title: Development and in vitro evaluation of coated pellets containing chitosan to potential colonic drug delivery.
abstract: In this work pellets containing chitosan for colonic drug delivery were developed. The influence of the polysaccharide in the pellets was evaluated by swelling, drug dissolution and intestinal permeation studies. Drug-loaded pellets containing chitosan as swellable polymer were coated with an inner layer of Kollicoat(®) SR 30 D and an outer layer of the enteric polymer Kollicoat(®) MAE 30 DP in a fluidized-bed apparatus. Metronidazole released from pellets was assessed using Bio-Dis dissolution method. Swelling, drug release and intestinal permeation were dependent on the chitosan and the coating composition. The drug release data fitted well with the Weibull equation, indicating that the drug release was controlled by diffusion, polymer relaxation and erosion occurring simultaneously. The film coating was found to be the main factor controlling the drug release and the chitosan controlling the drug intestinal permeation. Coated pellets containing chitosan show great potential as a system for drug delivery to the colon.
authors.affiliation: Department of Drugs and Pharmaceuticals, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Araraquara, SP, Brazil.
authors.forename: Priscileila Colerato
authors.initials: PC
authors.lastname: Ferrari
authors.forename: Fagner Magalhães
authors.initials: FM
authors.lastname: Souza
authors.forename: Leandro
authors.initials: L
authors.lastname: Giorgetti
authors.forename: Giselle Faria
authors.initials: GF
authors.lastname: Oliveira
authors.forename: Humberto Gomes
authors.initials: HG
authors.lastname: Ferraz
authors.forename: Marco Vinícius
authors.initials: MV
authors.lastname: Chaud
authors.forename: Raul Cesar
authors.initials: RC
authors.lastname: Evangelista
mesh_terms: D000818:Animals; D048271:Chitosan / Q000737:chemistry*; D003106:Colon / Q000378:metabolism*; D004337:Drug Carriers / Q000737:chemistry*; D007408:Intestinal Absorption; D007700:Kinetics; D008297:Male; D008795:Metronidazole / Q000737:chemistry / Q000378:metabolism; D010539:Permeability; D011145:Polyvinyls / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004337:Drug Carriers; D011145:Polyvinyls; D008795:Metronidazole; C013215:polyvinyl acetate; D048271:Chitosan