Bioavailability and Tolerability of Topical and Oral Diclofenac Sodium Administration in Healthy Ponies

Aiming to characterize the bioavailability and assess the safety of topical and oral treatment of diclofenac sodium in healthy ponies, 18 animals were divided in three groups: one treated with topical (group I, n = 6), the second with oral diclofenac (group II, n = 6) at 2.5 mg/kg for 3 days, and the third group received 2.2 mg/kg oral phenylbutazone (group III, n = 6) also for 3 days to serve as positive control. To evaluate bioavailability, blood samples were collected before and at 0, 0.5, 1, 3, 6, 9, 12, 24, 36, 48, 60, 72, 96, 120, and 144 hours after starting treatment. To evaluate diclofenac sodium concentration in the synovial fluid, samples of six ponies (group I, n = 3; group II, n = 3) were collected at 6, 12, and 24 hours after starting the treatment.