Desarrollo de una formulación cosmética, con colorantes fotocrómicos, indicadora del nivel de radiación ultravioleta absorbida

In this work we study the possibility of controlling the UV radiation exposure time, using creams with photocromic colorants. The change of the maximum colour of the colorant must coincide with the end of the commercial sun creams protection. We studied a set of factors that controls the time in changing the photocromic colour. We analyzed the answer of some individual components of the creams radiated with UV light and also the photocromic behaviour with some components of the creams. We present a hypothesis in order to show the mechanism which explains the change of colour. Finally we tested the action of the UV radiation on the final formulation of the cream verifying our hypothesis.