High-performance liquid chromatographic assay for a new fasciolicide agent, αBIOF10, in biological fluids

This paper describes a high-performance liquid chromatographic method with ultraviolet absorbance detection at 304 nm for the determination of 6-chloro-5-(1-naphthyloxy)-2-methylthio benzimidazole (alpha BIOF10) - a new fasciolicide agent and its sulphoxide (SO alpha BIOF10), in plasma and urine. It requires 2 mi of biological fluid, an extraction using Sep-Pak cartridges, and methanol for drug elution. Analysis is performed on a mu Bondapak C-18 (10 mu m) column, using methanol-acetonitrile-water (40:30:30, v/v) as the mobile phase. Results showed that the assay is sensitive: 7.2 ng/ml for alpha BIOF10 and SO alpha BIOF10 in plasma and 3.6 ng/ml for both compounds in urine. The response was linear between 0.195 and 12.5 mu g/ml. Maximum intra-day coefficient of variation was 5.3%. Recovery obtained was 97.8% for both alpha BIOF10 and SOaBIOF10. In urine, recovery was 99.6% and 93.1% for alpha BIOF10 and SO alpha BIOF10 respectively. The method was used to perform a preliminary pharmacokinetic study in two sheep and was found to be satisfactory. (C) 1998 Elsevier Science B.V. All rights reserved.