Abstract

Trimethylchlorosilane silylated silica aerogel (TS-SA) was loaded with a model drug, aspirin. TS-SA preparation, drug loading, and drying were performed through ambient pressure techniques in a safe and cheap manner. The sample structure, drug loading, and drug dissolution profiles were characterized by N₂ adsorption and desorption analysis, FT-IR spectroscopy, UV absorption spectroscopy, FE-EM, EDX, XRD, and DSC. The characterization results indicated drug molecules are successfully loaded on the entire nanostructure of TS-SA. Specific surface area, total pore volume, and average pore size decrease with drug loading in TS-SA structure, as well as XRD and DSC results are indicating the amorphous state of loaded aspirin. Drug adsorption isotherm was measured and fitted well by the Freundlich model. Drug release kinetics from the samples were also evaluated in 0.1 N HCl (pH 1.2) and phosphate buffer (pH 7.4). The zero-order model, the first-order model, and the Higuchi model were employed to study the release kinetics. Better fitting to the Higuchi model showed that Fick's diffusion governs the aspirin release mechanism. The release rate of loaded samples was slower than the pure drug in both HCl and phosphate buffer. As pure aspirin dissolves totally in 0.1 N HCl and phosphate buffer within 40 min and 20 min, respectively, loaded drug dissolve 35% ± 4 and 80% ± 4 in 0.1 N HCl and phosphate buffer within 100 min. The ambient pressure drug loading on TS-SA could have interesting potential applications in controlled release drug delivery systems.

摘要

三甲基氯硅烷硅烷化二氧化硅气凝胶 (TS-SA) 装载了模型药物阿司匹林。TS-SA 制备、载药和干燥通过环境压力技术以安全且廉价的方式进行。样品结构、载药量和药物溶出曲线用 N _2表征吸附和解吸分析、FT-IR 光谱、UV 吸收光谱、FE-EM、EDX、XRD 和 DSC。表征结果表明药物分子成功地负载在TS-SA的整个纳米结构上。比表面积、总孔容和平均孔径随 TS-SA 结构中的药物负载而减小，以及 XRD 和 DSC 结果表明负载的阿司匹林处于无定形状态。通过 Freundlich 模型测量和拟合药物吸附等温线。还在 0.1 N HCl (pH 1.2) 和磷酸盐缓冲液 (pH 7.4) 中评估了样品的药物释放动力学。采用零级模型、一级模型和 Higuchi 模型来研究释放动力学。更好地拟合 Higuchi 模型表明 Fick 的扩散控制阿司匹林的释放机制。在 HCl 和磷酸盐缓冲液中，上样样品的释放速率都比纯药物慢。由于纯阿司匹林分别在 40 分钟和 20 分钟内完全溶解在 0.1 N HCl 和磷酸盐缓冲液中，加载的药物在 0.1 N HCl 和磷酸盐缓冲液中分别在 100 分钟内溶解 35% ± 4 和 80% ± 4。TS-SA 上的环境压力载药可能在控释药物递送系统中具有有趣的潜在应用。