A novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with MBTH and potassium ferricyanide
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 (...
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Format: | Article |
Language: | English |
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Universidade Federal do Rio Grande do Sul
2021-06-01
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Series: | Drug Analytical Research |
Online Access: | https://seer.ufrgs.br/index.php/produto&producao/ojs/index.php/dar/article/view/113058 |
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author | Safwan Ashour |
author_facet | Safwan Ashour |
author_sort | Safwan Ashour |
collection | DOAJ |
description | 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.
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first_indexed | 2024-03-08T02:04:33Z |
format | Article |
id | doaj.art-2915e74138514953ab44d12e538da260 |
institution | Directory Open Access Journal |
issn | 2527-2616 |
language | English |
last_indexed | 2024-03-08T02:04:33Z |
publishDate | 2021-06-01 |
publisher | Universidade Federal do Rio Grande do Sul |
record_format | Article |
series | Drug Analytical Research |
spelling | doaj.art-2915e74138514953ab44d12e538da2602024-02-13T18:14:35ZengUniversidade Federal do Rio Grande do SulDrug Analytical Research2527-26162021-06-0151A novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with MBTH and potassium ferricyanideSafwan Ashour0University of GaziantepA 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. https://seer.ufrgs.br/index.php/produto&producao/ojs/index.php/dar/article/view/113058 |
spellingShingle | Safwan Ashour A novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with MBTH and potassium ferricyanide Drug Analytical Research |
title | A novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with MBTH and potassium ferricyanide |
title_full | A novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with MBTH and potassium ferricyanide |
title_fullStr | A novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with MBTH and potassium ferricyanide |
title_full_unstemmed | A novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with MBTH and potassium ferricyanide |
title_short | A novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with MBTH and potassium ferricyanide |
title_sort | novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with mbth and potassium ferricyanide |
url | https://seer.ufrgs.br/index.php/produto&producao/ojs/index.php/dar/article/view/113058 |
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