title: Characterization of laminar extrudates manufactured at room temperature in the absence of solvents for the delivery of drugs.
abstract: Extrudates with laminar shape for delivery of drugs were manufactured at room temperature and without solvents. Different lipidic materials, formulations and extrusion conditions were studied, as well as the influence of the size of particles of coumarin on the release from the extrudates. Materials were mixed prior to feeding an in-house built ram extruder with a rectangular shaped die. The process of extrusion was characterized for the force at steady state whereas extrudates were characterized immediately after production and over storage for density, porosity, bending strength, elasticity, stiffness, deformation, thermal behavior and release performance of coumarin, the model drug. The variety of lipid excipients and their proportions in the formulations directly influenced the properties of the extrudates, namely the bending strength, stiffness, deformation and elasticity and, the density and porosity, which changed over storage time: in general, the bending strength, stiffness and porosity increased over time, whereas deformation, elasticy and density decreased. The thermal analysis supported these observations as there was an increase in the enthalpies of fusion of the extrudates over time. The release of coumarin from the extrudates occured both by diffusion within the extrudates and by structural alterations of the extrudates and an increase of the coumarin particle size corresponded to a decrease of the release rate. The study has proved the ability to manufacture extrudates in a continuous fashion, with laminar shape using a green technology.
authors.affiliation: iMed.UL - Departamento de Farmácia Galénica e Tecnologia Farmacêutica, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, P-1649-003 Lisboa, Portugal.
authors.forename: G
authors.initials: G
authors.lastname: Oliveira
authors.forename: M A
authors.initials: MA
authors.lastname: Wahl
authors.forename: J F
authors.initials: JF
authors.lastname: Pinto
mesh_terms: D003374:Coumarins / Q000737:chemistry*; D004058:Diffusion; D004337:Drug Carriers; D004548:Elasticity; D005079:Excipients / Q000737:chemistry*; D007700:Kinetics; D008055:Lipids / Q000737:chemistry*; D010316:Particle Size; D016062:Porosity; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D013678:Technology, Pharmaceutical / Q000379:methods*; D013696:Temperature
chemical_list: D003374:Coumarins; D004337:Drug Carriers; D005079:Excipients; D008055:Lipids; D012997:Solvents; C030123:coumarin
keywords: Extrusion; Green technology; Laminar extrusion; Mechanical properties; Room-temperature extrusion; Solvent-free extrusion