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  • Pharmacokinetic disposition of triclabendazole in cattle and sheep; discrimination of the order and the rate of the absorption process of its active metabolite triclabendazole sulfoxide.

Pharmacokinetic disposition of triclabendazole in cattle and sheep; discrimination of the order and the rate of the absorption process of its active metabolite triclabendazole sulfoxide.

Veterinary research communications (2007-04-26)
N Mestorino, E A Formentini, M F Lucas, C Fernandez, P Modamio, E Mariño Hernández, J O Errecalde
ABSTRACT

A comparative pharmacokinetic study was conducted to determine the order and the rate of absorption of triclabendazole (TCBZ) in cattle and sheep. A commercial suspension of TCBZ (Biofasiolex, Biogénesis S.A., Argentina) was administered at a dose rate of 10 mg/kg by the oral route to six Holstein female calves and six Corriedale female sheep. The plasma concentration profiles of the metabolites triclabendazole sulfoxide (TCBZ-SO) and triclabendazole sulfone (TCBZ-SO(2)) were analysed by means of the non-compartmental method. The order of the absorption process of the active metabolite, TCBZ-SO, was determined by construction of curves of cumulative absorbed fraction of the drug by means of the Wagner-Nelson method. The appearance of TCBZ-SO in plasma of cattle and sheep resembles the entry of a constant quantity of drug into the organism per unit time. This is explained by the reservoir effect of the rumen, which acts as a biological slow-release system for TCBZ-SO and its precursor TCBZ to the posterior digestive tract where they are absorbed. The plasma concentration profiles of TCBZ-SO in both species were well described by a one-compartment open model with zero-order process of absorption and first-order process of elimination. The values of AUC(0-infinity) and C(max) of TCBZ-SO did not differ between species, while other kinetic parameters except for lambda(z) had higher values in calves than in sheep. In the case of TCBZ-SO(2), t(max) was the only parameter that did not differ between species, while other kinetic parameters except for lambda(z) had higher values in calves than in sheep.

MATERIALS
Product Number
Brand
Product Description

Supelco
Triclabendazole sulfoxide, VETRANAL®, analytical standard