Investigation of Plasma Concentrations Selamectin with Topical Administration in Sheep and Goats

In this study, plasma concentration with some kinetic parameters of selamectin, used for treatment of internal and external parasites in animals and a new derivate of avermectin, were investigated in 1 year old sheep and goats including 12 female akkaraman sheep and hair goats used in each. Both groups of animals were used selamectin (240 mg of 12 % Stronghold®, Pfizer) as a single topical dose of 12 mg/kg. Following administration of the drug during 35 days various intervals blood samples were taken and made necessary analysis. High pressure liquid chromatography (HPLC) were used for determination of plasma selamectin.At result of the analysis, plasma concentrations, maximum plasma concentration (Cmax), area under the curve (AUC), mean residence time (MRT) and the time to reach plasma maximum concentration (Tmax) of pharmacokinetic parameters were evaluated. Accordingly, plasma concentration of 1427.27 ± 90.52 pg/ml, Cmax 4.78 ± 0.61 ng/ml, AUC 810.35 ± 115.95 h.ng/ml, MRT 10.86 ± 0.89 days and Tmax 72 hours in sheeps; plasma concentration of 1195.03 ± 70.81 pg/ml, Cmax 3.27 ± 0.52 ng/ml, AUC 664.42 ± 72.62 h.ng/ml, MRT 10.46 ± 0.74 days and T max 72 hours were defined in goats. Despite there were observed significant differences in terms of plasma concentrations, Cmax and AUC values (p <0.05), there were no statistically differences in MRT and Tmax values statistically a significant diffence sheep and goats (p> 0.05).In conclusion, when selamectin were administrated by topical route treatment or control of parasitic infections in sheep and goats there were determined that plasma concentration, Cmax and AUC values in sheep higher than goat but there were not significant difference between MRT and Tmax values.Keywords: Selamectin, sheep, goat, topical administration, HPLC.