Biocompatibility and characteristics of theophylline/carboxymethyl chitosan microspheres for pulmonary drug delivery

The main aim was to evaluate the biocompatibility of theophylline/carboxymethyl chitosan/beta-cyclodextrin microspheres made by spray drying for pulmonary delivery. Haemolysis tests and cell culture experiments were used to determine blood and cell biocompatibility, and in vivo implantation experiments were used to examine tissue biocompatibility. The theophylline/carboxymethyl chitosan/beta-cyclodextrin microspheres were spherical in shape with a smooth or wrinkled surface, and showed no haemolysis activity. The cytotoxicity was dependent on concentration and showed no toxicity at low concentration. The results of implantation indicated that the inflammatory reaction gradually lessened and disappeared and had no significant difference from that of an operative suture. Therefore, theophylline/carboxymethyl chitosan/beta-cyclodextrin microspheres possess good biocompatibility and can be used as a promising carrier for pulmonary drug delivery. (c) 2013 Society of Chemical Industry