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 h after treatment. Oclacitinib maleate plasma concentrations were measured by liquid chromatography/mass spectrometry. Pharmacokinetic parameters were found best to fit a one-compartment model. Mean C-max was 486 ng/ml (range 423-549 ng/ml), and T-max was estimated to be 1.7 h (range 0.3-3.1 h). The estimated T-1/2 was 7.5-8 h.