Home Cosmetic Science Talk Formulating this doesn’t seem stable to me….? right??

  • this doesn’t seem stable to me….? right??

    Posted by Juggsy on March 13, 2023 at 10:51 am

    Hey CCers<div>

    I came across a post on one of the Facebook formulating groups which said:

    [quote]For the shampoo (the round cake), I melt SCI powder and use Cetearyl alcohol instead of BTMS since they are similar ingredients, and Cetearyl is inexpensive.

    Note: to avoid further discussions about BTMS. I use other conditioning ingredients in my formula. Cetearyl adds better hardness to the bar.[/quote]

    When asked by someone what their emulsifier was, as mixing water and oil without an emulsifier wouldn’t produce a stable formula. their response was :

    [quote]This is interesting input.

    I had been making different formulas with cetearyl alcohol for a couple of years, and one of them was absolutely unstable since it relied only on Cetearyl.

    This current formula, aside from powdered surfactants, contains Cocamidopropyl betaine, propanediol, Cocamidopropyl PG-Dimonium Chloride Phosphate, and some other ingredients that altogether improve stability, conditioning properties, and performance.

    I will look at Jeesperse and Jeequat as alternatives. [/quote]

    I have only been studying cosmetic chemistry for a couple of years (still a ways off being where I want to be).

    But… the other commenter is correct, right?

    I thought that cetyl and cetearyl alcohols both technically had high HLB (15?) so they need something to balance.

    I understand if there’s no oil in product they wouldn’t need to emulsify.

    So, like if there was

    82% Powdered Surfactants 18% Liquid phase (water,. humectants, maybe some guar hydroxypropyltrimonium chloride)

    would create a syndet shampoo bar that is stable, may not be good though.

    But surely, you can’t just chuck some cetearyl and cetyl alcohols and decide it’s stable.

    Which leads me to my next question…

    The OP has stated to every person that questioned them that their “formula” worked well.

    But, how? Is it just staying together like glue because it has a correct wet/dry balance?

    Would the bar be delivering both oil/water proponents separately and therefore not correctly washing hair?

    Or am I missing something? If so, enlighten me.

    (unsure if this is right forum discussion. I was going to ask in ‘change my viewpoint’ but thought it’s more formulating related.

    TIA 🤗

    ozgirl replied 6 months, 2 weeks ago 3 Members · 4 Replies
  • 4 Replies
  • ozgirl

    March 13, 2023 at 6:28 pm

    In shampoo bars, cetearyl alcohol is generally used as a bar hardener / filler. It is not an emulsifier.

    Shampoo bars generally contain no or very little water and do not behave like emulsified products. The raw materials are just blended together with very little interaction.

    The surfactants in shampoo bars are probably sufficient to emulsify any oils in the shampoo bar during use. I personally don’t use oils in shampoo bars because you are basically just washing them down the drain without any benefit. Cationic conditioners that can attach to the hair are a better choice (IMO).

    BTMS-25 is generally a blend of BTMS and Cetearyl Alcohol. So swapping it out for cetearyl alcohol and adding a different cationic conditioner is a valid choice as in the context of shampoo bars because it is not acting as an emulsifier but is acting as a bar hardener and cationic conditioner.

    Hope this helps. 🙂

    • Juggsy

      March 14, 2023 at 8:05 pm

      You didn’t read the whole thing?

      I understand that fatty alcohols act as bar hardeners and personally use them as such.

      My issue isn’t them using it as a bar hardener. Have no issue with them using as hardener in a surfactant bar but they aren’t doing that. My issue is them using oils (which they say they are using) and not replacing the BTMS50 with another cationic emulsifier. It was suggested to the OP to change the BTMS50 to a cheaper cationic emulsifier (it was even suggested how to use BTMS with cetyl alcohol) or to remove the oil phase and replace it completely with other conditioning agents (humectants, quats etc).

      I don’t see how a fatty alcohol can act as a stand alone in this case. My understanding is (please correct, if I’m wrong) that fatty alcohols are not surfactants as they have different molecular structure, different interfacial activity, different way of interacting with surfactants. How can something with no charge replace something with charge and still be effective?

  • abdullah

    March 14, 2023 at 8:18 pm

    Is this your question that how can they add oils without emulsifier?

    They have a lot of surfactants and surfactants are emulsifiers.

    If not then what is your question?

  • ozgirl

    March 15, 2023 at 7:49 pm

    I did read it all but it got a little bit confusing. So I tried to provide some information.

    You are correct that cetearyl alcohol isn’t an emulsifier but the remainder of the bar is usually 60 to 80% surfactants (e.g. SCI, SLS, SCS and SLSA) which act as emulsifiers for the oils during use. It is my understanding that because there is no (or little) water in these bars that you aren’t making an emulsion during manufacture, it is just a blend of ingredients until you start using it. At the point of use when water is added if there are oils present then the emulsion is created. You could compare it to something like a bath bomb where there is no interaction between the ingredients before it is used.

    BTMS is usually only added for conditioning so it can easily be left out or swapped for another conditioner.

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