Showing 3 results for Sunscreens
Saman Ahmad Nasrollahi, Hesam Alibakhshi,
Volume 4, Issue 4 (12-2013)
Abstract
The use of sunscreens should also be recommended in order to work against all kind of ultarviolet (UV)-induced skin damage such as photoallergies, skin wrinkles, sunburn or even skin cancer. Sunscreens contain chemical filters (organic absorb regularly UVB radiation) and physical filters (e.g., TiO2 and ZnO). The second group has been said to reflect and scatter UVB and UVA radiation. TiO2 is also extensively used in sunscreen formulations as active broadband sunscreens that blocks both UVB (290–320 nm) and UVA (320–400 nm). Although titanium dioxide is listed as a safe pigment, with no known adverse effects when it is used in cosmetics, but we should concern about ultrafine or nanoparticle form of titanium dioxide. If titanium dioxide particles used to act as a sunscreen are small enough, they can penetrate the cells, leading to photocatalysis within the cell, and cause DNA damage after exposure to sunlight.
Mohammad Azad, Saman Ahmad Nasrollahi, Alireza Firooz,
Volume 5, Issue 1 (3-2014)
Abstract
Although ultraviolet rays constitute a small portion of the sunlight, they are destructive on skin. Ultraviolet rays cause sunburn, skin damage and skin cancers. Sunscreens are one of the most widely used cosmetic products which protect skin from cancer or other damages. There are two categories of sunscreen agents: chemical and physical. Physical sunscreens containing zinc oxide work through two mechanisms of reflection and scattering. Physical sunscreens are non-allergenic, non-irritating and non-comedogenic. Currently, by using zinc oxide nanoparticles in sunscreen formulation, both prevention of harmful sun rays and receiving cosmetic benefits are achieved.
Saman Ahmad Nasrollahi, Hurnaz Hassanzade, Taraneh Yazdanparast, Shadi Marami Zenouz, Mehdi Mohiti Asli, Alireza Firooz,
Volume 5, Issue 2 (7-2014)
Abstract
Background and Aim: Sunscreens are an important part of photoprotection strategy. They are exposed to strict safety evaluation using human subjects such as in vivo studies of skin irritation. Biophysical parameters measurements could be used as fast and noninvasive methods to measure any destructive effect of cosmetic formulations on skin application sites.
Methods: Five sunscreens were selected from Iran's market to determine changes in Transepidermal Water Loss (TEWL), stratum corneum hydration, pH, melanin and hemoglobin contents by biometric assessments with MPA 580Cutometer®.
Results: There was no significant change in skin pH, melanin and hemoglobin contents before and after sunscreen application. Significant change in TEWL and stratum corneum hydration after use of some sunscreens might be contributed by the occlusive and humectant ingredients which used in base cream.
Conclusion: Application of the studied sunscreens on human volunteers has not shown any adverse effects and these formulations could be recommended to use.
