photometer to measure the absorbance from 250 nm to 400 nm.
The ultraviolet spectrophotometer method was used to evaluate
the UVB protection effects of the CDBA-liposomes according to
the QB/T 2410-1998 (a standard method issued by China National
Light Industry for evaluating UVB protection effects of sunscreens
by ultraviolet spectrophotometer method). Meanwhile, the critical
wavelength was also calculated according to the critical wavelength method [19]. Based on the result, the UVA protective effect
of the CDBA-liposomes was classified.
2.9. Assessing the repeatable UV protective efficacy of CDBA-liposomes
in vitro
Simulation test in vitro was carried out to assess the repeatable
UV protective efficacy of CDBA-liposomes before animal experments. CDBA-liposome solution and avobenzone-liposome solution were irradiated for 3.5 h at a distance of 15 cm from UV
light source and then placed under fluorescent lamps (645 LUX)
for 1 h. The UV–Vis absorption spectra of CDBA-liposomes and avobenzone-liposomes were measured.