Chitosan Temperature-Sensitive Gels: Reduce the Burst Release of Microspheres Containing Lornoxicam and Enhance Drug Targeting

Lornoxicam (Lnxc), a novel type of non-steroidal antiinflammatory drug developed by comely, was first listed in Denmark in October 1997 (trade name xefo). Clinically, it is used to treat rheumatoid, rheumatoid arthritis and osteoarthritis. The Lnxc with low drug concentration has a short half-life [1] after oral administration, leading to much side effect and therapy activity tended to be worse, therefore, the method of local injection of intra-articular cavity was concerned and widely used [2]. Intra-articular local administration of Lnxc is expected to be superior to systemic delivery in pain relieving and less adverse effects [3-5]. Intra-articular drug delivery system may be a better therapeutic approach for the treatment of a variety of knee pain. Through the animal study we can conclude that there were no side effects of intra-articular administration of Lnxc [6]. However, intra-articular injection is a kind of local treatment method, which can inject the drugs into the joint cavity of the patients directly. It is difficult to achieve continuous therapeutic effect after intraarticular injection, because a fast and almost complete absorption of Lornoxicam from the joints into the systemic circulation, so it often needs to be repeated several times [7].