The determination of a diffusional pathlength through the stratum corneum

The stratum corneum possesses a very heterogenous structure. As such a diff using molecule can access a number of different pathways. It is probable th at the excellent barrier properties of the stratum corneum result from a to rtuous diffusional pathway around the dead cells. However, there are consid erable problems in designing diffusion experiments and analysing the data t o prove, without doubt, which is the predominant pathway. The mathematical problems posed are discussed in this article. (C) 1999 Elsevier Science B.V . All rights reserved.