Tumor metastasis accounts for 90 %of cancer-associated deaths and is almost inaccessible by chemotherapy,surgical operation or radiotherapy.Before distant spreading,metastasized cancers have invaded the lymphatic system as a first step in their progression [1].Hence,effective control of the disease state of the lymphatics which drain a tumor site is crucial to treatment.Transdermal drug delivery could avoid the first-pass hepatic effect and fluctuation of blood concentration,and greatly facilitate drug accumulation in the lymphatics [2].