BACKGROUND: Closantel is a broad-spectrum antiparasitic
agent and is widely used for the control of Fasciola spp. and
Haemonchus spp. infestations in sheep and cattle. OBJECTIVES:
The present study was carried out to evaluate the bioequivalence
of a domestic closantel formulation, Fascinil® (Damloran
Pharmaceutical Co., Iran), in comparison with Flukiver®
(Janssen pharmaceutical Co., Belgium) in sheep. METHODS: In
a parallel design, twenty-eight male sheep, 4- 5 months of age,
were randomly divided into two groups. First group received a
single dose of Fascinil® oral suspension as a test product at 10
mg/kg BW, and the second group received Flukiver® as a
reference product with the same dose. Blood samples were taken
on 0, 4, 8, 12, 16, 20, 24, 32, 48, and 72 hours after drug
administration, and the plasma concentrations of closantel were
determined using a high performance liquid chromatographic
(HPLC) method. Pharmacokinetic analysis was performed; in
addition, the areas under the plasma concentration-time curves
at 0-72h (AUC0-72), maximum plasma concentrations (Cmax),
and times to reach Cmax (Tmax) of the closantel in test and
reference groups were compared. RESULTS: There were no
significant 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 for
test: reference ratios of these pharmacokinetic (PK) parameters
were within bioequivalence acceptable range (80-120%).
CONCLUSIONS: It is concluded that the test product (Fascinil®)
and Flukiver® are bioequivalent, and they can be used as
interchangeable anthelmintic drugs.