Larrañeta Eneko, Martínez-Ohárriz Cristina, Vélaz Itziar, Zornoza Arantza, Machín Rubén, Isasi José Ramón
Departamento de Química y Edafología, Facultad de Ciencias, Universidad de Navarra, Pamplona, Navarra, 31080, Spain.
J Pharm Sci. 2014 Jan;103(1):197-206. doi: 10.1002/jps.23774. Epub 2013 Nov 8.
Gels obtained by complexation of octablock star polyethylene oxide/polypropylene oxide copolymers (Tetronic 90R4) with α-cyclodextrin (α-CD) were evaluated as matrices for drug release. Both molecules are biocompatible so they can be potentially applied to drug delivery systems. Two different types of matrices of Tetronic 90R4 and α-CD were evaluated: gels and tablets. These gels are capable to gelifying in situ and show sustained erosion kinetics in aqueous media. Tablets were prepared by freeze-drying and comprising the gels. Using these two different matrices, the release of two model molecules, L-tryptophan (Trp), and a protein, bovine serum albumin (BSA), was evaluated. The release profiles of these molecules from gels and tablets prove that they are suitable for sustained delivery. Mathematical models were applied to the release curves from tablets to elucidate the drug delivery mechanism. Good correlations were found for the fittings of the release curves to different equations. The results point that the release of Trp from different tablets is always governed by Fickian diffusion, whereas the release of BSA is governed by a combination of diffusion and tablet erosion.
通过八嵌段星形聚环氧乙烷/聚环氧丙烷共聚物（Tetronic 90R4）与α-环糊精（α-CD）络合得到的凝胶被评估为药物释放的基质。这两种分子都具有生物相容性，因此它们有可能应用于药物递送系统。评估了Tetronic 90R4和α-CD的两种不同类型的基质：凝胶和片剂。这些凝胶能够原位凝胶化，并在水性介质中显示出持续的侵蚀动力学。片剂通过冷冻干燥制备，并包含凝胶。使用这两种不同的基质，评估了两种模型分子L-色氨酸（Trp）和一种蛋白质牛血清白蛋白（BSA）的释放。这些分子从凝胶和片剂中的释放曲线证明它们适用于持续递送。将数学模型应用于片剂的释放曲线以阐明药物递送机制。发现释放曲线与不同方程的拟合具有良好的相关性。结果表明，不同片剂中Trp的释放始终受菲克扩散控制，而BSA的释放则受扩散和片剂侵蚀的共同控制。
