To determine the kinetics of photoprotection of
combination 15% L-ascorbic acid and 1% -tocopherol,
applications were made at 1, 2, 3, and 4 days.
Progressive protection as measured by erythema
and sunburn cells was observed (Fig 5). To determine
if the dosage was critical, the amount applied
during 4 days (2 mL) was applied 30 minutes before
irradiation (Fig 6). Single application of the entire
amount (2 mL) produced appreciable but incom-