Home Cosmetic Science Talk Formulating pH adjusters for shampoo

  • pH adjusters for shampoo

    Posted by em88 on June 7, 2017 at 7:06 am

    Greetings, 
    I have a question regarding pH adjusters for shampoo and more exactly substances that can increase the pH.
    Can you list a few that you think are most effective?

    Thank you in advance

    em88 replied 6 years, 10 months ago 7 Members · 28 Replies
  • 28 Replies
  • ZivBA

    Member
    June 7, 2017 at 8:12 am

    To increase the pH:

    TEA, NaOH, Cocamide DEA, Cocamide MEA.

  • em88

    Member
    June 7, 2017 at 8:41 am

    Thank you very much for your reply! 
    I’ve used TEA, and added about 2% to increase the pH from 4 to 5 and wired thing was that it decreased the viscosity of the shampoo a lot.
    I was thinking about NaOH as well, but at what molarity should the solution be? 

  • charmer

    Member
    June 7, 2017 at 8:53 am

    10%

  • em88

    Member
    June 7, 2017 at 8:54 am

    Thanks. Will try it! 

  • em88

    Member
    June 7, 2017 at 10:25 am

    Ok, I tried using NaOH 10% and I added to one test probe ~ 6 % (pH 3.9 -> 5.14)
    and to an other test probe ~2 % (pH 5.05 ->5.8). The second probe had already TEA which increased pH from 4 to 5.
    NaOH decreased the viscosity of the shampoo as well (it seemed that it decreased it a little less than TEA)
    Will have to make a few more tests to get a better comparison for TEA and NaOH and determine which one is more suitable since the two tests I did were not similar in the start. 
    Anyone else had similar experience with shampoos?

  • johnb

    Member
    June 7, 2017 at 10:29 am

    It might be wise to investigate why the pH of your shampoo is so low.

  • em88

    Member
    June 7, 2017 at 10:42 am

    That is because of the API which is salicylic acid

  • johnb

    Member
    June 7, 2017 at 12:34 pm

    Neutralised salicylic acid has little or no dermatological activity.

  • em88

    Member
    June 7, 2017 at 12:48 pm

    So what should I do? Leave the pH 4? 

  • johnb

    Member
    June 7, 2017 at 1:08 pm

    I recall having similar discussions re salicylic acid with you previously.

    If you want an anti-dandruff/antiseborrhoeic activity then, yes the free acid is necessary.

    There are a number of less aggressive and more up-to-date materials you could use which have A/D//A/S activity.

    Depending on where you are located, you may need to register your product as a drug or medicine.

  • em88

    Member
    June 7, 2017 at 1:32 pm

    Indeed we had a discussion regarding SA
    In this case the SA is at 3% which can be considered as cosmetic if specified as rinse of. The original shampoo product i’m trying to make the generic, has the pH 5.15
    The shampoo is going to be for psoriasis (and seborrhoeic, dermatitis)
    I am currently reading some patents about pH interval for shampoos and it seems that pH 4 is ok for the scalp. 

  • belassi

    Member
    June 7, 2017 at 3:37 pm

    The reason the viscosity changes is simple, you are adding ionic compounds to the shampoo.

  • johnb

    Member
    June 8, 2017 at 7:36 am

    You state that you regard your product as a cosmetic yet you also state it is for psoriasis and seborrhoeic dermatitis- presumably this means the treatment of these conditions. This fact makes makes your product a medicine irrespective of the concentration of any API.

  • em88

    Member
    June 8, 2017 at 10:50 am

    That is not a problem at all. As stated in our previews conversation, I have only mention where the project is targeted not how it will be described for.
    There are lots of plant teas that are targeted for specific diseases, it doesn’t mean they are medicine drugs. Anyway, it would be better to focus more in the technical/chemical issues.

  • em88

    Member
    June 8, 2017 at 10:50 am

    Belassi Thank you.

  • belassi

    Member
    June 8, 2017 at 4:45 pm

    Note that ANY time you adjust pH for a shampoo that relies on salt-curve thickening, you will get a viscosity change. When you adjust pH you’re adding either negative or positive ionic compounds - for example citric acid will react to form citrates, which are salts, and alter the salt curve. 

  • em88

    Member
    June 9, 2017 at 8:14 am

    Thank you for your time Belassi.
    I red about salts and salt curve that increases the viscosity of shampoos. 
    I’m waiting for an other substance that I should add in the shampoo which has a pH 5-6 in 10% water solution and I’m guessing the viscosity should change. 
    It will be a “watching and learning” experience. 

  • NoHypeCosmetics

    Member
    June 10, 2017 at 3:20 am

    Aloe vera gel that is 5-7 ph and is water based with thickening agent not medicinal but fyi very gentle for “sensitive” skin misfortune.
    nohypecosmetics.com.

  • em88

    Member
    June 20, 2017 at 11:42 am

    Quick question:
    Are there limits in adding NaCl for viscosity adjuster? 
    From what I red NaCl at 3.5% will dry the skin and hair. 
    I did the salt curve and if I go over 2% (say 2.5%) the viscosity still increases. 

  • DRBOB@VERDIENT.BIZ

    Member
    June 20, 2017 at 5:31 pm

    adding too much salt is like washing your hair with salt water and dries hair and skin::I would not exceed 1.5% NaCl

  • belassi

    Member
    June 20, 2017 at 7:35 pm

    Without knowing your ingredients list it is not possible to help further.

  • em88

    Member
    June 22, 2017 at 12:12 pm

    @DRBOB@VERDIENT.BIZ, I’m adding 1.5% NaCl and I’m getting the viscosity in the range of 2900-4000 cP.
    @Belassi, I’ll add the ingredients shortly.

    One more question, I was looking the the shampoo that I am trying to make a similar one, and I noticed they have add Sodium Citrate (it seems a lot actually since it is in the top of the ingredient’s list). What is the purpose of it? Adjusting pH or viscosity?
    Original shampoo ingredients

    Original shampoo ingredients:
    Purified water, ammonium lauryl sulfate, sodium laureth sulfate, sodium citrate, cocamidopropyl betaine, lauryl glucoside, PEG-150 pentaerythrityl tetrastearate, coco-glucoside, glyceryl oleate, aleurites moluccana seed oil, zinc PCA, panthenol, rheum palmatum extract, carthamus tinctorius (safflower) flower extract, camellia sinensis leaf extract, edetate disodium

    Thank you

  • belassi

    Member
    June 22, 2017 at 5:34 pm

    Why are you mixing ALS and SLES? ALES is readily available and works far better than SLES which is a crummy surfactant in my opinion. Did you get this from a commercial product (it sounds as if you did because two of the ingredients together = Lamesoft PO65)
    Sodium citrate is probably listed but not added as such, more likely to be the final product of adding citric acid.

  • em88

    Member
    June 23, 2017 at 9:15 am

    Hello,
    That is from inspiration product.
    The ingredients I am using are: 

    Sodium Laureth Sulfate, Cocamidopropyl Betaine, Disodium Laureth Sulfosuccinate, Hydroxyethylcellulose, Butylated Hydroxyanisole, TEA, NaCl

    Thank you

  • DRBOB@VERDIENT.BIZ

    Member
    June 25, 2017 at 9:52 pm

    Based on formula you show should be ok as sulffosuccinate will provide creamy lather.You just need a preservative (1percent phenoxyethanol).Also watch viscosity in storage as the sulfocuccinate can be thixotropic (viscosity increase with time)

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