Abstract
BackgroundOsteoarthritis (OA) is the most common joint disorder worldwide and one of the leading causes of disability in the elderly. We have investigated the novel sodium hyaluronate derivative chemically linked with diclofenac (DF), diclofenac etalhyaluronate (SI-613), which is a potentially safer and more effective treatment for OA knee pain. In this study, we evaluated the pharmacological effects of SI-613 in experimental arthritis models.MethodsWe compared the analgesic and anti-inflammatory effects of intra-articularly administered SI-613, hyaluronic acid (HA), and of orally administered diclofenac sodium (DF-Na) in rat silver nitrate-induced arthritis model and rabbit antigen-induced arthritis model.ResultsA single intra-articular (IA) administration of SI-613 significantly suppressed pain responses in rats in a dose-dependent manner. The analgesic effects were greater than those of HA, a mixture of DF-Na and HA, or an oral once-daily administration of DF-Na. In the rabbit arthritis model, SI-613 significantly reduced knee joint swelling compared with that in the control group on day 1 after a single IA injection. This significant anti-inflammatory effect was observed until day 28. In the pharmacokinetic study, the DF concentration in the synovium after SI-613 administration reached its maximum concentration of 311.6 ng/g on day 1, and gradually declined to 10 ng/g by day 28. It fell below the lower limit of quantification on day 35. Thus, a clear correlation was found between pharmacokinetics and pharmacodynamics. These results demonstrate that SI-613 exerts its long-lasting and potent anti-inflammatory effect by sustainable release of DF in the knee joint tissues.ConclusionA single IA injection of SI-613 was shown to exert analgesic and anti-inflammatory effects for 28 days in non-clinical pharmacological studies, suggesting that SI-613 will be a promising candidate in the treatment of osteoarthritis pain.
Highlights
Osteoarthritis (OA) is the most common joint disorder worldwide and one of the leading causes of disability in the elderly
A single IA injection of SI-613 was shown to exert analgesic and anti-inflammatory effects for 28 days in non-clinical pharmacological studies, suggesting that SI-613 will be a promising candidate in the treatment of osteoarthritis pain
It is concluded that a single IA administration of SI-613 exerts a more efficacious and longer-lasting analgesic effect for arthritic pain than that exerted by individual chemical compositions
Summary
Osteoarthritis (OA) is the most common joint disorder worldwide and one of the leading causes of disability in the elderly. We have investigated the novel sodium hyaluronate derivative chemically linked with diclofenac (DF), diclofenac etalhyaluronate (SI-613), which is a potentially safer and more effective treatment for OA knee pain. The mainstay of pharmacological therapy for OA includes acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs) (oral and topical), cyclooxygenase-2 (COX-2) inhibitors, and IA therapies such as intra-articular sodium hyaluronate (IA-HA) injections and intra-articular-steroid (IA-steroid) injections. Oral NSAIDs including diclofenac sodium (DF-Na) were reported to have the same concerns as COX-2 inhibitors [4, 5]. Topical NSAIDs formulations, such as diclofenac sodium 1% gel, have equivalent efficacy and fewer adverse events compared with oral NSAIDs [6,7,8]. The intra-articular (IA) injection of hyaluronic acid (HA) is a recognized treatment for pain associated with symptomatic knee OA [9,10,11]. The efficacy of IA-HA injections is moderate compared to that of IA-steroids or oral
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
