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Research article - Peer-reviewed, 2022

In vivo joint synovial fluid disposition of a novel sustained-release formulation of diclofenac and hyaluronic acid in horses

Rhodin, Marie; Andersen, Pia Haubro; Forsstrom, Karin Holm; Ekstrand, Carl

Abstract

Intra-articular administration of sustained-release anti-inflammatory drugs is indicated in horses suffering from joint inflammation, but no such drugs are labelled for veterinary use. To obtain initial data on synovial disposition and safety of a new sustained-release formulation of diclofenac (SYN321) in the joints of horses, an experimental interventional study of elimination and side effects of intra-articular administration of SYN321 was conducted. Nine clinically sound horses were included in the study, and SYN321 was administered by the intra-articular route. Dose ranges and sampling intervals were established in a pilot study with two horses, and then applied in a main study involving seven horses treated in the fetlock joint. Diclofenac was detected above lower limit of quantification (LOQ: 0.5 ng/ml) in synovial fluid throughout the study period (14 days), and below LOQ (0.1 ng/ml) in plasma after 4 days and in urine after 14 days. No obvious clinical side effects were detected. Clinical examination and objective lameness evaluation suggested that SYN321 has potential as a local joint NSAID treatment with sustained release in horses, but further studies on synovial fluid exposure, safety and clinical efficacy are warranted.

Keywords

equine; intra-articular; NSAID; pharmacokinetics; slow-release

Published in

Journal of Veterinary Pharmacology and Therapeutics
2022, volume: 45, number: 2, pages: 167-176
Publisher: WILEY

Authors' information

Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry (AFB)
Swedish University of Agricultural Sciences, University Animal Hospital

UKÄ Subject classification

Clinical Science

Publication Identifiers

DOI: https://doi.org/10.1111/jvp.13033

URI (permanent link to this page)

https://res.slu.se/id/publ/114913