title: A novel floating controlled release drug delivery system prepared by hot-melt extrusion.
abstract: Floating dosage forms are an important formulation strategy for drugs with a narrow absorption window and low intestinal solubility, and for localized gastric treatment. Novel floating pellets were prepared using the hot-melt extrusion (HME) technology. Uniformly foamed strands were created by liquid injection pumping and screw configuration modification. The ammonio methacrylate copolymer (Eudragit® RSPO) foaming structure was formed by a liquid-vapor phase transition inside the strand upon die exiting resulting from the sudden decrease in external pressure, vaporizing the liquid ethanol and vacating the extruded material. This generated uniform vacuous regions in the extrudate. The pellets' internal structure was investigated using scanning electron microscopy (SEM). The formulation constituents' and processing parameters' effects on the drug release profiles, floating force, and the pellets' micromeritic properties were evaluated by design of experiments: all formulations showed zero lag time and excellent floating strength, indicating immediate-floating pellet formation. The pellets' drug release profiles were controlled by multiple independent variables at different time points (⩽ 24 h). Drug loading significantly affected drug release within the first hour, the hydroxypropyl methylcellulose (HPMC) content thereafter. Understanding the variables' effects on the formulations allows for the tailoring of this delivery system to obtain various drug release profiles.
authors.affiliation: Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University, MS 38677, USA.
authors.forename: Anh Q
authors.initials: AQ
authors.lastname: Vo
authors.affiliation: Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University, MS 38677, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Feng
authors.affiliation: Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University, MS 38677, USA.
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Morott
authors.affiliation: Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University, MS 38677, USA.
authors.forename: Manjeet B
authors.initials: MB
authors.lastname: Pimparade
authors.affiliation: Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University, MS 38677, USA.
authors.forename: Roshan V
authors.initials: RV
authors.lastname: Tiwari
authors.affiliation: College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Pharmaceutics and Drug Delivery, School of Pharmacy, The University of Mississippi, University, MS 38677, USA; Pii Center for Pharmaceutical Technology, The University of Mississippi, University, MS 38677, USA. Electronic address: marepka@olemiss.edu.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Repka
mesh_terms: D003692:Delayed-Action Preparations; D012995:Solubility; D013678:Technology, Pharmaceutical; D013696:Temperature; D013806:Theophylline / Q000008:administration & dosage / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D003692:Delayed-Action Preparations; D013806:Theophylline
keywords: Chemical imaging; Controlled release; Eudragit® RSPO; Floating drug delivery system; Foamed extrudate; Hot-melt extrusion; Theophylline