Pharmacokinetics and physio‐metabolic response of single and multiple dose of fenbendazole inLabeo rohita(Hamilton, 1822) fingerlings

Abstract

An experiment was carried to determine the plasma fenbendazole (FBZ) concentration and physio-metabolic responses in juveniles of Labeo rohita (90 ± 4 g) after oral administration of single doses at 10, 20 and 50 mg, 20 mg FBZ/kg b.wt. in multiple times on 1st, 3rd and 7th day. The blood samples were collected at 0.5, 1, 2, 4, 8, 12, 24, 30, 48, 72, 96 and 120 hr, after single-dose administration, and regularly (upto 15 day) in multiple dose. Plasma FBZ concentration was determined up to the limit of detection (LoD) of 0.09 µg/ml by HPLC. There was no parent drug detected in plasma for administration of 10 mg FBZ/kg b.wt. The drug attained the peak concentration (Cmax) 1.85 and 3.09 µg/ml in plasma at 4 hr (Tmax) after administration of 20 and 50mg FBZ/kg b.wt. respectively. Plasma FBZ was detectable up to 96 and 120 hr with concentration 0.09 ± 0.007 and 0.098 ± 0.006 µg/ml, respectively, after single-dose administration of 20 and 50mg/kg b.wt. In case of multiple-dose administration, the maximum concentration of FBZ was 1.01 ± 0.03 µg/ml on 7th day that was less than to the single dose at 50 mg/kg b.wt. However, FBZ was detected up to 11 day after multiple doses. The study revealed that the hepatic antioxidant enzymes activities like superoxide dismutase, catalase and glutathione-S-transferase were significantly affected by increasing FBZ in single and multiple doses. The results of the present study could reveal that single- or multiple-oral administration of FBZ at 20 mg/kg b.wt. in feed as antihelminthic drug in L. rohita could be considered as the safe dose.