They were applied in vitro to Yucatan micropig intact or stripped skin at apractical dose(2 mL/cm2). For stripped skin,penetration of DPH from 4%PMB EL was slower than tha tfrom 1% TO EL; results fo rintact skin
were similar.The same phenomenon was observed with application to rabbit skin in vivo. When 4% PMB EL dried on the skin,it made a thin film matrix incorporating the oil phase,which controlled the release of DPH.The release rate could be controlled by the ratio of oil phase to PMB.The EL with PMB
shows promise as a vehicle for long-acting treatment of skin diseases.