The use of supercritical fluids technology, in particular the use of CO2, is an important advantage over other production techniques of controlled release systems. The impregnation and foaming process can be carried out in a single step. By adjusting the conditions of pressure, temperature, depressurization time or type of polymer used, microcellular scaffolds can be obtained with desired characteristics and adapted to the patient's requirements. Moreover, it has been demonstrated that the use of polymeric solutions allows carrying out impregnation process at mild conditions. In this work, Gemcitabine impregnation in PLGA foams from polymeric solutions of ethyl lactate has been studied. The effect of polymer lactide to glycolide ratio (50:50 or 75:25), pressure (120 or 200 bar) and temperature (25 or 40 °C) were studied for three initial drug ratios (175, 105 or 35 mg GEM/g PLGA). Cell size of the foams varied between 35 μm and 158 μm, achieving an impregnation efficiency higher than 90 %. Finally, a study of the release profile of Gemcitabine in Phosphate Buffered Saline (PBS) was investigated and a mathematical modelling was carried out. In this model it was considered that the release process was divided into three different steps controlled by the external diffusion in the first place, by the internal transfer of mass in the second and then by the degradation of the polymer.

与其他控释系统生产技术相比，超临界流体技术的使用，尤其是二氧化碳的使用，具有重要的优势。浸渍和发泡过程可以在一个步骤中进行。通过调节压力，温度，减压时间或所用聚合物的类型，可以获得具有所需特性并适合患者需求的微细胞支架。此外，已经证明，使用聚合物溶液可以在温和的条件下进行浸渍过程。在这项工作中，已经研究了吉西他滨从乳酸乙酯的聚合溶液中浸入PLGA泡沫中的过程。聚合物丙交酯与乙交酯的比率（50:50或75:25）的影响，研究了三种初始药物配比（175、105或35 mg GEM / g PLGA）的最大压力（120或200 bar）和温度（25或40°C）。泡沫的泡孔尺寸在35μm至158μm之间变化，浸渍效率高于90％。最后，研究了吉西他滨在磷酸盐缓冲盐水（PBS）中的释放曲线，并进行了数学建模。在该模型中，认为释放过程分为三个不同的步骤，首先由外部扩散控制，然后由质量内部转移控制，然后由聚合物降解控制。研究了吉西他滨在磷酸盐缓冲盐水（PBS）中的释放曲线，并进行了数学建模。在该模型中，认为释放过程分为三个不同的步骤，首先由外部扩散控制，然后由质量内部转移控制，然后由聚合物降解控制。研究了吉西他滨在磷酸盐缓冲盐水（PBS）中的释放曲线，并进行了数学建模。在该模型中，认为释放过程分为三个不同的步骤，首先由外部扩散控制，然后由质量内部转移控制，然后由聚合物降解控制。