title: Mechanism of drug release from silica-gelatin aerogel-Relationship between matrix structure and release kinetics.
abstract: Specific features of a silica-gelatin aerogel (3 wt.% gelatin content) in relation to drug delivery has been studied. It was confirmed that the release of both ibuprofen (IBU) and ketoprofen (KET) is about tenfold faster from loaded silica-gelatin aerogel than from pure silica aerogel, although the two matrices are structurally very similar. The main goal of the study was to understand the mechanistic background of the striking difference between the delivery properties of these closely related porous materials. Hydrated and dispersed silica-gelatin aerogel has been characterized by NMR cryoporometry, diffusiometry and relaxometry. The pore structure of the silica aerogel remains intact when it disintegrates in water. In contrast, dispersed silica-gelatin aerogel develops a strong hydration sphere, which reshapes the pore walls and deforms the pore structure. The drug release kinetics was studied on a few minutes time scale with 1s time resolution. Simultaneous evaluation of all relevant kinetic and structural information confirmed that strong hydration of the silica-gelatin skeleton facilitates the rapid desorption and dissolution of the drugs from the loaded aerogel. Such a driving force is not operative in pure silica aerogels.
authors.affiliation: Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, H-4032, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Veres
authors.affiliation: Department of Physical Chemistry, University of Debrecen, Egyetem tér 1, H-4032, Hungary.
authors.forename: Mónika
authors.initials: M
authors.lastname: Kéri
authors.affiliation: Department of Physical Chemistry, University of Debrecen, Egyetem tér 1, H-4032, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Bányai
authors.affiliation: Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, H-4032, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Lázár
authors.affiliation: Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, H-4032, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Fábián
authors.affiliation: Institut de Ciència de Materials de Barcelona (CSIC), Campus de la UAB, 08193 Bellaterra, Spain.
authors.forename: Concepción
authors.initials: C
authors.lastname: Domingo
authors.affiliation: MTA-DE Homogeneous Catalysis and Reaction Mechanisms Research Group, Egyetem tér 1, H-4032, Hungary. Electronic address: kalmar.jozsef@science.unideb.hu.
authors.forename: József
authors.initials: J
authors.lastname: Kalmár
mesh_terms: D004337:Drug Carriers / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D012822:Silicon Dioxide; D005780:Gelatin
keywords: Aerogel structure; Drug release; Kinetics; NMR spectroscopy