Comparison of pharmacokinetics of two tylvalosin oral formulations in broiler chickens.

The objective of the study was to compare the relative bioavailability and pharmacokinetics of two commercially available oral formulations of tylvalosin prepared for use in broiler chickens (ProviLosin R and AviLosin R ). A total of 36 healthy, broiler chickens were administered a single oral dose (25 mg/kg b.w.) of each formulation in a parallel randomized design. The relative bioavailability of ProviLosin R was 108% compared to AviLosin R . There were no significant differences between ProviLosin R and AviLosin R tylvalosin formulations in the average means of the area under the plasma concentration-time curve, maximum plasma concentrations and time to maximum plasma concentrations. In conclusion, tylvalosin was rapidly absorbed and relatively slowly eliminated after oral administration of a single dose for both formulations. ProviLosin R and AviLosin R can be used interchangeably as therapeutic agents in broiler chickens.