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Disposition of isoflupredone acetate in plasma, urine and synovial fluid following intra‐articular administration to exercised Thoroughbred horses
Author(s) -
Knych Heather K.,
Harrison Linda M.,
White Alexandria,
McKemie Daniel S.
Publication year - 2016
Publication title -
drug testing and analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.065
H-Index - 54
eISSN - 1942-7611
pISSN - 1942-7603
DOI - 10.1002/dta.1834
Subject(s) - horse , synovial fluid , pharmacokinetics , urine , intra articular , carpal joint , population , medicine , chemistry , pharmacology , osteoarthritis , surgery , pathology , biology , paleontology , alternative medicine , environmental health , wrist
The use of isoflupredone acetate in performance horses and the scarcity of published pharmacokinetic data necessitate further study. The objective of the current study was to describe the plasma pharmacokinetics of isoflupredone acetate as well as time‐related urine and synovial fluid concentrations following intra‐articular administration to horses. Twelve racing‐fit adult Thoroughbred horses received a single intra‐articular administration (8 mg) of isoflupredone acetate into the right antebrachiocarpal joint. Blood, urine and synovial fluid samples were collected prior to and at various times up to 28 days post drug administration. All samples were analyzed using liquid chromatography‐Mass Spectrometry. Plasma data were analyzed using a population pharmacokinetic compartmental model. Maximum measured plasma isoflupredone concentrations were 1.76 ± 0.526 ng/mL at 4.0 ± 1.31 h and 1.63 ± 0.243 ng/mL at 4.75 ± 0.5 h, respectively, for horses that had synovial fluid collected and for those that did not. The plasma beta half‐life was 24.2 h. Isoflupredone concentrations were below the limit of detection in all horses by 48 h and 7 days in plasma and urine, respectively. Isoflupredone was detected in the right antebrachiocarpal and middle carpal joints for 8.38 ± 5.21 and 2.38 ± 0.52 days, respectively. Results of this study provide information that can be used to regulate the use of intra‐articular isoflupredone in the horse. Copyright © 2015 John Wiley & Sons, Ltd.