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L Reppel

Publications and source records attributed to L Reppel.

13 recordsLinked to original sources

[Drug permeation through synthetic lipid membranes. Part 10: The effects of diffusion layers on the permeation process (author's transl)].

Two different processes take their courses during the permeation of substances through lipid membranes. The substance must pass across the diffusion layers on the membranes and also across the lipid barrier proper. The effects of these two processes on the permeation vary with the kind of the membrane and of the substance as well as with the diffusion layer thickness which is determined by the intensity of movement. Correlations have been established which permit to calculate diffusion layers, membrane permeation coefficients, and also diffusion coefficients in the diffusion layers. Thus have been provided the prerequisites for the comparison of results obtained on using different model parameters.

Diffusion↗

[Drug permeation through synthetic lipid membranes. Part 13: The effects of tensides on the permeation of ionized drugs (author's transl)].

The permeation of substances present in the ionized form is most markedly affected by tensides containing ions of opposite sign. These tensides produce a considerable increase in permeation. The effect of micelle formation will become evident only if the transport of the free drug through the membrane is more rapid than the release of the drug from the micelles. If the concentrations of nonionic tensides are less than the critical micelle concentration, a permeation increase occurs which is presumably caused by a reduction of the surface tension of the membrane.

Buformin↗