Wolfgang Fuerst

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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(More)
Zinc is able to form complexes with 8-hydroxyquinoline (HC). Therefore the penetration of HC from topical formulations into the ear of guinea-pigs and into a multilayer membrane system was decreased by Zi. Using the AUC a suitable in vitro-in vivo correlation was obtained. An exception was observed when there were interactions between the ointment base and(More)
The transport of ionized drugs across lipoid membranes can be increased considerable by lipophilic counter ions. This is caused by an increased lipophilicity of the ion pair which is formed between the ionized drugs and the lipophilic counterion. Caused by their very strong solubility in the membrane the lipophilic counterions accumulate and act like a(More)
Using hexylsalicylic acid it was demonstrated that alkylated derivatives of salicylic acid are able to increase partition and transport of ionized basic drugs across lipophilic membranes. The influence of different donor concentrations on the relation of transport was studied by means of pholedrine in combination with hexylsalicylic acid. In order to(More)