Abstract：
The in vitro permeation testing (IVPT) of topical products is performed across the human cadaver skin, which is stored frozen for a prolonged duration. The cryo-preservation technique is not economical and is a cumbersome process. Moreover, prolonged skin preservation in a frozen state and frequent freeze-thawing are known to affect the integrity of the skin barrier. Therefore, lyophilization was explored as an alternative to protect the skin tissue from microbial contamination and degeneration. Notably, the project\'s objective was to investigate the impact of the freeze-drying process on the skin\'s barrier properties. The morphometrics of the lyophilized skin were measured. Histological studies did not reveal any notable changes in the organization and intactness of the layers due to the freeze-drying process. The biophysical attributes of the skin, such as transepidermal water evaporation rate and transepidermal electrical resistivity (TEER), were not significantly different between the control skin (not subjected to the freeze-drying process) and the freeze-dried skin (FDS). The permeability of caffeine, a hydrophilic model permeant, and nicotine, a lipophilic model permeant, were consistent across the control and the FDS. It is evident from the studies that the lyophilization process did not significantly impact the barrier properties and permeability of the skin.
摘要：
局部产品的体外渗透测试（IVPT）是在人体尸体皮肤上进行的，它被冷冻保存很长时间。冷冻保存技术是不经济的并且是麻烦的过程。此外，已知在冷冻状态下长时间保存皮肤和频繁的冻融会影响皮肤屏障的完整性。因此,研究了冻干作为保护皮肤组织免受微生物污染和变性的替代方法。值得注意的是,该项目的目的是研究冷冻干燥过程对皮肤屏障性能的影响。测量冻干皮肤的形态计量学。组织学研究未发现由于冷冻干燥过程，层的组织和完整性发生了任何显着变化。皮肤的生物物理属性，如经表皮水分蒸发速率和经表皮电阻率(TEER)，在对照皮肤（未进行冷冻干燥过程）和冷冻干燥皮肤（FDS）之间没有显着差异。咖啡因的渗透性，亲水模型渗透物，还有尼古丁,亲脂性模型渗透物，在对照和FDS之间是一致的。从研究中可以明显看出,冻干过程没有显著影响皮肤的屏障性质和渗透性。
