PERCUTANEOUS PERMEATION OF BETAMETHASONE 17-VALERATE FROM DIFFERENT VEHICLES

In vitro percutaneous permeation of betamethasone 17-valerate through excised human skin was examined using four different vehicles. The mea n drug flux from the pressure sensitive silicone adhesive which contai ned the drug as a suspension was 2.4-times greater than that from a 1. 2 mg/g commercially available cream which also contained the drug as a suspension. The latter was comparable to the mean flux from aqueous s aturation (5.5 mug/ml) and 4.1-times larger than that from 0.12 mg/g c ream. The aqueous vehicle did not show an enhancing effect on the perc utaneous permeation of betamethasone 17-valerate because the flux from the aqueous saturation was within a factor of 2.5 when compared to th e value from the suspension in the silicone adhesive and commercially available cream. Aqueous saturation concentration may provide the repr esentative unit activity flux of corticosteroid through the skin.