Sunscreen Liquid Foundation Containing Naringi Crenulata Powder

摘要

Powdered bark and stem of Naringi crenulata or thanaka, the traditional sunscreen cosmetics, were sun protection factor (SPF) analyzed. SPF of the bark powder (1.51 ± 0.31) was comparable to TiO_2 (1.99 ± 0.09), whereas that of stem was lower (1.13 ± 0.04). The optimum liquid foundation formula contains N. crenulata bark powder (10% w/w), TiO_2 (12% w/w) and natural SPF booster (Aloe vera powder, 2% w/w). This broad spectrum sunscreen (critical wavelength = 387.900 ± 0.000 nm) potentially protected UVB (SPF = 35.467 ± 0.136) and UVA (5th boots star). This porcelain natural liquid foundation determined by CIELAB system was stable under heating-cooling for 6 cycles and one month storage at 4, 25 and 45°C, separately, with a consistence of pH and viscosity. Its UVA protection efficiency was maintained and SPF was not significantly reduced. This presenting new herbal sun protection liquid foundation is available for cosmetic industry and would be further developed to prolong its efficacy including preference test in the panelist.