Buoyant sustained release granules based on chitosan.
Attempts to develop sustained release intragastric 'floating' granules based on chitosan are described, using chitosan of different degrees of deacetylation (chitosan H and L), in granular form or in laminated preparations. The granules were made from chitosan H (chitosan H granules), from a 1:1 mixture of chitosan H and L (1:1 mixture granules), from a 1:2 mixture of chitosan H and L (1:2 mixture granules), or from chitosan L (chitosan L granules). They were prepared by a method involving deacidification, had internal cavities, were immediately buoyant in both acidic and neutral fluids, and gave sustained release of prednisolone (used as a model drug). The laminated preparations, composed of a chitosan granule layer and a chitosan L membrane, were also immediately buoyant in the same fluids, and also provided sustained release of the model drug. The release properties were controlled by regulating the chitosan L content of the granules, or the chitosan L membrane thickness of the laminate. In an absorption study using beagle dogs, sustained drug absorption from these preparations was obtained.
Inouye
K
K
Faculty of Pharmaceutical Sciences, Hoshi University, Tokyo, Japan.
Machida
Y
Y
Sannan
T
T
Nagai
T
T
D000818:Animals; D002626:Chemistry, Pharmaceutical; D002686:Chitin / Q000031:analogs & derivatives* / Q000032:analysis; D048271:Chitosan; D003692:Delayed-Action Preparations; D004285:Dogs; D004339:Drug Compounding; D006863:Hydrogen-Ion Concentration; D007408:Intestinal Absorption; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011208:Powders; D011239:Prednisolone / Q000008:administration & dosage / Q000493:pharmacokinetics; D012995:Solubility
D003692:Delayed-Action Preparations; D011208:Powders; D002686:Chitin; D048271:Chitosan; D011239:Prednisolone