title: Compressed mini-tablets as a biphasic delivery system.
abstract: Compressed mini-tablets systems are presented as a biphasic delivery system designed for zero-order sustained drug release. The outer layer that fills the void spaces between the mini-tablets was formulated to release the drug in a very short time (fast release), while the mini-tablets provided a prolonged release. Different composition (HPMC or EC) and number (10 or 21) of mini-tablets were used to obtain different drug release rates. The in vitro performance of these systems showed the desired biphasic behaviour: the drug contained in the fast releasing phase (powder enrobing the mini-tablets) dissolved within the first 2 min, whereas the drug contained in the mini-tablets was released at different rates, depending up on formulation. Based on the release kinetic parameters calculated, it can be concluded that mini-tablets containing HPMC were particularly suitable approaching to zero-order (constant) release over 8h time periods.
authors.affiliation: Departamento de Tecnologia Farmacêutica, Faculdade de Farmácia, Universidade do Porto, Rua Aníbal Cunha 164, 4050-047 Porto, Portugal. clopes@ff.up.pt
authors.forename: Carla M
authors.initials: CM
authors.lastname: Lopes
authors.forename: José Manuel Sousa
authors.initials: JM
authors.lastname: Lobo
authors.forename: João F
authors.initials: JF
authors.lastname: Pinto
authors.forename: Paulo
authors.initials: P
authors.lastname: Costa
mesh_terms: D000465:Algorithms; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D004339:Drug Compounding / Q000379:methods; D016503:Drug Delivery Systems / Q000379:methods*; D005079:Excipients / Q000737:chemistry; D065347:Hypromellose Derivatives; D007052:Ibuprofen / Q000008:administration & dosage / Q000493:pharmacokinetics; D007700:Kinetics; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000737:chemistry; D008956:Models, Chemical; D016062:Porosity; D013607:Tablets / Q000737:chemistry*; D013718:Tensile Strength
chemical_list: D005079:Excipients; D013607:Tablets; D065347:Hypromellose Derivatives; C013517:ethyl cellulose; D002482:Cellulose; D008747:Methylcellulose; D002266:Carboxymethylcellulose Sodium; C109691:microcrystalline cellulose; D007052:Ibuprofen