Seixas Vitor C, Serra Osvaldo A
Department of Chemistry, Faculty of Philosophy, Sciences and Languages of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP 14040-901, Brazil.
Molecules. 2014 Jul 9;19(7):9907-25. doi: 10.3390/molecules19079907.
Inorganic UV filters have become attractive because of their role in protecting the skin from the damage caused by continuous exposure to the sun. However, their large refractive index and high photocatalytic activity have led to the development of alternative inorganic materials such as CePO4 for application as UV filters. This compound leaves a low amount of white residue on the skin and is highly stable. The aim of this study was to evaluate the physical and chemical stability of a cosmetic formulation containing ordinary organic UV filters combined with 5% CePO4, and, to compare it with other formulations containing the same vehicle with 5% TiO2 or ZnO as inorganic materials. The rheological behavior and chemical stability of the formulations containing these different UV filters were investigated. Results showed that the formulation containing CePO4 is a promising innovative UV filter due to its low interaction with organic filters, which culminates in longer shelf life when compared with traditional formulations containing ZnO or TiO2 filters. Moreover, the recognized ability of CePO4 to leave a low amount of white residue on the skin combined with great stability, suggests that CePO4 can be used as inorganic filter in high concentrations, affording formulations with high SPF values.
无机紫外线过滤剂因其在保护皮肤免受持续日晒所造成损伤方面的作用而备受关注。然而，它们较大的折射率和高光催化活性促使人们开发诸如磷酸铈（CePO4）等替代性无机材料用作紫外线过滤剂。这种化合物在皮肤上留下的白色残留物较少，且稳定性很高。本研究的目的是评估含有普通有机紫外线过滤剂与5% CePO4的化妆品配方的物理和化学稳定性，并将其与含有相同载体且以5%二氧化钛（TiO2）或氧化锌（ZnO）作为无机材料的其他配方进行比较。对含有这些不同紫外线过滤剂的配方的流变行为和化学稳定性进行了研究。结果表明，含有CePO4的配方是一种很有前景的新型紫外线过滤剂，因为它与有机过滤剂的相互作用较弱，与含有ZnO或TiO2过滤剂的传统配方相比，其保质期更长。此外，CePO4在皮肤上留下少量白色残留物的公认能力以及出色的稳定性表明，CePO4可以高浓度用作无机过滤剂，从而提供具有高防晒系数（SPF）值的配方。
