Home Cosmetic Science Talk Formulating 0.5% thickener is very watery

  • 0.5% thickener is very watery

    Posted by hatasamatter on January 17, 2024 at 10:01 am

    Hi! I’m a wannabe cosmetic formulator and I’m experimenting with various gum thickeners, e.g. Xanthan Gum and Tragacanth (Astragalus gummifer gum), on a quest to find out which one is the best one for my purposes.

    These are my formulations:


    Keltrol CG-T (INCI: Xanthan Gum) - 0.5%

    Euxyl K 712 (INCI: Sodium Benzoate (and) Potassium Sorbate (and) Aqua) – 1%

    Aqua – ad 100%

    Citric acid – q.s., pH = 5.5 (I used about 0.015g)

    Polynat T11 (INCI: Astragalus Gummier Gum) - 0.5%

    Euxyl K 712 (INCI: Sodium Benzoate (and) Potassium Sorbate (and) Aqua) – 1%

    Aqua – ad 100%

    Citric acid – q.s., pH = 5.5 (I used about 0.015g)

    I expected a gel-like consistency, but at 0.5%, both my Xanthan Gum and my Astragalus Gummifer Gum product have a very runny, almost water-like consistency. See the videos I made of the various concentrations:


    My manufacturing process:

    I weighed out the water and preservative and heated it up under stirring. Once this phase had reached about 55°C, I slowly added the gum, stirring until completely dissolved. I then let the concoction cool down to room temperature and adjusted the pH.

    I’m wondering why my thickeners at 0.5% concentration didn’t have any noticeable effect, if this is normal and where I might have gone wrong (too high temperature, wrong preservative, pH, …)?

    Any advice is greatly appreciated. Thank you so much!

    hatasamatter replied 4 months, 3 weeks ago 3 Members · 3 Replies
  • 3 Replies
  • chem.ist

    January 19, 2024 at 10:08 am


    I’m a new formulator as well but this is how i normally start a formula.

    Add thickener to water first. In this case you are using gums, id SLOWLY add these to the water if you are not premixing them with a humectant like glycerin or propanediol. If you do decide to premix you’ll see that it will disperse and the mixture will be more homogenous without having chunks. (Since youve been premixing the preservative, you dont know if thats the issue bc you havent seen how the thickeners work on their own)

    Once you see how the thickeners work on their own, you can decide to increase or decrease the concentration based on your desired viscosity. After that you can see if your other ingredients increase or decrease the viscosity of your product as well. Some thickeners are responsive to changes in pH, you should be fine with xanthan gum, im not sure about the other. I have had issues with preservative compatibility in the past where you make a great thick moisturizer and then once you add the preservative at the end, it breaks the whole formula nad makes it runny or chunky.

    Hope that helps!

  • chemicalmatt

    January 19, 2024 at 11:27 am

    As @chem.ist explains: always disperse gum resins directly into room temp water first before adding any other component, then begin heating while mixing. “That’s a fact Jack.” As for your “watery” outcome, this is no surprise and you did nothing in error that I can tell. Both xanthan and tragacanth are piss-poor at thickening. A 0.50% mucilage of either will not generate more than 300 cps or so. Both gums ARE good however at contributing yield value to your formula (suspension in 3 dimensions) which is why both are primarily only used as stabilizers not thickeners.

  • hatasamatter

    January 22, 2024 at 11:48 am

    @chemicalmatt @chem.ist Thank you so much for your help - I really appreciate it!

Log in to reply.