What it is
Diisopropyl sebacate is a clear, colorless ester formed from sebacic acid and isopropyl alcohol. In cosmetics it works as both an emollient and a solvent, and it is particularly useful in sun care because it dissolves oil-soluble UV filters and helps formulators build higher-SPF products with a lighter, more elegant feel. It absorbs quickly, improves spreadability, and reduces the heavy, greasy character that concentrated UV filters can otherwise give a formula.
Safety & warnings
Diisopropyl sebacate is used as a cosmetically elegant emollient and filter solvent and is common in modern sunscreen formulations. It is selected partly because it helps deliver high SPF with less of the tackiness associated with heavy filter loads. As with other ester emollients, individuals with very reactive skin may wish to patch test.
Origin & sourcing
It is a synthetic ester. It is produced by esterifying sebacic acid, a ten-carbon dicarboxylic acid that is itself derived from castor oil through cleavage of ricinoleic acid, with isopropyl alcohol. This gives a partly bio-based starting material converted into a defined cosmetic ester.
Questions everyone asks
Why is diisopropyl sebacate used in sunscreen?
It dissolves oil-soluble UV filters and helps create lighter, higher-SPF formulas that absorb quickly and feel less greasy.
Is it natural or synthetic?
It is a synthetic ester, though its sebacic acid component is derived from castor oil.
Does it moisturize?
It acts as an emollient and skin-conditioning agent, helping soften skin and improve a product's spreadability.