The addition of supercritical CO₂ to a polymeric solution allows to achieve an expanded liquid, characterized by reduced viscosity and surface tension. Thanks to this peculiarity, polyvinylpyrrolidone (PVP) microparticles and microfibers loaded with quercetin (QT) were produced, using a supercritical CO₂ assisted electrohydrodynamic process. The experiments were performed at different pressure, applied voltage, and polymer concentration; whereas, QT/PVP ratio was maintained constant at 3.5% w/w in all tested solutions. At 3% w/w PVP, particles with an average diameter of 0.77±0.24 μm were produced. At 15% w/w PVP, fibers were instead obtained, with an average diameter of 2.81±1.38 μm. The transition from electrospray to electrospinning occurred as a consequence of the polymer concentration that determined an increase in the solution viscosity. IR spectroscopy demonstrated the physical dispersion of QT into PVP fibers, and DSC showed that this drug was amorphous after processing. QT bioavailability was improved in the loaded fibers; it was released up to 30 times faster than from the unprocessed powder, and more than 90% of its native antioxidant activity was preserved.

将超临界CO _2添加到聚合物溶液中可实现膨胀的液体，其特征在于降低的粘度和表面张力。由于这种特殊性，使用超临界CO ₂制备了负载了槲皮素（QT）的聚乙烯吡咯烷酮（PVP）微粒和微纤维。辅助电动流体动力学过程。实验是在不同的压力，施加的电压和聚合物浓度下进行的。然而，在所有测试溶液中，QT / PVP比保持恒定在3.5％w / w。PVP为3％w / w时，平均粒径为0.77±0.24μm。在15％w / w PVP下，取而代之的是获得纤维，其平均直径为2.81±1.38μm。由于聚合物浓度决定了溶液粘度的增加，因此发生了从电喷雾到静电纺丝的转变。红外光谱证明了QT在PVP纤维中的物理分散，DSC表明该药物经过加工后是无定形的。负载纤维的QT生物利用度得到改善；它的释放速度比未经处理的粉末快30倍，