Multiday Beach Study
Condition: Erythema
MeSH terms: Erythema
Study type: Interventional

Summary: 
      This is a randomized, double-blinded, single-center, split body and split face, multiple
      natural sunlight exposure evaluation of two marketed sunscreens under actual use conditions
      in healthy volunteers. Eligible subjects will be randomized to two treatment randomization
      groups: Left SPF (Sun Protection Factor) 100+/Right SPF 50+ or Left SPF 50+/Right SPF 100+.
      Assessment of erythema and pigmentation will be performed at baseline and after all natural
      sunlight exposure periods which will occur on at the same beach location over the course of 5
      consecutive days. Subjects will be suspended from further natural light exposure periods
      following the observation of sunburn at any exposed body site.
    

Detailed description: 
      Randomized, double-blinded, single-center, split body and split face, in use study under
      multiple exposures to natural sunlight conditions in healthy volunteers.

      Each subject will be instructed to self-apply the test products to the designated exposure
      body/face sites as they normally would for sunburn protection while at the beach. Exposure
      sites will be limited through the duration of the study to the face, neck, arms including
      shoulders and legs from the top of the knee down. Each of the two products will be applied
      exclusively to the exposure sites on the designated side of the body for the duration of the
      study. Product labeling will include a color coded indicator of application side and a
      standard sunscreen drug facts label containing usage directions.

      The difference in the level of sunburn (erythema) protection afforded and the level of UV
      (Ultraviolet) induced pigmentation (melanogenesis) response mediated by the typical usage of
      SPF 50+ and SPF 100+ sunscreens will be assessed by clinical evaluation. Erythema and
      melanogenic response will also be evaluated at fixed body site locations by diffuse
      reflectance spectroscopy (DRS) and chromameter assessment. Subject product usage will be
      tracked by recording tube weight before and after product use. Sunlight exposure behavior
      will be tracked by subject activity diaries.

      Solar ultraviolet radiation conditions will be recorded on a centralized stationary
      radiometer.

      Erythema protection afforded by the two products will be based on the bilateral sunburn
      comparison of matched exposure sites and the erythema score for each exposure area.

      Success criteria will be demonstration of superior sunburn protection of SPF 100+ as compared
      to SPF 50+ as indicated by less sunburn on the SPF 100+ side than the SPF 50+ side (based on
      bilateral sunburn comparison).

      Mediation of the UV induced pigmentation response afforded by the two products will be based
      on the bilateral pigmentation comparison of matched exposure sites and chromameter and DRS
      measurements.

      All subjects will be evaluated at baseline and at the beginning of each day.
    

Intervention name(s): 50/100; 100/50
Intervention type(s): Other; Other
Intervention description(s): SPF; SPF
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Prevention