How to keep a fragrance fabulous forever

Estee Lauder once said, ‘perfume is like a new dress. It makes you quite simply marvellous’. However, a creased new dress, or perfume that has gone stale, could destroy the feeling of marvelousness in an instant.

Formulators often face serious challenges when formulating with lightsensitive ingredients and fragrance is among the most challenging. Fortunately, there is a solution – Diethylhexyl syringylidene malonate (DESM), the active ingredient in Oxynex ST liquid. DESM provides highly effective stabilisation of light-sensitive cosmetic substances and is particularly capable of protecting fragrances from unwanted changes in colour or smell.

The DESM in Oxynex ST is a unique molecule, which, with its specific structure, ensures light stability. DESM has a sterically stabilised phenolic function as well as the benzylidene malonate function. Together these two functions support the stabilisation of light sensitive ingredients.

The phenolic function provides the antioxidant functionality, the benzylidene malonate function is a photo-stabiliser and a triplet energy quencher and the carbon chain residues of the molecule ensure hydrophobicity, making this a processible liquid which is miscible with oil.

Superior stabilisation

Oxynex ST liquid not only offers protection for fragrances, but also stabilises dyes, vitamins and UV filters – at a relatively low concentration. For fragrances, the recommended addition rate is 0.5 percent whereas it can be as low as 0.1 one for dyes.

In various studies, Merck has been able to show that Oxynex ST liquid has superior stabilisation compared to traditional photo-stabilisers. For example, the photo-induced degradation of Vanillin was investigated photometrically.

The light absorption of an ethanolic solution of 0.1 percent Vanillin and approximately 0.5 percent DESM was measured at λmax 281nm.