title: The applicability of ordered mesoporous SBA-15 and its hydrophobic glutaraldehyde-bridge derivative to improve ibuprofen-loading in releasing system.
abstract: The mesoporous SBA-15 silica with uniform hexagonal pore, narrow pore size distribution and tuneable pore diameter was organofunctionalized with glutaraldehyde-bridged silylating agent. The precursor and its derivative silicas were ibuprofen-loaded for controlled delivery in simulated biological fluids. The synthesized silicas were characterized by elemental analysis, infrared spectroscopy, (13)C and (29)Si solid state NMR spectroscopy, nitrogen adsorption, X-ray diffractometry, thermogravimetry and scanning electron microscopy. Surface functionalization with amine containing bridged hydrophobic structure resulted in significantly decreased surface area from 802.4 to 63.0 m(2) g(-1) and pore diameter 8.0-6.0 nm, which ultimately increased the drug-loading capacity from 18.0% up to 28.3% and a very slow release rate of ibuprofen over the period of 72.5h. The in vitro drug release demonstrated that SBA-15 presented the fastest release from 25% to 27% and SBA-15GA gave near 10% of drug release in all fluids during 72.5 h. The Korsmeyer-Peppas model better fits the release data with the Fickian diffusion mechanism and zero order kinetics for synthesized mesoporous silicas. Both pore sizes and hydrophobicity influenced the rate of the release process, indicating that the chemically modified silica can be suggested to design formulation of slow and constant release over a defined period, to avoid repeated administration.
authors.affiliation: Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP, Brazil.
authors.forename: Fozia
authors.initials: F
authors.lastname: Rehman
authors.affiliation: Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP, Brazil. Electronic address: volpe@iqm.unicamp.br.
authors.forename: Pedro L O
authors.initials: PL
authors.lastname: Volpe
authors.affiliation: Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP, Brazil.
authors.forename: Claudio
authors.initials: C
authors.lastname: Airoldi
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000138:chemical synthesis*; D004058:Diffusion; D004339:Drug Compounding; D005976:Glutaral / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007052:Ibuprofen / Q000737:chemistry*; D007700:Kinetics; D010316:Particle Size; D016062:Porosity; D011437:Propylamines; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D011437:Propylamines; C509969:SBA-15; D012821:Silanes; D012822:Silicon Dioxide; C477625:amino-propyl-triethoxysilane; D005976:Glutaral; D007052:Ibuprofen
keywords: Drug delivery; Glutaraldehyde; Ibuprofen; Mesoporous silica; Organofunctionalization