Sintov Amnon C
Department of Biomedical Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Be'er Sheva 84105, Israel.
Eur J Pharm Sci. 2017 May 1;102:261-263. doi: 10.1016/j.ejps.2017.03.024. Epub 2017 Mar 18.
Porcine skin has frequently been used as a model in in vitro permeation studies being considered as an excellent alternative for human skin due to biochemical similarities. The use of frozen skin after thawing is particularly more convenient for these studies since it is available whenever needed. Even though several researchers have noticed that freezing and then thawing the tissue result in enhancement of drug permeation, many published articles have still described studies using frozen pig skin for bioequivalence and transdermal evaluation of drug products. The aim of this commentary article is therefore to explicitly demonstrate, according to our experience, the low-reliability of the convenient protocol of freezing pig skin for in vitro percutaneous studies. It has been shown in three separate studies using three different drugs that frozen/thawed pig skin had a higher permeability to drugs compared to that obtained by using fresh skin. The results have further demonstrated that the abnormal permeability through frozen pig skin is independent of the effect of different formulations, placing a question mark on the validity of the not freshly-used porcine skin for in vitro penetration studies.
猪皮由于生化特性相似，常被用作体外渗透研究的模型，被视为人类皮肤的绝佳替代品。解冻后的冷冻皮肤用于这些研究尤为方便，因为随时都可获取。尽管一些研究人员已经注意到冷冻并解冻组织会导致药物渗透性增强，但许多已发表的文章仍描述了使用冷冻猪皮进行药品生物等效性和透皮评估的研究。因此，根据我们的经验，这篇评论文章的目的是明确证明，用于体外经皮研究的冷冻猪皮这种便捷方案的可靠性较低。在三项分别使用三种不同药物的研究中表明，与使用新鲜皮肤相比，冷冻/解冻后的猪皮对药物具有更高的渗透性。结果进一步表明，通过冷冻猪皮的异常渗透性与不同制剂的影响无关，这对非新鲜使用的猪皮用于体外渗透研究的有效性提出了质疑。
