title: Dissolution rate enhancement by adsorption of poorly soluble drugs on hydrophilic silica aerogels.
abstract: The aim of this work is to evaluate the feasibility of hydrophilic silica aerogels as drug carriers and to investigate the influence of the aerogels properties on the release rate of poorly water-soluble drugs. Hydrophilic silica aerogels of different densities were loaded with two model drugs, ketoprofen and griseofulvin, by adsorption from their solution in supercritical CO2. It is demonstrated that up to 30 wt% of ketoprofen and 5.4 wt% of griseofulvin can be deposited on hydrophilic aerogels through physical adsorption. The obtained drug-aerogel formulations were characterized by IR- and UV-spectroscopy, X-ray diffraction and scanning electron microscopy. Release kinetics of both drugs were studied in vitro. The release rate of ketoprofen from the drug-aerogel formulation is much faster than that of the corresponding crystalline drugs. The release rate of ketoprofen increases in 500% and that of griseofulvin in 450%, respectively. The reasons for the release enhancement are the enlarged specific surface area of drugs by adsorption on aerogels compared to their crystalline form and the immediate collapse of aerogel network in aqueous media. The dissolution rate of poorly water soluble drugs can be significantly enhanced by adsorption on highly porous hydrophilic silica aerogels.
authors.affiliation: Fachgebiet Thermodynamik und Thermische Verfahrenstechnik, Institut für Verfahrenstechnik, Technische Universität Berlin, Berlin, Germany. I.Smirnova@vt.tu-berlin.de
authors.forename: Irina
authors.initials: I
authors.lastname: Smirnova
authors.forename: Supakij
authors.initials: S
authors.lastname: Suttiruengwong
authors.forename: Matthias
authors.initials: M
authors.lastname: Seiler
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Arlt
mesh_terms: D000327:Adsorption / Q000187:drug effects*; D002245:Carbon Dioxide / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods; D025924:Chromatography, Supercritical Fluid / Q000379:methods; D003460:Crystallization; D004337:Drug Carriers / Q000737:chemistry / Q000493:pharmacokinetics; D004339:Drug Compounding / Q000379:methods; D016503:Drug Delivery Systems / Q000379:methods; D004355:Drug Stability; D005782:Gels / Q000737:chemistry / Q000493:pharmacokinetics*; D006118:Griseofulvin / Q000737:chemistry / Q000493:pharmacokinetics; D007660:Ketoprofen / Q000737:chemistry / Q000493:pharmacokinetics; D010316:Particle Size; D019999:Pharmaceutical Solutions; D011208:Powders; D012822:Silicon Dioxide / Q000737:chemistry / Q000493:pharmacokinetics*; D012995:Solubility / Q000187:drug effects*; D013816:Thermodynamics; D013997:Time Factors; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D004337:Drug Carriers; D005782:Gels; D019999:Pharmaceutical Solutions; D011208:Powders; D002245:Carbon Dioxide; D006118:Griseofulvin; D012822:Silicon Dioxide; D007660:Ketoprofen