Spectrophotometric determination of methyldopa in pharmaceutical formulations

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. Be...

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Detalles Bibliográficos
Autores: Ribeiro, P. R S [UNESP], Pezza, Leonardo [UNESP], Pezza, Helena Redigolo [UNESP]
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2005
País:Brasil
Institución:Universidade Estadual Paulista (UNESP)
Repositorio:Repositório Institucional da UNESP
Idioma:inglés
OAI Identifier:oai:repositorio.unesp.br:11449/68304
Acceso en línea:http://dx.doi.org/10.1590/S0100-46702005000300003
http://hdl.handle.net/11449/68304
Access Level:acceso abierto
Palabra clave:Ammonium molybdate
Methyldopa
Pharmaceuticals formulations
Spectrophotometric determination
Descripción
Sumario: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.