Enhanced transdermal permeability of estradiol using combination of PLGA nanoparticles system and iontophoresis

► Estradiol-loaded PLGA nanoparticles effectively delivered estradiol through rat skin. ► Iontophoresis enhanced permeability of estradiol/PLGA nanoparticles through rat skin. ► Main permeation route of estradiol and coumarin 6-loaded PLGA nanoparticles was follicles. ► Nanoparticle system efficiently delivered estradiol to blood by the combination with iontophoresis.