title: In vitro and in vivo evaluation of mucoadhensiveness of chitosan/cellulose acetate multimicrospheres.
abstract: Chitosan/cellulose acetate multimicrospheres (CCAM) with or without ranitidine (RT) were prepared by the method of W/O/W emulsion with no toxic reagents and had the size interval of 200-280 microm. The angles of repose were only a little more than 30 degrees and the maximum angles of one-plane-critical-stability (OPCS phi) were about 20 degrees . The CCAM had good suspension ability for the tapped density of CCAM was less than 0.127g/mL. The pH value affected the swelling ability of CCAM and the relative humidity had little effect on the characteristics of CCAM when it was not more than 75%. The CCAM system had good effect on the controlled release of RT in vitro and the release rate was almost 60% during 48 h. Furthermore the release of RT was not affected by pH value of release medium. The mucoadhesive tests showed that CCAM could retain in gastrointestinal tract for an extended period of time. There were 53.7% of CCAM remained in stomach after administered for 2(1/2) h and 98.9% of CCAM remained in stomach and small intestine after administered for 3(1/2) h. These results suggest that CCAM is a useful dosage form targeting the gastric mucosa or prolonging gastric residence time as a multiple-unit mucoadhesive system.
authors.affiliation: College of Marine Life Science, Ocean University of China, Qingdao, People's Republic of China 266003.
authors.forename: Hui Yun
authors.initials: HY
authors.lastname: Zhou
authors.affiliation: College of Marine Life Science, Ocean University of China, Qingdao, People's Republic of China 266003.
authors.forename: Xi Guang
authors.initials: XG
authors.lastname: Chen
authors.affiliation: College of Marine Life Science, Ocean University of China, Qingdao, People's Republic of China 266003.
authors.forename: Wei Fen
authors.initials: WF
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002482:Cellulose / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D048271:Chitosan / Q000008:administration & dosage / Q000737:chemistry* / Q000494:pharmacology; D004337:Drug Carriers; D005772:Gastrointestinal Transit / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004337:Drug Carriers; C005062:acetylcellulose; D002482:Cellulose; D048271:Chitosan