title: Determination of sun protection factors. Correlation between in vivo human studies and an in vitro skin cast method.
abstract: Synopsis Sun protection factors were determined by both an in vitro method which used resin casts taken from replicas of human skin and by an in vivo SPF method. Thirty-eight product development samples were tested for the level of sun protection using both methods and the results were compared. The values obtained showed a positive relationship which was closely approximated by a log-linear regression of in vivo data on in vitro data (regression coefficient, r(2)= 0.86). It is concluded that the cast technique is quick, convenient, inexpensive and in its present form useful for screening sunscreen products prior to in vivo SPF testing.
authors.affiliation: The Boots Company plc, Nottingham NG2 3AA, UK.
authors.forename: J
authors.initials: J
authors.lastname: Ferguson
authors.forename: M W
authors.initials: MW
authors.lastname: Brown
authors.forename: A W
authors.initials: AW
authors.lastname: Hubbard
authors.forename: M I
authors.initials: MI
authors.lastname: Shaw