Phosphodiesterase type 5 inhibitors are drugs used to block the degradative action of phosphodiesterase type 5 on cyclic GMP in the smooth muscle cells lining the blood vessels supplying the corpus cavernosum of the penis. These drugs are commonly used in the treatment of erectile dysfunction.
Phosphodiesterase type 5 inhibitors are commonly delivered orally. Currently, no transdermal formulations of phosphodiesterase type 5 inhibitors have been approved by the FDA. Accordingly, systems and methods for transdermally delivering clinically useful amounts of phosphodiesterase type 5 inhibitors are needed.