scholarly journals Spectrophotometric Determination of Phenylephrine Hydrochloride in Pharmaceutical Preparations by Oxidative Coupling Reaction

2020 ◽  
Vol 10 (03) ◽  
pp. 323-327
Author(s):  
Ahmed Hamdi Hattab ◽  
Abdul Majeed Khorsheed Ahmed ◽  
Sunbul M. Anwar
Keyword(s):  
Oxidative Coupling ◽  
Pharmaceutical Preparations ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Simple Condition ◽  
First Line ◽  
Phenylephrine Hydrochloride ◽  
Oxidative Coupling Reaction ◽  
Prevention And Treatment

Phenylephrine is a medication mainly applied as a decongestant to relieve hemorrhoids, increase blood pressure, and dilate the pupil. It is the first-line choice for prevention and treatment of hypotension during spinal anesthesia for cesarean section. However, many methods were used for the determination of this drug and its properties. This paper proposes a method that uses N, N dimethyl-p-phenylenediamine dihydrochloride as a new chromogenic reagent (NNDPH). This method is based on the oxidative coupling reaction of phenylephrine with N, N dimethyl-p-phenylenediamine dihydrochloride with ferric chloride in basic media to form green-blue soluble dye product. The outcomes demonstrate that the maximum absorption is at 680 nm, molar absorptivity of 5.54 × 103 mol-1.cm-1, and Sandell’s sensitivity of 0.038 μg.cm-2. The concentration range of 4 to 22 μg.mL-1 of the product is conformable to Beer’s law. Furthermore, it is applied successfully for estimating the drug properties on a simple condition or pharmaceutical preparations.

scholarly journals Indirect spectrophotometric Indirect spectrophotometric determination of chlordiazepoxide in pharmaceutical formulations via oxidative coupling reaction with phenothiazine

2018 ◽  
pp. 7-14
Author(s):  
Hind Hadi ◽  
Mariam Jamal
Keyword(s):  
Oxidative Coupling ◽  
Coupling Reaction ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Calibration Plot ◽  
Pharmaceutical Dosage Forms ◽  
Oxidative Coupling Reaction ◽  
Formed Product

Abstract A sensitive, precise and reliable indirect spectrophotometric method for the determination of chlordiazepoxide (CDE) in pure and pharmaceutical dosage forms is described. The method is based on oxidative coupling reaction between amino group resulting from acidic decomposition of CDE with phenothiazine in the presence of sodium periodate to produce an intense green soluble dye that is stable and shows a maximum absorption at 602 nm. The calibration plot indicates that Beer’s law is obeyed over the concentration range of 0.1?50 µg/mL, with a molar absorptivity of 1×104 L/mol cm and correlation coefficient of 0.9994.All the conditions that affecting on the stability and sensitivity of the formed product were studied and optimized and the suggested method was effectively applied for the determination of CDE in commercial dosage forms.

scholarly journals Spectrophotometric Methods for the Assay of Pyrilamine Maleate Using Chromogenic Reagents

2010 ◽  
Vol 7 (4) ◽  
pp. 1507-1513 ◽  
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.

scholarly journals A novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with MBTH and potassium ferricyanide

2021 ◽  
Vol 5 (1) ◽  
pp. 51-58
Author(s):  
Safwan Ashour
Keyword(s):  
Oxidative Coupling ◽  
Colorimetric Method ◽  
Standard Free Energy ◽  
Coupling Reaction ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Potassium Ferricyanide ◽  
Colorimetric Determination ◽  
Oxidative Coupling Reaction

A new and direct colorimetric method has been established for the determination of catecholamine (methyldopa, MD) in both pure form and in pharmaceutical formulations. The method is based on the oxidative coupling reaction of MD with 3-methyl-2-benzothiazolinone hydrazone hydrochloride monohydrate (MBTH) and potassium ferricyanide at pH 10.4 in aqueous medium to form an orange product that has a maximum absorption at 460 nm. Beer's law plot showed good correlation in the concentration range of 1.0−56.0 µg mL-1, with detection limit of 0.31 µg mL-1. Molar absorptivity for the above method was found to be 6.56×103 L mol-1 cm-1. All the measurements were carried out at 25 ± 1.0 °C, the formation constant (logKf) value of colored species is 9.48 and the standard free energy (DG‡) is − 54.09 KJ mol-1. This method was applied successfully to determination of MD in tablets and the results were compared with the USP method. Common excipients used as additives in tablets do not interfere in the proposed method. The method is accurate, precise and highly reproducible, while being simple, cheap and less time consuming and hence can be suitably applied for routine analysis of MD in bulk and dosage forms.

