Through oil-water multilaminates

In this paper, solutions to three important heterogeneous diffusion problems are presented, and their implications for transport in biological systems are discussed. While the detailed methods of solutions and subtleties are presented in other papers (2-6), the asymptotic solutions are easily described, and they define the important physics of diffusion for most of the ranges of interest. In particular, a) nonsteady-state diffusion through oil-water multilaminates (2,3) b) desorption from oil-water multilaminates (4) and... 

Nonsteady-state diffusion through oil-water multilaminates has been used extensively as a model for the optimal biological response of a series of congeners with respect to partition coefficient (3,7, 8). Actual solution of this model reveals the deficiencies of multilaminates as a model for biological transport, but it does show the extraordinary separation factors of these multilaminates in the nonsteady-state regime. 

Nonsteady-State Permeation Through Oil-Water Multilaminates... 

Figure 1. Model for permeation through oil-water multilaminate of 2n-l membranes. (Reproduced with permission from Ref. 3. Copyright 1984 American Pharmaceutical Association.)...

The second diffusion problem, desorption from oil-water multilaminates, is considered as a model for (a) controlled release from liposomes and lipid multilayers and (b) for transport through biological laminates such as stratum corneum. In contrast to nonsteady-state transport across multilaminates, desorption from laminates depends only on the outermost layers. 

Desorption from an oil-water multilaminate should be an accurate model for controlled release from liposomes and lipid multilayers and may be helpful to understand transport through naturally occurring biological laminates such as stratum corneum. Asymptotic solutions based upon simple assumptions about the concentration profile may also be used to understand the desorption properties. 

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