Cloud-point extraction and spectrophotometric determination of clonazepam in pharmaceutical dosage forms

Abstract

ABSTRACT. Aneco-friendly, simple and very sensitive method was developed for preconcentration and determination of clonazepam (CLO) in pharmaceutical dosage forms using cloud point extraction (CPE) technique. The method is based on cloud point extraction of product from oxidative coupling between reduced CLO and phloroglucinol (PHG) using Triton X-114 as surfactant. The product was extracted by micelles of the non-ionic surfactant (TritonX-114) and subsequently detected spectrophotometrically at specific 543 nm. Under optimal conditions, the linearity of calibration curve was in the range of 0.3-25 µg/mL of CLO (r = 0.9994). Average recoveries for samples were determined to be between 96-101%. The relative standard deviation (RSD) for 3.0 µg/mL of CLO was (2.5%). The limits of detection and quantification were 0.11 and 0.37 µg/mL respectively. The suggested method was applied successfully for determination of CLO in commercial tablets.

Spectrophotometric Determination of Allopurinol by Oxidative Coupling Reaction Using 2-Nitrophenol Reagent in the Presence of N-Bromosuccinimide

“…The absorption spectrum was recorded after 15 minutes for each solution versus its sham solution. The results are recorded in Table (8) and Figure (1). It is clear from the results in the above table that acetone gives the highest absorption of the resulting solution compared to other solvents, but it is preferable to use water for its abundance and cheapness, and for this reason, distilled water was used in subsequent experiments.…”

“…Oxidative Coupling Reactions: The oxidative coupling reaction is one of the most important organic reactions with wide applications, especially in analytical chemistry, and the reaction involves the coupling of two organic substances with the presence of an oxidizing agent under the appropriate reaction conditions, where oxidation of these substances occurs, which leads to the formation of multiple compounds that interact with each other and give a colored product that can be measured spectroscopically. They are used in the quantification of many different organic compounds (1,2) and the oxidative coupling reactions that are electrogenic (4,3) or fluorescent (5) have been widely exploited in the estimation of important compounds, food, environment, clinical and pharmaceutical analyzes by applying different analytical techniques such as Spectroscopic methods (7,6) , fluorescence and chromatographic methods (8) , and flow injection technique (9) Allopurinol: It is a white powder, molecular formula C5H4N4O and molecular weight 136.1 g/mol, slightly soluble in water and ethanol. Scientific name: 1,5-Dihydro-4H-pyrazolo [3,4-d]pyrimidin-4-one…”

Spectrophotometric Estimation of Clonazepam as Pure Form and in its Pharmaceutical Formulation (Tablet) Using Alizarin Red S

“…Several analytical methods have been reported for assay of CLZM in different samples including diazo coupling spectrophotometric methods (Hajir and Kassim, 2020;Ameen and Al-Badry, 2005), Cloud point extraction (CPE) combined with diazocoupling (Abdullah, 2017;Mahdi and Kadhim, 2020), oxidative coupling (Saddam and Kadhim, 2019;Mahdi and Kadim, 2018), charge transfer (Hadi, 2015;Zankanah and Dikran, 2017;Salem et al, 2002), Prussian blue complex (Fadhel and Khamees, 2018), UV-spectrophotometry (Kakde and Satone, 2009;Karajgi et al , 2016), spectrofluorometric (Patel and Chhalotiya, 2017;Belal et al, 2017;Salem et al, 2004).…”

Spectrophotometric Determination for Benzodiazepine Drugs (Clonazepam and Nitrazepam) in Pure and Pharmaceuticals Preparation

“…Several methods have been reported in the literature for the estimation of drugs of clonazepam and nitrazepam in either pharmaceutical forms or biological fluids, including HPLC [9][10][11][12][13][14][15][16], liquid and gas chromatography [17][18][19][20][21][22][23][24], clonazepam in blood using LC-MS/MS [25], chemiluminescence and electrochemiluminescence [26,27], electrical methods [28][29][30][31][32][33][34][35][36], flowinjection [37][38][39][40][41][42], colorimetric and various spectrophotometric methods [43][44][45][46][47][48][49][50][51][52][53][54][55][56]…”