title: Effect of formulation parameters on the drug release and floating properties of gastric floating two-layer tablets with acetylsalicylic acid.
abstract: Floating dosage forms of acetylsalicylic acid, used for its antithrombotic effect, were developed to prolong gastric residence time and increase bioavailability. In the two-layer tablet formulation, hydroxypropyl methylcellulose (HPMC) of high viscosity and an effervescent mixture of citric acid and sodium bicarbonate formed the floating layer. The release layer contained the drug, direct tableting agent and different types of matrix-forming polymers such as HPMC of low viscosity, sodium carboxymethylcellulose and chitosan. Tablets were prepared using a direct compression technique. The effect of formulation variables on physicochemical and floating properties and the drug release from tablets were investigated. Floating ability was dependent on the amount of effervescent agent and gel-forming polymer of the floating layer. Drug release was prolonged to 8 hours by changing the type and viscosity of the matrix-forming polymer in the drug-loading layer and all formulations showed a diffusion release mechanisms.
authors.affiliation: Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Technology 06100-Tandogan, Ankara, Turkey.
authors.forename: Canan
authors.initials: C
authors.lastname: Hasçiçek
authors.forename: Günseli
authors.initials: G
authors.lastname: Yüksel-Tilkan
authors.forename: Berna
authors.initials: B
authors.lastname: Türkmen
authors.forename: Nurten
authors.initials: N
authors.lastname: Ozdemir
mesh_terms: D001241:Aspirin / Q000737:chemistry* / Q000378:metabolism; D001682:Biological Availability; D048271:Chitosan / Q000737:chemistry; D019343:Citric Acid / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000737:chemistry / Q000378:metabolism; D004339:Drug Compounding / Q000379:methods*; D016503:Drug Delivery Systems; D005079:Excipients / Q000737:chemistry*; D005343:Fibrinolytic Agents / Q000737:chemistry* / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D065347:Hypromellose Derivatives; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000737:chemistry; D008962:Models, Theoretical; D011108:Polymers / Q000737:chemistry; D011312:Pressure; D017693:Sodium Bicarbonate / Q000737:chemistry; D012995:Solubility; D013270:Stomach / Q000737:chemistry; D013607:Tablets / Q000737:chemistry; D013997:Time Factors; D014783:Viscosity
chemical_list: D003692:Delayed-Action Preparations; D005079:Excipients; D005343:Fibrinolytic Agents; D011108:Polymers; D013607:Tablets; D019343:Citric Acid; D065347:Hypromellose Derivatives; D017693:Sodium Bicarbonate; D008747:Methylcellulose; D048271:Chitosan; D001241:Aspirin