Abstract:

Objective To determine the sun protection factor （SPF） and protection factor of ultraviolet A （PFA） of a self-made sunscreen cream. Methods The sample of a self-made sunscreen cream and a commercial sunscreen cream were painted to an artificial skin （3M film） at a dose of 2 μl/cm2, and a tester was used to evaluate their photoprotective effect. A total of 48 albinism guinea pigs were classified into 8 groups to remain unprotected or be protected by the self-made or commercial sunscreen cream. A solar ultraviolet light simulator （SUV-1000） was used to simulate the ultraviolet rays in sunlight to irradiate the guinea pigs, and the photoprotective effect of these sunscreen creams was determined. Results The in vitro evaluation revealed that the SPF value of the self-made sun-screen cream and commercial cream was 32.26 ± 2.42 and 30.87 ± 2.57 respectively （n = 5, t = 0.94, P > 0.05）, and the PFA value was 24.28 ± 2.44 and 17.53 ± 2.28 respectively （n = 5, t = 4.52, P < 0.01）. As the in vivo experiment showed, the SPF value of the self-made sun-screen cream and commercial cream was 30.39 ± 6.65 and 28.79 ± 7.36, respectively （n = 12, t = 0.38, P > 0.05） , and the PFA value was > 8.91 and > 8.93 respectively. Conclusion The photoprotective effect of the self-made sunscreen cream is similar to that of the commercial cream.

Key words: In-vivo of guinea pigs