Dendrimer polyamidoamine (PAMAM) is a new type of hyper branched and three dimensional macromolecule which possesses properties of monodispersion, non immunogenicity, low cytotoxicity and biodegradation. As drug carrier, PAMAM can increase the solubility of the drug, delay drug release, increase the skin permeability coefficient, prolong the residence time in cornea and increase the bioavailability of the drug. It might be a potential and novel drug carrier. In our study, puerarin was choosen as the model d...