Effect of the absorption enhancer, Azone, on the transport of 5-fluorouracil across hairless rat skin.

The effect of the percutaneous absorption enhancer, Azone, on the transport of 5-fluorouracil across hairless rat skin has been investigated by an in-vitro permeation technique using 2-chamber diffusion cells. Azone (3% w/v) emulsions were used. Azone enhanced the permeability of drug 10-100 times across the full-thickness skin although there was a lag time about 10 h. The long lag time, however, disappeared with Azone pretreatment. Azone also affected the transport across stripped skin. These results suggest that Azone mainly affects the stratum corneum. It seems to change the diffusivity of drug in that layer and is not so effective against diffusivities in the epidermis and dermis.