scholarly journals Spectrophotometric Determination of Bisacodyl in Pure and Pharmaceutical Preparation via Oxidative Coupling Organic Reaction

2017 ◽  
Vol 14 (1) ◽  
pp. 181-188
Author(s):  
Baghdad Science Journal
Keyword(s):  
Oxidative Coupling ◽  
Pharmaceutical Preparation ◽  
Pharmaceutical Preparations ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Water Soluble ◽  
Alkaline Media ◽  
Oxidative Coupling Reaction ◽  
Relative Standard ◽  
Limit Of Quantitation

A simple, accurate and sensitive spectrophotometric way is used to determine Bisacodyl in pure and pharmaceutical preparations. The proposed method depends on using 2,4-Dinitrophenylhydrazine as chromogenic reagent . The method was based on the oxidative coupling reaction of Bisacodyl with 2,4-Dinitrophenylhydrazine with Sodium periodate in the presence of sodium hydroxide as alkaline media to form red water soluble dye product , that has a maximum absorption at ?max 522nm . Beer ,s law is obeyed in the concentration of (2.00–20.00) ?g.ml -1 .The molar absorptivity is (6505) L.mol-1.cm-1,a sandall sensitivity of(0.0555) ?g.cm-2), correlation coefficient of (0.9970) , Limitof detection (LOD) (0.0312 ?g.ml-1), limit of Quantitation (LOQ) (0. 3125 ?g.ml-1) and the relative standard deviation of RSD% (1.6). The method gave a successful determination for Bisacodyl in pharmaceutical preparations and the value of recovery % was better than (100.16%)

Spectrophotometric determination of Drug Clonazepam in Pure form and Pharmaceutical Tablets by Oxidative Coupling Reaction with Chlorpromazine hydrochloride

2019 ◽  
Vol 10 (02) ◽  
Author(s):  
Nahlah Salman Saddam ◽  
K H Kadhim
Keyword(s):  
Oxidative Coupling ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Pure Form ◽  
Chlorpromazine Hydrochloride ◽  
Pharmaceutical Tablets ◽  
Spectrophotometric Methods ◽  
Oxidative Coupling Reaction ◽  
Quantification Limit

Sensitive, simple and a Precise spectrophotometric methods were development for the estimation reduced clonazepam (CZP) in purity form and in the pharmaceutical tablets from through using potassium bromate as oxidizing reagent for the drug and Chlorpromazine Hydrochloride (CPZ.HCL) as new chromogenic reagent. That led to forms colored products with a maximum absorbance of 530 nm. For the conditions reaction have been studied and optimized. The linearity range for Clonazepam was 0.05–3.5 μg/ ml, while the detections limit 0.0061 and the quantification limit 0.020 μg ml-1. The Molar Absorptivity 1.381×104 L/ mol cm with Shandell's sensitivity 0.0228 μg. cm-2. Finally the proposed methods were successfully Appling for estimation CZP in pure form and commercial formulations.

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 Spectrophtometric determination of Hydrochlorothiazaide by oxidative coupling with O-Phenylendiamine

2019 ◽  
Vol 24 (2) ◽  
pp. 46
Author(s):  
Rahma Abdul Hameed Hasan1 ◽  
Ali Ibraheem Khaleel2
Keyword(s):  
Oxidative Coupling ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Water Soluble ◽  
Sensitivity Index ◽  
Medium Ph ◽  
Oxidative Coupling Reaction ◽  
Stable Product ◽  
Orange Color

This study includes the development of a new sensitive spectrophotometric method for the determination of a hydrochlorothaizide in aqueous solution and pharmaceultical preparations. The method is based on the oxidative coupling reaction of hydrochlorothaizide with O-phenylendiamine reagent in a acidic medium pH 1.5 in the presence of potassium ferricyanide  to produce an intense orange color, water soluble and stable product , which exhibits maximum absorption at 450 nm. Beer’s law is obeyed over the concentration arange 6 to 48 µg.ml-1 of hydrochlorothaizide, with a molar absorptivity of  3602.17  L.mo1-1 .cm -1 , Sandell’s sensitivity index of 0.03 µg.cm-2 , relative error range not more than 0.215% , and D.L 0.0835µg.ml-1 . The method has been successfully applied for the determination of hydrochlorothaizide in tablets.   http://dx.doi.org/10.25130/tjps.24.2019.030

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