Yorkshire pigs were clipped 24 hours before exposure.
The antioxidant or vehicle formulations (500
L) were applied to each patch of back skin (7.5
10 cm) daily for 4 days. To determine the minimal
erythema dose (MED), on day 3 we gave 30 to 100
mJ/cm2 at 10-mJ/cm2 intervals of solar-simulated
UVR to untreated skin. On day 4, MED was determined
as the lowest dose that induced perceptible
erythema with distinct borders (ordinarily 40-60 mJ/
cm2). From 1 to 5 MED at 1-MED intervals of
solar-simulated UVR was given in triplicate to each
7.5- 10-cm area of back skin. On day 5, the
antioxidant protection factor was calculated for each
formulation as the ratio of the MED in antioxidanttreated
skin in comparison with untreated skin. Each