Combining Ethylhexyl Salicylate and Butyl Methoxydibenzoylmethane

Question

When formulating with both liquid Ethylhexyl Salicylate and powder Butyl Methoxydibenzoylmethane, is it possible to mix them directly for dissolution, or is it necessary to pre-dissolve the powder in a solvent like DPG or another suitable solvent before adding to the formula?

MySkinRecipes Expert · Accepted Answer

Combining Ethylhexyl Salicylate and Butyl Methoxydibenzoylmethane

Butyl Methoxydibenzoylmethane, also known as Avobenzone, is a powder UV filter that needs to be fully dissolved in the oil phase of a formulation to be effective and stable. Ethylhexyl Salicylate (Octisalate) is a liquid UV filter that is oil-soluble and can act as a solvent for Avobenzone.

Can they be mixed directly? While Ethylhexyl Salicylate can help dissolve Butyl Methoxydibenzoylmethane, simply mixing the powder directly into the liquid might not ensure complete or rapid dissolution, especially at higher concentrations. It is generally recommended to ensure the powder is fully dissolved before incorporating it into the main formula.
Pre-dissolving in a solvent: Yes, it is a common and recommended practice to pre-dissolve Butyl Methoxydibenzoylmethane in a suitable solvent before adding it to your formulation. Ethylhexyl Salicylate itself can be part of this solvent system. Other oil-soluble solvents commonly used for dissolving Avobenzone include C12-15 Alkyl Benzoate, Octyldodecanol, or other liquid UV filters that have good solvency for Avobenzone.
Using DPG: Dipropylene Glycol (DPG) is a polar solvent. While it can dissolve some organic compounds, oil-soluble UV filters like Butyl Methoxydibenzoylmethane are typically more soluble in non-polar or less polar oil-based solvents or esters. Using DPG alone might not be the most efficient way to dissolve Avobenzone compared to using oil-based solvents or liquid UV filters with good solvency. However, in some complex solvent systems, DPG might be used in combination with other solvents.

Recommendation:

The best approach is to pre-dissolve the Butyl Methoxydibenzoylmethane powder completely in a suitable oil-soluble solvent or a blend of solvents, which can include Ethylhexyl Salicylate, before adding this solution to the rest of your formulation. Gentle heating can often help speed up the dissolution process. Ensure the powder is fully dissolved and the solution is clear before proceeding.