[Drug permeation through artificial lipid membranes. 17. The mechanism of ion pair transport].

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 carrier for the ionized drugs. Then the necessary compensation of the charges can take place by protons or other suitable ions of the used solution.