Capillary electrophcretic behaviour and determination of enoxacin in pharmaceutical formulation and human serum

Abstract

Enoxacin [ENX] is a synthetic broad spectrum antibiotic, which belongs to the fluoroquinolone's family. In this study, a capillary electrophoretic method with UV detection was described for the determination of ENX in pharmaceutical preparation and human serum. The studies were carried out in a fused silica capillary (ID = 75 µm, L = 88 cm, 1 = 58 cm) with a 20 mM borate buffer pH 8.6 at a potential of 30 kV. The best results were obtained with a vacuum injection of 1 s using acetylpipernidic acid as an internal standard (IS). Detection was performed at 265 nm where ENX and IS were absorbing the light equivalently. Under these conditions, the migration times of ENX and IS were 5.3 and 6.1 min, respectively. Well correlated calibration equation was obtained and the analysis of ENX was achieved in tablets. According to the statistical evaluations of the pharmaceutical analysis, average quantification of a tablet, the relative standard deviation and the limit of detection (S/N = 3) were calculated to be, in turn, 106.1% , 1.3 % and 3.5×106 M . The ENX analysis was realized in serum by standard addition method. The proteins of serum were precipitated by two times of ethanol volume. It was centrifuged and the supernatant was directly injected. No interferences were detected and the recovery was found to be 89.7 %. Furthermore, as a comparative method, reversed-prase HPLC procedure was conducted using a mobile phase of phosphate buffer pH 4 and acetonitrile (85:15) and detection at 260 nm. Features of the proposed method compared to HPLC include simplicity, rapidity of operation and low costs. Considering the results, it was concluded that capillary dectrophoresis for the extermination of ENX is a promising method covering the rutin pharmaceutical, pharmacokinetic and bioavailibilhy studies.