Health Effects Laboratory, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA.
J Pharm Sci. 2011 Jul;100(7):2989-95. doi: 10.1002/jps.22489. Epub 2011 Jan 31.
New data sets on both (i) equilibrium theophylline (TH) partitioning/binding in stratum corneum and (ii) transient TH diffusion through human epidermis are explained by an extended partition-diffusion model with reversible binding. Data conform to a linear binding isotherm within the tested concentration range (0-2000 μg/mL) with an equilibrium ratio of bound-to-free solute of approximately 1.4. The permeability coefficient for TH is 4.86 × 10(-5) cm/h, and the lag time is 20.1 h. Binding occurs as a slow process, significantly affecting the kinetics of dermal penetration.
新的数据集分别（i）平衡了角质层中环磷酰胺（TH）的分配/结合，以及（ii）TH 通过人体表皮的瞬态扩散，这都可以通过一个具有可逆结合的扩展分配-扩散模型来解释。在测试的浓度范围内（0-2000μg/ml），数据符合线性结合等温线，结合物与游离物的平衡比约为 1.4。TH 的渗透系数为 4.86×10(-5)cm/h，滞后时间为 20.1h。结合是一个缓慢的过程，显著影响了皮肤渗透的动力学。
