title: Buoyant sustained release tablets based on chitosan.
abstract: This study attempted to develop sustained release intragastric 'floating' tablets based on chitosan. Two kinds of chitosan with different degrees of deacetylation (chitosan H and L) were used, and two types of preparations (types A and B) were examined. Type A preparations, i.e. directly compressed tablets using a mixture of sodium hydrogen carbonate and citric acid, were buoyant immediately and gave sustained release of prednisolone (as model drug) in acidic dissolution fluid. Type B preparations, i.e. preparations composed of a directly compressed layer and a chitosan H membrane layer enclosing carbon dioxide (a foamy membrane layer), quickly developed buoyancy and also provided sustained release of drug. The drug release rate from the preparation using chitosan L was slower than that from the preparation using chitosan H. In an absorption study using beagle dogs, sustained drug absorption from Type B preparations was obtained.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hoshi University, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Inouye
authors.forename: Y
authors.initials: Y
authors.lastname: Machida
authors.forename: T
authors.initials: T
authors.lastname: Sannan
authors.forename: T
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000818:Animals; D001639:Bicarbonates; D002614:Chelating Agents; D002686:Chitin / Q000031:analogs & derivatives*; D048271:Chitosan; D002951:Citrates; D019343:Citric Acid; D004285:Dogs; D015195:Drug Design; D008297:Male; D011239:Prednisolone / Q000097:blood*; D012964:Sodium; D017693:Sodium Bicarbonate; D012995:Solubility; D013608:Tablets, Enteric-Coated
chemical_list: D001639:Bicarbonates; D002614:Chelating Agents; D002951:Citrates; D013608:Tablets, Enteric-Coated; D002686:Chitin; D019343:Citric Acid; D017693:Sodium Bicarbonate; D048271:Chitosan; D012964:Sodium; D011239:Prednisolone