The Effect of Molecular Weight of Drugs on Transdermal Delivery System Using Microneedle Device

We developed the successive roller type of microneedle system without pain to improve the permeation of drug through the skin barrier. The permeation rates of FITC-ovalbumin (OVA, MW: 45,000g/mole), FITC-insulin (MW: 5,733 g/mole) and FITC-bufexamac (MW: 227.37 g/mole) as model drugs were determined by modified Franz diffusion cells using the microneedle device with four times treatment. The average penetration fluxes of FITC- OVA, FITC-insulin and FITC-bufexamac were steeply increased from 13.4 to 83.3, 10.1 to 110.6 and 11.9 to 242.6 pmol/cm2 with treatment for 12 hrs, respectively. The lower the molecular weight of the drugs, the more the permeation flux investigated. In conclusion, we confirmed the possibility of the application for transdermal delivery of the larger molecular drugs as protein using the designed microneedle treatment device.