Progress in Intra-Articular Drug Delivery Systems for Osteoarthritis

As the most common form of arthritis, osteoarthritis (OA) is prevalent in the elderly, bringing patients pain and functional limitations of joints. Current medication treatments of OA mainly consist of oral and intra-articular administration. Despite the undeniable advantages over oral administration, the efficacy of intra-articular therapy is still limited by the rapid clearance of drugs. To guarantee the efficacy and avoid frequent injections, rationally designed intra-articular drug delivery systems (DDSs), which may remain in OA joints for a long time and sustainedly release drugs, are clinically in need. In this article, we present a review of the novel intra-articular DDSs for OA treatment reported recently, especially in the last five years. Factors influencing the biocompatibility and efficacy of such systems are also addressed. Moreover, the potential fate of different systems in joints is highlighted. Future innovations in this field may lie in the discovery of effective DMOADs and the development of novel biomaterials as carriers of bioactivity substances. Keywords: Depot formulation, drug delivery system, intra-articular administration, osteoarthritis (OA), targeted delivery.