Photoprotective measures of selected sunscreens and their antioxidant adjuvantion effects in the Malaysian climate.

摘要

The Malaysian skincare industry is growing rapidly with a vast number of newudsunscreens being produced annually. Inadequate skincare regulations and lack ofudenforcement have resulted in the overrating of sunscreens’ quality. The objectivesudof this study were to evaluate the efficacy and safety of the local and internationaludsunscreens and to determine the effects of adding concentrated antioxidants intoudthem. Three local and three internationally manufactured sunscreens were tested forudthe in vitro Ultraviolet A protection factor (UVAPF), Sun Protection Factor (SPF) andudphotostability. The creams were spread onto roughened polymethylmethacrylateudplates where the absorbance was measured using a spectrophotometer before andudafter two hours of sunlight irradiation. The procedure was repeated combiningudavailable concentrated vitamin C and E creams. International sunscreens wereudfound to have more accurate SPF labels (p=0.009) while local sunscreens wereudfound to be more photostable (p=0.003). However, both sunscreens had inadequateudUVAPF (p=0.471). Vitamin C enhanced the SPF values (p= 0.04) of both groups ofudsunscreens while vitamin E enhanced their photostability (p=0.000). Interestingly,udcombining vitamins C and E rich creams with the sunscreens had no effect on theudSPF and UVAPF values as compared to the use of a single vitamin. More importantly,udthe combination of vitamins decreased the photostability (p=0.002) of sunscreensudas compared to the addition of vitamin E alone. In conclusion, photoprotection isudbest achieved when sunscreens are used together with creams containing eitherudvitamin C or E alone.udududKHAMSIAH N1, LAI NS2, NURFARHANIM M2, NOR AIMI AR2, MOHD SYAZWAN CS2, GOON JA