Pharmacokinetics of a single dose of oclacitinib maleate as a top dress in adult horses.

The objective of this study was to determine the pharmacokinetic parameters of oclacitinib maleate as a top dress given to adult horses. Six adult horses with a mean weight of 528 kg were administered a single dose of 0.5 mg/kg oclacitinib maleate. Blood was collected prior to drug administration and at 15 min, 30 min, 45 min, 1, 2, 4, 6, 8, 12, 24, 48, and 72 hours after treatment. Oclacitinib maleate plasma concentrations were obtained via liquid chromatography mass spectrometry. Pharmacokinetic parameters were found best to fit a one-compartment model after using WinNonlin computer software analysis. Mean C_max was 486 ng/mL (range 423 – 549 ng/mL), and T_max was estimated to be 1.7 h (range 0.3 – 3.1h). The estimated T_1/2 was 7.5 h. Oclacitinib maleate is well absorbed following oral administration in the adult horse.