Abstract
The pharmacokinetics of amoxicillin were studied in five Desert sheep and five Nubian goats after intravenous (i.v.) or intramuscular (i.m.) administration of a single dose of 10 mg/kg body weight. Following i.v. injection, the plasma concentration-versus-time data were best described by a two-compartment open model. The kinetic variables were similar in both species except for the volume of the central compartment (V-c), which was larger in sheep (p < 0.05). Following i.m. injection, except for the longer half-life time of absorption in goats (p < 0.05), there were no significant differences in other pharmacokinetic parameters between sheep and goats. The route of amoxicillin administration had no significant effect on the terminal elimination half-life in either species. The bioavailability of the drug (F) after i.m. administration was high (> 0.90) in both species. These results indicate that the pharmacokinetics of amoxicillin did not differ between sheep and goats; furthermore, because of the high availability and short half-life of absorption, the i.m. route gives similar results to the i.v. route. Therefore, identical intramuscular and intravenous dose regimens should be applicable to both species.