Studies on the Pharmacokinetics of Furazolidone in Carassius Aurats

Abstract

The pharmacokinetics of furazolidone and its metabolite (AOZ) in carassius aurats were studied by LC-MS after oral dose of 5, 10, 25 μ g/g for 2, 6, 12, 24, 48, 72, 96, 120, 360 and 480 h, respectively. The results showed that furazolidone was absorbed very quickly into blood and muscle with the time to reach maximum concentration (Tmax) at 2 h, with no significant differences in the apparent half-time of absorption phase (T1/2 A phase), half-time of distribution phase (T1/2 D/A phase), mean residens time (MRT), CL/F, and Vd(area), when the furazolidone dose was increased from 5 to 25 μ g/g body weight. But the half-time of elimination phase (T1/2 E phase) had significant differences at 25 μ g/g body weight than those of 5 μ g/g dosage in muscle. Furazolidone was absorbed comparatively slow into liver with the time to reach maximum concentration (Tmax) at 12 h, furazolidone at 5, 10, 25 μ g/g body weight were characterized with a rapid distribution phase and a relatively slow elimination phase, and the mean elimination half-life (T1/2E) was 166.19 ± 2.01, 169.82 ± 2.95, 173.90 ± 2.70 h at the dosage of at 5, 10, 25 μ g/g body weight in kidney, respectively, the residues of furzolidone ranged from 0.1–0.3 μ g/g at the dosage of at 5, 10, 25 μ g/g body weight after 360 h, furazolidone eliminated after 480 h in carassius aurats kidney. The areas under the plasma, muscle, liver and kidney concentration versus time curve from time 0 to 480 h (AUC0–480 h) were 50.43 ± 6.53 μ g h/g, 84.12 ± 5.61, 104.09 ± 4.82, and 109.16 ± 3.87 μ g h/g, significantly higher liver concentrations of AOZ were observed in carassius aurats than those kidney, muscle and plasma did. AOZ concentration was still 0.05 ± 0.01 μ g/g after 360 h. The predicted withdrawal time for carassius aurats was 480 h (20 days) at least.