Home Cosmetic Science Talk Formulating Water soluble structuring agents for AHA/Retinol/Vitamin C

  • Water soluble structuring agents for AHA/Retinol/Vitamin C

    Posted by kiffemoa on April 7, 2021 at 9:41 am

    Good morning all! 

    I love listening to Perry’s podcast and I’ve enjoyed reading through the different discussions here on the forum. 

    I’m wondering if you know of any water soluble structuring agents that would be able to work with AHAs, Retinol or Vitamin C. I’m working with my chemist on these products in a solid format which is proving to be a little bit of a challenge! For sodium stearate would give a nice feeling to the product, but if we try to bring the pH down, the structure won’t hold with sodium stearate - if you leave it high, the AHAs won’t perform. 

    I want to give the customers a nice feel, while at the same time preserving the effectiveness of the actives used. 

    • For the AHA stick, we’re using a blend of lactic and mandalic acid. 
    • For the Vitamin C stick, we’re using Tetrahexyldecyl ascorbate.
    • For the retinol stick, we’re using Granactive Retinoid (Dimethyl Isosorbide, Hydroxypinacolone Retinoate) 

    Currently there is nothing else in the formula other than caprylic capric triglyceride as we are just working on the texture/structure.

    Thank you in advance, 

    kiffemoa replied 3 years, 2 months ago 5 Members · 5 Replies
  • 5 Replies
  • chemicalmatt

    April 7, 2021 at 7:28 pm

    “the AHAS won’t perform” at a higher pH is a misconception. Yes they will they simply take longer to work on desquamation at pH 5.0 - 6.0. Safer and less irritating too. Also, that sodium stearate will not gel polyols & ethanol at a lower pH should have been obvious to the formulator, jus’ sayin’. 

  • Pharma

    April 8, 2021 at 6:35 pm
    What do you mean by ‘water structuring’? That sounds like straight out of esoteric literature :smiley: .
    Couldn’t you just use a different pH insensitive emulsifier? There are tons to choose from.
  • MarkBroussard

    April 8, 2021 at 7:11 pm

    I think what @kiffemoa explained, but not in a direct manner, is that these products are solid sticks and sodium stearate is the “structuring agent” … what she really means is it is the gelling agent / emulsifier to form the solid stick.

    Just my two, but I would use a butters/oil/waxes combination for the Vitamin C and Retinoid sticks.  And for the lactic/mandelic acid use a roll-on format as opposed to a solid stick.

  • ngarayeva001

    April 9, 2021 at 11:49 pm

    To add to previos comments,Tetrahexyldecyl ascorbate is oil soluble and will perform better in oil based product. Although it is more stable tha LAA it still oxidises in presence of water.

  • kiffemoa

    April 12, 2021 at 1:58 pm

    Hello! Thank you for all your comments and tips. Indeed, as a consumer I wanted the sticks to have more of a wet feel to them rather than oily hence the sodium stearate but this might effect the other ingredients. But I must admit, I am but a humble brand founder - I am a little out of my depths! 

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