Celecoxib incorporated chitosan microspheres: in vitro and in vivo evaluation.

Recently, considerable interest has been focussed on the use of biodegradable polymers for specialized applications such as controlled release of drug formulations; meanwhile, microsphere drug delivery systems using various kinds of biodegradable polymers have been studied extensively during the past two decades. In the present investigation, it was aimed to prepare microsphere formulations of celecoxib using a natural polymer, chitosan as a carrier for intra-articular administration to extend the retention of the drug in the knee joint. Microsphere formulations were evaluated in vitro for particle size, entrapment efficiency, surface morphology and in vitro drug release. For in vivo studies, (99m)Technetium- labeled glutathione was used as a radiopharmaceutical to demonstrate arthritic lesions by gamma scintigraphy. Evaluation of arthritic lesions post therapy in rats showed a significant difference (P < 0.005) in the group treated with celecoxib solution compared to the group treated with celecoxib loaded chitosan microspheres.