Ph

The simple, rapid spectrophotometric method for palladium(II) ions determination using a new analytical reagent is described. The interaction of Pd(II) ions with a reagent, of the class of azolidones, 4-(N′-(4-imino-2-oxo-thiazolidine-5-ylidene)-hydrazino)-benzoic acid, in water medium results in the formation of a complex. The Pd(II)-p-ITYBA complex shows maximum absorbance at a wavelength of 450 nm. The molar absorptivity is 4.30 × 103 L·mol−1·cm−1. The optimal pH for complex formation is 7.0. The developed method has a wide linearity range of 0.64–10.64 µg·mL−1 for Pd(II). The detection limit is 0.23 µg·mL−1. It was found that Co(II), Ni(II), Zn(II), Fe(III), Cu(II), Al(III), and many anions do not interfere with the Pd(II) determination. The proposed method was tested in the analysis of model solutions and successfully applied for the determination of palladium in catalyst. The obtained results show that this method can be used for serial determinations of palladium in various objects.

A supersensitive spectrophotometric method for the determination of uranium(VI) with eriochromazurol B in the presence of tensides

1984 ◽  
Vol 49 (9) ◽  
pp. 1974-1989 ◽  
Author(s):  
Milan Pištělka ◽  
Bohumil Stojek ◽  
Josef Havel
Keyword(s):  
Detection Limit ◽  
Dicarboxylic Acid ◽  
Aqueous Phase ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Methods Of Determination ◽  
Spectrophotometric Methods

The influence of various tensides on the sensitivity of the reaction of uranyl with chromatographically pure Eriochromazurol B (2'',6''-dichloro-3,3'-dimethyl-4-hydroxyfuchsone-5,5'-dicarboxylic acid) was studied and considerable bathochromic and hyperchromic effects were observed. The reaction is most sensitive in the presence of cetyltrimethylammonium or certylpyridinium bromide. Based on the study of the equlibria and optimization of the conditions, a method is suggested for the determination of uranium traces in waters consisting in the measurement of absorbance at 624 nm at pH 5. With the molar absorptivity value of 136 000, the method ranks among the most sensitive spectrophotometric methods of determination of uranium in general. The uranium traces in waters can conveniently be extracted with tri-n-octylamine and reextracted into an aqueous phase. For 10 ml samples, the detection limit is 0.025 ppm uranium. The results obtained are evaluated statistically.

scholarly journals Spectrophotometric determination of methyldopa in pharmaceutical formulations

2005 ◽  
Vol 30 (3) ◽  
pp. 23-28 ◽  
Author(s):  
P. R. S. Ribeiro ◽  
L. Pezza ◽  
H. R. Pezza
Keyword(s):  
Correlation Coefficient ◽  
Spectrophotometric Method ◽  
Confidence Level ◽  
Low Cost ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Pharmaceutical Products ◽  
Complexation Reaction ◽  
Excellent Correlation

A new, simple, precise, rapid and low-cost spectrophotometric method for methyldopa determination in pharmaceutical preparations is described. This method is based on the complexation reaction of methyldopa with molybdate. Absorbance of the resulting yellow coloured product is measured at 410 nm. Beer's Law is obeyed in a concentration range of 50 - 200 µg ml-1 methyldopa with an excellent correlation coefficient (r = 0.9999). No interference was observed from common excipients in formulations. The results show a simple, accurate, fast and readily applied method to the determination of methyldopa in pharmaceutical products. The analytical results obtained for these products by the proposed method are in agreement with those of the Brazilian Pharmacopoeia procedure at 95% confidence level.

scholarly journals Spectrophotometric method for determination of ranitidine hydrochloride in bulk and in pharmaceutical preparation using ninhydrin

2020 ◽  
Vol 11 (4) ◽  
pp. 291-297
Author(s):  
Hutaf Mustafa Baker ◽  
Hussam Ahmad Alsaoud ◽  
Hamzeh Mohamad Abdel-Halim
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Preparation ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Limit Of Quantification ◽  
Ranitidine Hydrochloride ◽  
Relative Standard ◽  
Reproducible Method

A simple, sensitive and reproducible method for the determination of ranitidine hydrochloride in pharmaceutical preparations was investigated. This spectrophotometric method was based on the formation of a deep red color product with ninhydrin in basic media and the absorbance measured at λmax = 480 nm. The reaction occurs at 45 °C with pH = 10 having a contact time of 38 minutes. Under the optimum conditions, Beer’s Law is obeyed in the concentration range of 8.98×103 - 9.90×104 µg/L. The coefficient of correlation was found to be 0.999 for the obtained method with molar absorptivity of 3.05×103 L/mol.cm. The calculated Sandell’s sensitivity is 0.108 μg/cm2. The limit of detection and limit of quantification are 0.0997 and 0.3023 µg/mL, respectively. The low values of the percentage relative standard deviation and percentage relative error indicate the high precision and the good accuracy of the proposed method. The stoichiometry of the reaction is determined and found to be 1:4 (Ranitidine hydrochloride:Ninhydrin). The initial rate method confirmed that this reaction is first order one.

