Plasma and synovial fluid concentrations of calcium pentosan polysulphate achieved in the horse following intramuscular injection.
Authors: Fuller C J, Ghosh P, Barr A R S
Journal: Equine veterinary journal
Summary
# Calcium Pentosan Polysulphate in Equine Joints: Establishing Therapeutic Dosing Calcium pentosan polysulphate (CaPPS) has shown promise in laboratory studies for managing osteoarthritis through modulation of cartilage metabolism, yet clinical application in horses remained unvalidated without established pharmacokinetic data. Fuller and colleagues administered a single 2 mg/kg intramuscular injection to six healthy horses and measured drug concentrations in both plasma and synovial fluid to determine whether therapeutic levels could be achieved in target joints. The synovial fluid concentrations obtained exceeded thresholds previously demonstrated in vitro to influence synoviocyte function, stimulate proteoglycan synthesis, and suppress matrix metalloproteinase activity—the cellular mechanisms implicated in cartilage degradation during osteoarthritis. These findings provide critical pharmacological justification for proceeding to clinical trials evaluating CaPPS efficacy in naturally occurring equine joint disease. For practitioners considering CaPPS as an intra-articular therapeutic, this foundational work confirms that intramuscular dosing achieves meaningful intra-articular drug exposure, though subsequent research would be needed to establish optimal dosing schedules, clinical efficacy, and practical application protocols.
Read the full abstract on PubMed
Practical Takeaways
- •CaPPS at 2 mg/kg i.m. achieves therapeutic concentrations in joint synovial fluid, supporting further investigation of this drug for treating equine osteoarthritis
- •This pharmacokinetic data provides justification for clinical efficacy trials, which are currently lacking in the equine literature
- •The relationship between plasma and synovial fluid drug concentrations has been established, enabling evidence-based dosing protocols for future therapeutic studies
Key Findings
- •A single 2 mg/kg intramuscular injection of calcium pentosan polysulphate achieved measurable concentrations in synovial fluid of target joints in healthy horses
- •Synovial fluid concentrations were sufficient to potentially elicit therapeutic effects on synoviocyte metabolism based on published in vitro studies
- •Drug concentrations may be adequate to stimulate proteoglycan synthesis and reduce matrix metalloproteinase activities in articular cartilage