Strathclyde Institute of Pharmacy and BioMedical Sciences, University of Strathclyde, Glasgow, UK.
Eur J Pharm Biopharm. 2010 Mar;74(3):513-7. doi: 10.1016/j.ejpb.2009.12.003. Epub 2009 Dec 22.
There is mounting evidence that the permeability coefficients (k(p)) that describe any given transdermal drug permeation process generally follow some form of positively skewed, non-symmetrical distribution rather than a simple normal distribution. Yet a suitable theoretical treatment of this area has not been undertaken to date. In this paper, we describe a two-layer model that can explain five drugs'k(p) variabilities as measured in two previously published papers. The model shows why rapidly permeating drugs would tend to exhibit more symmetrical k(p) distributions while progressively more slowly permeating drugs would tend to exhibit progressively more positively skewed k(p) distributions. Future research should take this effect into account when comparing the flux variabilities of hydrophilic and lipophilic drugs.
越来越多的证据表明，描述任何特定透皮药物渗透过程的渗透系数（k(p)）通常遵循某种形式的正偏态、非对称分布，而不是简单的正态分布。然而，迄今为止，尚未对此领域进行适当的理论处理。在本文中，我们描述了一个两层模型，可以解释在之前发表的两篇论文中测量的五种药物的 k(p)变异性。该模型说明了为什么快速渗透的药物往往表现出更对称的 k(p)分布，而渗透速度逐渐较慢的药物则表现出越来越正偏的 k(p)分布。在比较亲水性和疏水性药物的通量变异性时，未来的研究应该考虑到这一影响。
