title: Polysaccharide-based aerogel microspheres for oral drug delivery.
abstract: Polysaccharide-based aerogels in the form of microspheres were investigated as carriers of poorly water soluble drugs for oral administration. These bio-based carriers may combine the biocompatibility of polysaccharides and the enhanced drug loading capacity of dry aerogels. Aerogel microspheres from starch, pectin and alginate were loaded with ketoprofen (anti-inflammatory drug) and benzoic acid (used in the management of urea cycle disorders) via supercritical CO2-assisted adsorption. Amount of drug loaded depended on the aerogel matrix structure and composition and reached values up to 1.0×10(-3) and 1.7×10(-3) g/m(2) for ketoprofen and benzoic acid in starch microspheres. After impregnation, drugs were in the amorphous state in the aerogel microspheres. Release behavior was evaluated in different pH media (pH 1.2 and 6.8). Controlled drug release from pectin and alginate aerogel microspheres fitted Gallagher-Corrigan release model (R(2)>0.99 in both cases), with different relative contribution of erosion and diffusion mechanisms depending on the matrix composition. Release from starch aerogel microspheres was driven by dissolution, fitting the first-order kinetics due to the rigid starch aerogel structure, and showed different release rate constant (k1) depending on the drug (0.075 and 0.160 min(-1) for ketoprofen and benzoic acid, respectively). Overall, the results point out the possibilities of tuning drug loading and release by carefully choosing the polysaccharide used to prepare the aerogels.
authors.affiliation: Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain; Institute of Thermal Separation Processes, Hamburg University of Technology, Eißendorferstraße 38, D-21073 Hamburg, Germany. Electronic address: carlos.garcia@usc.es.
authors.forename: C A
authors.initials: CA
authors.lastname: García-González
authors.affiliation: Institute of Thermal Separation Processes, Hamburg University of Technology, Eißendorferstraße 38, D-21073 Hamburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Jin
authors.affiliation: Institute of Environmental Technology and Energy Economics, Hamburg University of Technology, Eißendorferstraße 40, D-21073 Hamburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Gerth
authors.affiliation: Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Alvarez-Lorenzo
authors.affiliation: Institute of Thermal Separation Processes, Hamburg University of Technology, Eißendorferstraße 38, D-21073 Hamburg, Germany. Electronic address: irina.smirnova@tuhh.de.
authors.forename: I
authors.initials: I
authors.lastname: Smirnova
mesh_terms: D000284:Administration, Oral; D019817:Benzoic Acid / Q000008:administration & dosage / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry*; D065546:Drug Liberation; D005782:Gels; D006863:Hydrogen-Ion Concentration; D007660:Ketoprofen / Q000008:administration & dosage / Q000737:chemistry; D007700:Kinetics; D008863:Microspheres; D011134:Polysaccharides / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D004337:Drug Carriers; D005782:Gels; D011134:Polysaccharides; D014867:Water; D019817:Benzoic Acid; D007660:Ketoprofen
keywords: Benzoic acid; Drug release kinetics; Ketoprofen; Polysaccharide-based aerogel; Supercritical impregnation