Abstract:

SPF 290S was used to test the SPF value of sunscreen products in vitro, and the consistency with the results of in vivo method was compared. The experimental conditions for the determination of SPF values by in vitro instrument were studied. PMMA plate or HD6 plate were used as the substrate, samples were coated at a dose of 2 mg/cm ², and placed in room temperature for 30 min. Under this condition, a more stable and reproducible SPF value in vitro measurement results could be obtained. Studies on the products define that inorganic sunscreen agents（including zinc oxide and titanium dioxide） can affect the consistency of in vitro and in vivo methods, and sunscreen products without inorganic show good consistency. Products containing inorganic sunscreen agents show poor consistency.

Key words: sunscreen cosmetics, SPF, in vitro instrument test