Fast determination of ethambutol in pharmaceutical formulations using capillary electrophoresis with capacitively coupled contactless conductivity detection

Author(s)

Fracassi da Silva, Jose Alberto ^{[1, 2]} ; de Castro, Nathan Vitorazzi ^[1] ; de Jesus, Dosil Pereira ^{[1, 2]} ; Faria, Adriana F. ^[3] ; De Souza, Marcus V. N. ^[4] ; Leal de Oliveira, Marcone Augusto ^[3]

Affiliation

^[1] Univ Estadual Campinas, Inst Chem, BR-13083970 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Inst Nacl Ciencia & Tecnol Bioanalit, BR-13083970 Campinas, SP - Brazil

^[3] Univ Fed Juiz Fora, Inst Ciencias Exatas, Dept Quim, Juiz De Fora - Brazil

^[4] Fundacao Oswaldo Cruz, Inst Tecnol Farmacos Far Manguinhos, Rio De Janeiro - Brazil

• Document type: Journal article
• Source: ELECTROPHORESIS; v. 31, n. 3, p. 570-574, FEB 2010.
• Web of Science Citations: 14

Abstract

A method for the determination of ethambutol (EMB), a first-line drug against tuberculosis, based on CE with capacitively coupled contactless conductivity detection is proposed. The separation of EMB and its main product of degradation were achieved in less than 3 min with a resolution of 2.0 using a BGE composed of 50 mmol/L histidine and 30 mmol/L MES, pH 6.30. By raising the pH to 8.03, the analysis time was reduced to 1.0 min, but with a significant loss of resolution (0.7). Using the best separation 2 conditions, linearity of 0.9976 (R(2) five data points), sensitivity of 1.26 x 10(-4) V min mu mol(-1) L, and LOD and quantification of 23.5 and 78.3 mu mol/L, respectively, were obtained. Recoveries at four levels of concentration ranged from 95 to 102% and the concentration range studied ranged from 100 to 500 mu mol/L. The results obtained for the determination of EMB in pharmaceutical formulations were compared with those obtained by using CE with photometric detection. (AU)

• FAPESP's process: 06/07309-3 - Novel analytical strategies for studies involving biomolecules
• Grantee: Elias Ayres Guidetti Zagatto
• Support Opportunities: Research Projects - Thematic Grants