Home Cosmetic Science Talk Formulating The shampoo does not increase in viscosity

  • The shampoo does not increase in viscosity

    Posted by alsmith on May 6, 2024 at 5:25 am


    I’m currently trying to develop a shampoo and I don’t have much knowledge about shampoos, so I thought I’d ask you guys.

    1. I don’t have a senior, is there any way I can study cosmetics?

    2. I want to know the process of making a typical shampoo (ex: heat the aqueous layer to 70℃, then add the oil phase layer)

    3. I would like you to look at what is wrong with my current recipe because the viscosity is not increasing and the transparency is also decreasing, is it because it is not defoaming?

    Water : 43.8%

    ASCO AOS-1416(30% sol) : 25%

    AKTAINE CB-35(27% sol) : 10%

    Dipropylene Glycol : 5%

    Mitaine DLS(H) (38% sol) : 4%

    APG1214 : 0.5%

    PQ-10 : 0.5%

    PQ-22 : 0.5%

    PQ-67 : 0.1%

    NACL : 2%

    EDTA (10% sol) : 0.1%

    EHG : 0.3%

    Citric Acid (10%) : 0.2%

    Additives : rest

    Adamnfineman replied 5 days, 8 hours ago 4 Members · 10 Replies
  • 10 Replies
  • ketchito

    May 6, 2024 at 8:59 am

    Remove dipropylene glycol. Solvents of this type serve no purpose in these kind of products, and can be impairing your viscosity.

    • alsmith

      May 7, 2024 at 2:44 am

      Thank you for your response.

      I will eliminate the Dipropylene Glycol to dissolve the Salicylic Acid.

  • Adamnfineman

    May 6, 2024 at 10:26 am


    Is that 0.1% EDTA the active matter added or the amount of solution added? If it’s the latter, I would increase it to have at least 0.1% active. Also, someone correct me if I’m wrong but I don’t think EHG and EDTA are enough on their own to form a robust preservative system.

    When adding up the % I got 92%. Depending on what they are, 8% of additives could greatly affect your viscosity and clarity.

    • alsmith

      May 7, 2024 at 2:46 am

      Thank you for your response.

      So would adding more hexanediol be enough of a preservative? Or do I need to find another preservative source and add it as well?

      Also, could you look at the other parts of the recipe to see if there’s anything weird?

      • Adamnfineman

        May 8, 2024 at 8:47 am

        I would recommend adding a preservative such as phenoxyethanol in a 1:9 EHG:PE ratio. We generally use 1% of this ratio along with 0.1% EDTA for our hair care products without issue. It’s sold as a blend by suppliers, my go to is Euxyl PE 9010.


        I do find it weird that you’re omitting 8% of the formula. Especially when based on your other comment part of that includes salicylic acid, which is notoriously finnicky.

        • alsmith

          May 9, 2024 at 12:17 am

          Can I use hexanediol instead of phenoxyethanol?

          And the 8% blank is the part with extracts, peptides, etc., is that too much?

          • Adamnfineman

            May 9, 2024 at 7:55 am

            I can’t say definitively whether that would be enough because I haven’t tried and tested that combination. Maybe @PhilGeis can shed some more light on this.

            I don’t know whether it’s too much as I don’t know what it is exactly. I do know that (most) extracts and peptides have little to no effect in leave-on products and even less in a rinse-off products like shampoos. What exactly are your additives? Are they being added for claims or efficacy? If efficacy, what do you expect them to do?

            • PhilGeis

              May 9, 2024 at 9:21 am

              Good perspective. To OP’s question

              More hexanediol. I don’t see it in the ingredient list - to that, please use chemical or INCI names. Maybe missed a commercial name.

              For shampoos/surfactants - rinse-off products, chloromethyl isothiazolinone is more traditional esp with EDTA and benzoate*. Phenoxy/EHG/Benzoate/EDTA is prob pretty effective. Unless you’ve resources to qualify a diol, suggest you not chase it.

              * not for fungi, they rarely cause issues in surfactant products, but as co-preservative, esp. to mitigate adaptation to the primary. Na benzoate serves this well and is effective beyond it’s pKa when combined with many surfactants (i.e. demonstrable efficacy up to pH neutrality).

            • alsmith

              May 13, 2024 at 4:56 am

              Thank you for your response. I would like to eliminate the use of Phenoxyethanol, is there an alternative source?

  • Adamnfineman

    May 14, 2024 at 7:49 am

    There are many other choices. @PhilGeis has listed some of them above. Do you have any other constraints when it comes to preservatives?

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