Abstract: Floating-bioadhesive microcapsules containing clarithromycin were prepared by a combined method of emulsion solvent diffusion and internal/ion gelation for the treatment of Helicobacter pylori. Ethylcellulose microsphers(EMs) were prepared by the emulsion solvent diffusion method. EMs were coated with alginate and chitosan by the internal/ion gelation method to get alginate-ethylcellulose microcapsules(AEMs) and chitosan-alginate-ethylcellulose microcapsules(CAEMs). The drug efficiency and drug content of clarithromycin in CAEMs were determined to be 72.3%—78.2% and 7.1%—12.7%, respectively. CAEMs showed an obviously sustaining effect for more than 6h in vitro, and more than 70% of CAEMs floated in acetate buffer solution for 8 h in vitro. Furthermore, the in vitro remaining percentage of CAEMs in the stomach 4 h after the administration was 60.5%. The results suggest that floating-bioadhesive microcapsules might be a promising drug delivery system for the treatment of Helicobacter pylori infection.

Key words: Floating-bioadhesive microcapsules, In vitro floating characteristic, Gastric residence characteristic, Helicobacter pylori