title: Evaluation of SiO2 sonogels, prepared by a new catalyst-free method, as drug delivery system.
abstract: Recently, we reported on the synthesis of catalyst-free SiO(2) sonogels prepared by the sonication of a neutral distilled water/ tetraethyl ortosilicate mixture. The purpose of the present study was to evaluate the feasibility of using these sonogels as pharmaceutical delivery systems. A certified color additive (sunset yellow, SY) was used as a model compound for the release experiments. Different amounts of dye were incorporated into the gels before drying. Sonogels were characterized by scanning electron microscopy and differential scanning calorimetry. The effect of three drying temperatures (25 degrees C, 40 degrees C and 80 degrees C) and two mean grain sizes (1125 and 630 microm) on release behavior was analyzed. The analysis of variance showed no significant differences between the Higuchi's constants (K(H)) obtained for SY-loaded sonogels dried at 80 degrees C with different SY loads, irrespective of the mean grain size. In contrast, for SY-loaded sonogels dried at 40 degrees C, differences were found between sonogels loaded with 2.7, 7.7, 12.2, and 18.2% of SY, and no significant differences were detected between the mean grain sizes analyzed. Considering that the preparation of sonogels by the catalyst-free method allows an easy encapsulation, sonogels may offer an interesting alternative for drug release in the pharmaceutical field.
authors.affiliation: División de Estudios de Posgrado (Tecnología Farmacéutica), Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Estado de México, México.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Piñón-Segundo
authors.forename: Adriana
authors.initials: A
authors.lastname: Ganem-Quintanar
authors.forename: José Ocotlán
authors.initials: JO
authors.lastname: Flores-Flores
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Saniger-Blesa
authors.forename: María Zaida
authors.initials: MZ
authors.lastname: Urbán-Morlán
authors.forename: Luis
authors.initials: L
authors.lastname: Mendoza-Romero
authors.forename: María Guadalupe
authors.initials: MG
authors.lastname: Nava-Arzaluz
authors.forename: David
authors.initials: D
authors.lastname: Quintanar-Guerrero
mesh_terms: D002152:Calorimetry, Differential Scanning; D002214:Capsules; D002384:Catalysis; D004339:Drug Compounding; D016503:Drug Delivery Systems; D005782:Gels; D008855:Microscopy, Electron, Scanning; D012822:Silicon Dioxide / Q000737:chemistry*; D013696:Temperature
chemical_list: D002214:Capsules; D005782:Gels; D012822:Silicon Dioxide