Ethambutol analysis by copper complexation in pharmaceutical formulations: spectrophotometry and crystal structure

Journal of the Brazilian Chemical Society

Vasconcelos, Juliana P¹  Marcellos, Luiza F¹  Oliveira, Marcone A. L. de¹  Souza, Marcus V. N. de¹  S. Júnior, Antônio L¹  Diniz, Renata¹  Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil¹  Faria, Adriana F¹  Carmo, Weberton R. do¹  Fundação Oswaldo Cruz, Rio de Janeiro, Brazil¹ 

关键词: ethambutol;    complexation;    spectrophotometry;    crystal structure;   

DOI  :  10.1590/S0103-50532011000500008

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

An alternative method for ethambutol (ETB) determination by UV spectrophotometry in pharmaceutical formulations using ETB complexation with Cu(II) was optimized employing a 32 full experimental design having Cu(II) and aqueous acetic acid/sodium acetate buffer at pH 4.6 as variables. The predominant complex stoichiometry in aqueous buffer solution at this pH and formation constant were obtained by using Job's method and Scatchard diagram, respectively. The complex crystalline structure of monocrystal was obtained by X-ray diffraction. The developed method was applied to the pharmaceutical formulation analysis being found: 408.0 ± 11.9 mg of ETB·2HCl, recovery range of 100.9-104.0% and detection and quantification limits of 0.8 and 2.8 mg L-1, respectively. The spectrophotometric method was compared to zone capillary electrophoresis and no significant difference was found within the 95% confidence interval.

【 授权许可】

Unknown