Abstract：
The release of the model drug theophylline from silica-pectin aerogels was investigated. The composite aerogels were prepared via impregnation of pectin alcogels with silica sol, followed by in situ silica gelation and drying with supercritical CO2. The structural and physico-chemical properties of the aerogels were tuned via the preparation conditions (type of silica sol, calcium crosslinking of pectin or not). Theophylline was loaded via impregnation and its release into simulated gastric fluid was studied during 1 h followed by release into simulated intestinal fluid. The swelling, mass loss and theophylline release behavior of the composites were analyzed and correlated with material properties. It followed that only aerogels prepared with calcium-crosslinked pectin and polyethoxydisiloxane were stable in aqueous systems, exhibiting a slow theophylline release governed by near-Fickian diffusion.
摘要：
研究了模型药物茶碱从二氧化硅-果胶气凝胶中的释放。通过用硅溶胶浸渍果胶醇凝胶制备复合气凝胶，然后原位二氧化硅凝胶化并用超临界CO2干燥。气凝胶的结构和物理化学性质通过制备条件（硅溶胶的类型，果胶的钙交联与否)。茶碱通过浸渍加载，并在1h内研究其释放到模拟胃液中，然后释放到模拟肠液中。肿胀，分析了复合材料的质量损失和茶碱释放行为，并与材料性能相关。因此，只有用钙交联果胶和聚乙氧基二硅氧烷制备的气凝胶在水性系统中稳定，表现出由近Fickian扩散控制的缓慢的茶碱释放。