scholarly journals Spectrophotometric Determination of Mesalazine in Pharmaceutical Preparations by Oxidative Coupling Reactions with m-Aminophenol and 2,6- Dihydroxybenzoic Acid

2019 ◽  
Vol 16 (4(Suppl.)) ◽  
pp. 1010
Author(s):  
Aziz Et al.
Keyword(s):  
Oxidative Coupling ◽  
Pharmaceutical Preparations ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Basic Medium ◽  
Coupling Reactions ◽  
Dihydroxybenzoic Acid ◽  
Sodium Metaperiodate ◽  
Medium Method

     Tow simple, rapid and sensitive spectrophotometric methods for the determination of mesalazine in pharmaceutical preparations have been carried out. The proposed methods depend on oxidative coupling reaction of mesalazine with m-aminophenol in the existence of N-bromosuccinamide in alkaline medium (method A) and 2,6-dihydroxybenzoic acid in the existence of sodium metaperiodate in basic medium (method B) to produce colored products , show highest absorptions at 640 (nm) and 515 (nm), alternately. Beer’s law was consistent in concentrations extent of 1.25-30 and 0.5-12.5 (µg.mL-1) with molar absorptivity of 0.36×104 and 0.77×104 L.mol-1.cm-1, alternately. The limits of detection (LOD) were 0.0144 and 0.0829   µg.mL-1, while limits of quantitation (LOQ) were 0.0483 and 0.2766 (µg.mL-1), alternately. The suggested methods have been applied successfully to the determination of mesalazine in its pharmaceutical preparations as tablets and suppositories.

scholarly journals DEVELOPMENT AND VALIDATION OF SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF DPP-4 INHIBITOR, SITAGLIPTIN, IN ITS PHARMACEUTICAL PREPARATIONS

2018 ◽  
Vol 35 (3) ◽  
pp. 45
Author(s):  
C. Bala Sekaran ◽  
A. Prameela Rani
Keyword(s):  
Spectrophotometric Method ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Amino Group ◽  
Reaction Conditions ◽  
Colored Product ◽  
Primary Amino ◽  
Development And Validation

A simple, sensitive and reproducible spectrophotometric method was developed for the determination of sitagliptin phosphate in bulk and in pharmaceutical formulations. The proposed method is based on condensation of the primary amino group of sitagliptin phosphate with acetyl acetone and formaldehyde producing a yellow colored product, which is measured spectrophotometrically at 430nm. The color was stable for about 1 hour. Beer’s law is obeyed over a concentration range of 5-25 μg/ml. The apparent molar absorptivity and Sandell sensitivity values are 1.067 x 104 Lmol-1cm-1 and 0.0471 μgcm-2 respectively. All the variables were studied to optimize the reaction conditions. No interference was observed in the presence of common pharmaceutical excipients. The validity of the method was tested by analyzing sitagliptin phosphate in its pharmaceutical preparations. Good recoveries were obtained. The developed method was successfully employed for the determination of sitagliptin phosphate in various pharmaceutical preparations.

scholarly journals Leishman’s Dye as a Novel Reagent in Spectrophotometric Determination of Chloramphenicol

2020 ◽  
Vol 10 (02) ◽  
pp. 250-254
Author(s):  
Jamal Sudad Raeek Othman Nabeel Sabeeh
Keyword(s):  
Spectrophotometric Method ◽  
Acidic Medium ◽  
Pharmaceutical Preparations ◽  
High Sensitivity ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Sensitivity Index ◽  
Oxidizing Agent ◽  
Drug Compounds

By reviewing the literature, there is no indication concerning the use of Leishman’s dye in evaluating drug compounds by dye-color bleaching; hence, it is the first attempt to use Leishman’s dye as a novel reagent in the estimation of chloramphenicol (CAP) by an indirect spectrophotometric method in bulk and in its pharmaceutical preparations. The method includes the use of a great amount of N-bromosuccinamide (NBS) in the acidic medium as an oxidizing agent of the drug under investigation (CAP), and then using the residual of NBS for Leishman’s dye color bleaching. The absorbance has been measured at 622 nm (the maximum absorption of Leishman’s dye). A linear relationship was obtained for the Beer’s law with the concentration ranges from 10 to 250 μg/10 mL with acceptable values of molar absorptivity 0.58 × 104 L.mol-1.cm-1 and 0.055 μg.cm-2 of Sandell’s sensitivity index, which mean a high sensitivity. An approved estimation of CAP in its various pharmaceutical formulations was found.

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