The Effect of Fasting on the Plasma Disposition of Albendazole in Goats

Abstract

This study was designed to investigate the effect of fasting on the plasma disposition of albendazole (ABZ) in goats following oral administration. A total of 10 goats, aged 5-6 months were used in this study. The animals were allocated into two groups (fasted and fed groups) of five animals each. ABZ was administered orally to animals in two groups at 10 mg/kg bodyweight. Heparinize blood samples were collected between 1 h and 144 h after treatment and the plasma samples were analysed by high performance liquid chromatography for ABZ, active albendazole sulphoxide (ABZSO) and inactive albendazole sulphone (ABZSO2) metabolites. ABZ is not detected and ABZSO and ABZSO2 metabolites were present in the samples of fed and fasted animals. Feeding was significantly enhanced the plasma concentration of the ABZSO and ABZSO2 metabolites. The area under the curve (AUC) and half-life (t1/2) of both metabolites were significantly larger and longer in fed compared to fasted animals, respectively. Moreover the maximum plasma concentration (Cmax: 1.06±0.17 µg/ml) of ABZSO2 was also significantly higher in fed group compared with the fasting group (0.72±0.20 µg/ml). The changes in plasma kinetics, reflecting an altered quantitative gastrointestinal absorption or metabolism, were reflected in increased availability of ABZ metabolites in the plasma of fed goats. This could be a strategy to extend the exposure of parasites to the more active metabolite of ABZ and thus to improve the efficacy in goats.