Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.
Molecules. 2009 Oct 30;14(11):4370-86. doi: 10.3390/molecules14114370.
Freeze-dried systems (L) comprising chitosan (CS) and caffeine (CAF) have been developed for oral administration. Different proportions of CS and CAF have been used in the preparation of the systems. Hot stage microscopy (HSM), differential scanning calorimetry (DSC) and X-ray diffraction powder have been used to characterize the systems prepared. X-ray diffraction patterns showed that there were no interactions between CAF and CS molecules within the freeze-dried systems and the crystallinity of CAF was decreased. Swelling and dissolution tests were carried out in two different media (demineralized water and pH progressive medium) in order to establish their influence over CAF/CS system behaviour. Characteristic swelling behaviour of freeze-dried CS systems (imbibition and dissolution processes) was influenced by the proportions of CS and CAF in the formulations, and by the nature of the medium due to the pH-dependent solubility of CS. Release of CAF from lyophilized systems was conditioned by the swelling process and it should be possible to obtain a CAF/CS binary system with a specific time for total drug release including concrete proportions of both components. Furthermore, the freeze-drying process allowed us to obtain feasible systems for controlled release of CAF until the total amount of drug was released.
已开发出用于口服的包含壳聚糖 (CS) 和咖啡因 (CAF) 的冷冻干燥系统 (L)。在制备系统时使用了不同比例的 CS 和 CAF。使用热台显微镜 (HSM)、差示扫描量热法 (DSC) 和 X 射线粉末衍射对制备的系统进行了表征。X 射线衍射图谱表明，冷冻干燥系统中 CAF 和 CS 分子之间没有相互作用，CAF 的结晶度降低。在两种不同的介质（去离子水和 pH 渐进介质）中进行了溶胀和溶解测试，以确定它们对 CAF/CS 系统行为的影响。冷冻干燥 CS 系统的特征溶胀行为（吸胀和溶解过程）受配方中 CS 和 CAF 比例以及介质性质的影响，这是由于 CS 的 pH 依赖性溶解度所致。CAF 从冻干系统中的释放受到溶胀过程的影响，应该有可能获得具有特定总药物释放时间的 CAF/CS 二元系统，包括两种成分的具体比例。此外，冷冻干燥过程允许我们获得可行的用于控制 CAF 释放的系统，直到释放完所有药物。
