N-alkylamides are a group of bioactive molecules found in several plants. Extracts and formulations derived from these plants are not only used orally, but are applied on the skin and buccal mucosa as well. However, there is no specific information available about the intrinsic local pharmacokinetics of N-alkylamides after topical application, questioning the role of this mode of administration. Therefore, we investigated the transdermal and transmucosal behaviour of spilanthol, a prominent N-alkylamide, in a commercial Spilanthes extract, two mouth gels and different propylene glycol (PG)/H20 solutions
