RESUMO
The new method for the enantiomeric resolution of various 2-arylpropionic acids by capillary zone electrophoresis (CZE) using heptakis-tri-O-methyl-beta-cyclodextrin as chiral selector was applied to the determination of ketoprofen in different commercially-available pharmaceutical preparations. The analyte was determined under chiral and nonchiral conditions (viz. in the presence and absence of 50 mM heptakis-tri-O-methyl-beta-cyclodextrin in the background electrolyte), with significantly similar results and relative standard deviations from 1.2 to 6.5% in both cases. The limits of detection and determination for the inactive enantiomer, R-(-)-ketoprofen, were calculated to be 7.0 x 10(-7) and 1.6 x 10(-6) M, respectively. The proposed method was successfully used to determine enantiomeric purity in the drugs studied, with results comparable to those provided by the chiral HPLC method.
Assuntos
Anti-Inflamatórios não Esteroides/análise , Eletroforese Capilar/métodos , Cetoprofeno/análise , Preparações Farmacêuticas/química , EstereoisomerismoRESUMO
A method for resolving the enantiomers of various 2-arylpropionic acids (viz. ketoprofen, ibuprofen and fenoprofen) by capillary zone electrophoresis (CZE) using a background electrolyte (BGE) containing a cyclodextrin as chiral selector is proposed. The effects of the type of cyclodextrin used and its concentration on resolution were studied and heptakis-2,3,6-tri- O-methyl-beta-cyclodextrin was found to be the sole effective choice for the quantitative enantiomeric resolution of all the compounds tested. The influence of pH, BGE concentration, capillary temperature and addition of methanol to the BGE on resolution and other separation-related parameters was also studied. The three compounds studied can be enantiomerically resolved with a high efficiency in a short time (less than 20 min) with no capillary treatment. This makes the proposed method suitable for assessing the enantiomeric purity of commercially available pharmaceuticals.
