Capillary electrophoretic method for the determination of etodolac in pharmaceutical tablet formulation

Abstract

Etodolac (ETO) is a nonsteroidal anti-inflammatory drug with anti-inflammatory, analgesic, and antipyretic activities. A capillary electrophoretic method for the determination of etodolac in a pharmaceutical preparation is described. ETO and diflunisal as an internal standard (IS) were well migrated in the background electrolyte of 10 mM borate at pH 9.3, using a fused silica capillary. The separation was achieved by applying 25 kV, detecting at 226 nm, and injecting the sample for 0.5 s. The average migration times tm (relative standard deviation percentage) of ETO and IS were 7.1 (0.4) and 8.3 (0.5) min, respectively. Highly repeatable results were also obtained for areas of the peaks and peak normal- ization ratio (PNETO/PNIS). Well-correlated linearity was found in a concentration range of 1 × 10-5-2 × 10-4 M. Intraday and interday calibration studies were performed, and reliable results were obtained. Limit of detection and limit of quantitation were 3.2 × 10-6 and 9.7 × 10-6 M, respectively. The proposed method was successfully applied for the analysis of etodolac in the pharmaceutical tablet formulation. The method proved to be simple, reproducible, precise, and fast, since analysis can be performed in less than 10 min.