Home Cosmetic Science Talk Formulating Extracts only dissolve in Ethanol. How to avoid it?

  • Extracts only dissolve in Ethanol. How to avoid it?

    Posted by marinaartm on October 22, 2019 at 8:08 am

    Hello!

    I bought some powder extracts: saw palmetto, red clover, resveratrol, olive leaf that are dissolvable in water+ethanol, mostly ethanol. I can not make creams with ethanol.  Is there any way to evaporate or eliminate the ethanol after i dissolve the extracts in water?

    Please help me out

    Thank you!

    pharma replied 4 years, 4 months ago 3 Members · 4 Replies
  • 4 Replies
  • belassi

    Member
    October 22, 2019 at 4:59 pm

    You can make creams with ethanol but you’d need to use airless packaging.

  • pharma

    Member
    October 24, 2019 at 7:20 pm

    The problem is that said extracts, or rather the active constituents therein, are lipophilic (i.e. fat/alcohol soluble). Fairly often (for economical and toxicological reasons) such extracts are for said reason made with ethanol (or supercritical CO2 but then cost more). Therefore, re-solubilisation is only possible with similar solvents. You may try to evaporate the solvent and reconstitute in glycerol or a glycol. Since an extract (apart from pure resveratrol) obtained by ethanol extraction contains a mixture of medium polarity compounds, the obvious and only “good” solvent is ethanol. Water will only dissolve some constituents, oils only others. Although, you may want to add your solvent of choice before evaporation (just make sure it doesn’t evaporate too!) and not to the dry, sticky mess after evaporation because for a bunch of reasons (some of which are unknown) such a dry or semi-dry (in pharmacy it’s called a spissum extract) will often no longer fully re-dissolve even in the original solvent. That’s one reason why several extracts are only sold as diluted solution. On the other hand, the ethanol % in the final product might be very small and will not really impact your product neither will a possible evaporation of that ethanol.

  • belassi

    Member
    October 24, 2019 at 11:41 pm

    I gave up on resveratrol. In order to get any decent percentage into solution I had to have a high percentage of alcohol in the cream. I think I ended up using a COSMOS compliant formula, no preservative (the ethanol level was high enough) but inevitably, even with an airless container, the ethanol migrates out and the ethanol percentage drops, putting preservation at risk, and the resveratrol forms clumps, most unpleasant. 

  • pharma

    Member
    October 25, 2019 at 6:25 pm

    Did you try PEG-400? It’s said to be soluble at 37% in there. CLICK

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