Home Cosmetic Science Talk Formulating How to maximize Retinol stability in emulsions - Ideas and questions

  • How to maximize Retinol stability in emulsions - Ideas and questions

    Posted by Zink on April 29, 2014 at 11:24 pm

    Other than optimal storage conditions (fridge, opaque pump bottle minimizing air exposure). What are best practices for formulating with Retinol?

    Some ideas:
    1. High viscosity - less interaction between retinol and water molecules over time.
    2. High oil % - Studies show that 40% oil emulsions can increase stability 2x over a 15% oil emulsion. 
    3. Consider a 100% oil formula, use waxes to make a “salve”?
    4. Encapsulation through sonication with e.g. silica, make OWO formula (can be technically difficult, requires the right tools and materials).
    5. Antioxidants: Vitamin E, Vitamin C, BHT, BHA typically used.
    6. pH? What’s the optimal number.
    Anyone know what solvents or oils are best to improve Retinol stability? (theoretically, from studies or from experience) and what to avoid other than e.g. oxygen releasing agents and strong acids.
    Ruben replied 10 years, 1 month ago 3 Members · 4 Replies
  • 4 Replies
  • Ruben

    May 1, 2014 at 10:55 am

    @Zink I’ve been thinking about making an anhydrous retinol serum, but I haven’t seen any product of this type in the market and wonder why? Is it just because of the greasy feel? Or maybe there is another reason.
    There is a company that offers retinol in cyclodextrin that is supposed to be stable

  • Zink

    May 1, 2014 at 3:20 pm

    Anydrous would seem to make sense, possibly silicon based too? Seen any stability data? I remember seeing can remain stable in food oils for a long time at RT, but retinol is less stable.

  • simona

    May 1, 2014 at 3:51 pm
  • Ruben

    May 1, 2014 at 4:40 pm

    In fact retinol comes dissolved in corn oil or fractionated coconut oil, among other oils, so it must be stable. I was thinking about silicone too. I tried silicone with other actives and I’m happy with the results. Thank you simona for the link. This proves there is a silicone-based retinol product in the market.

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