title: Design and evaluation of chitosan/ethylcellulose mucoadhesive bilayered devices for buccal drug delivery.
abstract: This paper describes the preparation of new buccal bilayered devices comprising a drug-containing mucoadhesive layer and a drug-free backing layer, by two different methods. Bilaminated films were produced by a casting/solvent evaporation technique and bilayered tablets were obtained by direct compression. The mucoadhesive layer was composed of a mixture of drug and chitosan, with or without an anionic crosslinking polymer (polycarbophil, sodium alginate, gellan gum), and the backing layer was made of ethylcellulose. The double-layered structure design was expected to provide drug delivery in a unidirectional fashion to the mucosa and avoid loss of drug due to wash-out with saliva. Using nifedipine and propranolol hydrochloride as slightly and highly water-soluble model drugs, respectively, it was demonstrated that these new devices show promising potential for use in controlled delivery of drugs to the oral cavity. The uncrosslinked chitosan-containing devices absorbed a large quantity of water, gelled and then eroded, allowing drug release. The bilaminated films showed a sustained drug release in a phosphate buffer (pH 6.4). Furthermore, tablets that displayed controlled swelling and drug release and adequate adhesivity were produced by in situ crosslinking the chitosan with polycarbophil.
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, The University of Santiago de Compostela, Campus Sur, 15706-Santiago de Compostela, Spain. ffcarelo@usc.es
authors.forename: C
authors.initials: C
authors.lastname: Remuñán-López
authors.forename: A
authors.initials: A
authors.lastname: Portero
authors.forename: J L
authors.initials: JL
authors.lastname: Vila-Jato
authors.forename: M J
authors.initials: MJ
authors.lastname: Alonso
mesh_terms: D000269:Adhesives; D000818:Animals; D002417:Cattle; D002482:Cellulose / Q000031:analogs & derivatives*; D002610:Cheek; D002686:Chitin / Q000031:analogs & derivatives*; D048271:Chitosan; D016503:Drug Delivery Systems; D005069:Evaluation Studies as Topic; D008854:Microscopy, Electron; D009543:Nifedipine / Q000008:administration & dosage / Q000493:pharmacokinetics; D011433:Propranolol / Q000008:administration & dosage / Q000493:pharmacokinetics
chemical_list: D000269:Adhesives; D002686:Chitin; C013517:ethyl cellulose; D002482:Cellulose; D048271:Chitosan; D011433:Propranolol; D009543:Nifedipine