Abioequivalence study on two closantel oral suspensions in sheep: an Iranian product (fascinil®) versus flukiver® as a reference product

BACKGROUND: Closantel is a broad-spectrum antiparasiticagent and is widely used for the control of Fasciola spp. andHaemonchus spp. infestations in sheep and cattle. OBJECTIVES:The present study was carried out to evaluate the bioequivalenceof a domestic closantel formulation, Fascinil® (DamloranPharmaceutical Co., Iran), in comparison with Flukiver®(Janssen pharmaceutical Co., Belgium) in sheep. METHODS: Ina parallel design, twenty-eight male sheep, 4- 5 months of age,were randomly divided into two groups. First group received asingle dose of Fascinil® oral suspension as a test product at 10mg/kg BW, and the second group received Flukiver® as areference product with the same dose. Blood samples were takenon 0, 4, 8, 12, 16, 20, 24, 32, 48, and 72 hours after drugadministration, and the plasma concentrations of closantel weredetermined using a high performance liquid chromatographic(HPLC) method. Pharmacokinetic analysis was performed; inaddition, the areas under the plasma concentration-time curvesat 0-72h (AUC0-72), maximum plasma concentrations (Cmax),and times to reach Cmax (Tmax) of the closantel in test andreference groups were compared. RESULTS: There were nosignificant differences in the AUC0-72 (2913.00±648.18,2957.88± 623.41 μg.h/mL), Cmax (62.22±7.74, 71.71±13.03μg/mL), and Tmax (23.38±4.27, 23.23±4.28h) between Fascinil®and Flukiver®, respectively. The 90% confidence intervals fortest: reference ratios of these pharmacokinetic (PK) parameterswere within bioequivalence acceptable range (80-120%).CONCLUSIONS: It is concluded that the test product (Fascinil®)and Flukiver® are bioequivalent, and they can be used asinterchangeable anthelmintic drugs.