Lecithin organogels as matrix for the transdermal transport of drugs.

The stable, transparent, thermoreversible organogels which are prepared by adding a minute amount of water to a solution of lecithin in isopropylpalmitate are studied as matrices for promoting the transdermal transport of drugs throughout the skin. In this work we study this process by using two model drug substances, scopolamine (already well known as a transdermally active substance) and broxaterol, a new drug against asthma. It is found that the transport of scopolamine is much more effective in gel than in aqueous solution and that the transport of broxaterol is also proceeding well. Since the same can be observed with a variety of substances differing in the chemical structure, we speculate on the application of lecithin gels as general matrices for the transdermal transport.