Capillary electrophoresis analysis of gabapentin and vigabatrin in pharmaceutical preparations as ofloxacin derivatives

Gabapentin (GBP) and vigabatrin (VGB) are widely used anticonvulsants. In structure, they are amino carboxylic compounds, which lack practical chromophoric groups for detection by absorption spectrophotometry. Derivatization of gabapentin and vigabatrin with chromophoric ofloxacin acyl chloride (OAC) was performed and the resulting OAC derivatives can be analyzed by simple capillary zone electrophoresis (CZE) with UV detection (300 nm). The detection limit (S/N = 3, injection 3 s) of the method for the gabapentin or vigabatrin was 5 (mu)M. Application of the method to the analysis of gabapentin and vigabatrin in pharmaceutical preparations proved simple and feasible. The precision (relative standard deviation) and accuracy (relative error) of the method for intra- and interday analyses of both drugs, in pharmaceuticals, were below 3.1 and 4.8%, respectively.