Lipophilisation of hydrophilic compounds. Consequences on transepidermal and intestinal transport of trospium chloride.

Lipophilic ion pairs of trospium chloride (Spasmex) were synthesized and the transfer rates of the parent drug and the derivatives across everted rat intestine and human abdominal epidermis were measured. It was evaluated whether there is a correlation between membrane permeation and hydrophilic/lipophilic balance. With some ion pairs of trospium, enhanced transport rates in both models could be found.