Analysis of photokinetics of 2’-ethylhexyl-4-methoxycinnamate in sunscreens

Abstract

2′-Ethylhexyl-4-Methoxycinnamate (EHMC), also designated as octinoxate, is one of the most employed UVB absorbers in sunscreens for the protection of human skin against solar UV-radiation.

Effects of UV‐filter Photostabilizers in the Photostability and Phototoxicity of Vitamin A Palmitate Combined with Avobenzone and Octyl Methoxycinnamate

“…Therefore, OMC and AVO were not considered photostable in formulations without photostabilizers (F1 and F1 RP), which are in agreement with the reports from literature (10,14,39,41) since they are known as photounstable UV‐filters that must be formulated with photostabilizers to produce stable sunscreen formulations. In addition, OMC and AVO have been studied regarding their mechanism of photodegradation and photoproducts using both diluted solutions and formulations.…”

“…In a previous study, in ethanolic solution OMC showed no degradation after irradiation, but in the irradiated formulations OMC was significantly degraded (47). Thus, in diluted solutions (µM) the photoinstability of OMC might be related predominantly to the unimolecular photoisomerization trans/cis , but at higher concentrations in cosmetic formulations the concentration‐dependent bimolecular [2 + 2]‐cycloaddition can be detected (14,47). Meanwhile, it is well‐known that the photodegradation of AVO is induced by the keto‐enol tautomerization, followed by photodegradation reactions via triplet state leading to the loss of its effectiveness (10,48).…”

“…In addition, AVO may affect the photostability of other UV‐filters, and for instance, the photodegradation of the UVB‐filter octyl methoxycinnamate (OMC) is accelerated in the presence of avobenzone by [2 + 2]‐cycloaddition (14). This known photounstable combination is often used in many sunscreen products combined with photostabilizers, because both of them have a high molar extinction coefficient (AVO: 26 000 m −1 cm −1 ; OMC: 24 000 m −1 cm −1 ) and consequently a high absorption in the UVA and UVB region (15).…”

Elucidating the Photoluminescence Quenching in Ensulizole: An Artificial Water Soluble Sunscreen

“…Now a days, a number of different UV absorbing molecules nd their use in commercial sunscreens [19][20][21]. There are 27 registered compounds, which are used as UV-lter in Europe as sunscreens [8].…”

“…Protection against sunlight supports to avert skin damage from unnecessary and extended contact to the sunlight. Excessive exposure to the sunlight can perform a major role in degenerative variations in the skin like photoaging and skin cancer [7][8][9][10][11][12]. It has been proved that ultraviolet (UV) radiations cause erythema solare [13].…”