Home Cosmetic Science Talk Formulating Low pH Stick Deodorant

  • Low pH Stick Deodorant

    Posted by Shiro on March 28, 2023 at 1:11 am

    I have a low pH deodorant cream that works like a dream. I would like to take it one step further and make it in stick form. My hope is for a product that glides easily without a greasy, tacky or white residue. So far the only readily available gelling agent that I have read about is sodium stearate, but its pH would be incompatible. What other gelling agent could I use?
    Something that is available at a low MOQ would be ideal since this is only for personal use.

    The cream deodorant ingredients are (in no particular order):
    Water, modified rice starch, propanediol-1,3, Lotionpro 165, triethyl citrate, triacetin, behenyl alcohol, hydrogenated ethylhexyl olivate, glycerin, sodium lactate, hydrogenated olive oil unsaponifiables, glyceryl caprylate, ethylhexylglycerin, benzyl alcohol, glyceryl undecylenate and lactic acid.
    Final product pH is 3.86.

    I would really appreciate any pointers.

    Bluebird replied 3 months, 2 weeks ago 5 Members · 27 Replies
  • 27 Replies
  • philgeis

    Member
    March 28, 2023 at 5:32 am

    Probably a better preservative capacity.

    • Shiro

      Member
      March 28, 2023 at 11:25 am

      Thank you @PhilGeis. I will consider that if making a big batch. I only make it in 100g batches for personal use, so not around long enough to cause any serious issues so far.

  • Squinny

    Member
    March 28, 2023 at 8:28 pm

    I would love to see some answers here from some of our great chemists we have on the forum. I tried to make stick type deodorants earlier on and was never successful due to making formula’s with a high pH which were ok for week or so but after that the irritation would start happening. I finally gave up and made a deo spray that I am really happy with a low pH - around 3.8. But I would like to revisit the stick do at some stage as would be better for travelling etc. So any helpful advice I’m sure there lots of us out there that would be interested. The only lame suggestions as a homemaker I can make are perhaps using beewax and adding a thickener like Cetearyl Alcohol and perhaps Kaolin Clay (no idea what this does to pH but I’m sure all the chemists know). With my Spray Deo I now use an ingredient called Cyclosorb (I buy from My Skin Recipes in Thailand even though I’m in Australia) which they have in a water soluble and cream version (I have only used the water soluble one) and it is great I can go 24 hours without reapplying - but mine is deo unscented. Anyway I hope this may be of some help. Good luck and let us know if you come up with a solution. Cheers

    • Shiro

      Member
      March 29, 2023 at 11:26 am

      I, too, am hoping that some of our more experienced chemists will share their input.
      I contemplated using cetyl alcohol, and maybe rice bran wax, but my one concern is that having that much thickener would render the product solid before the temperature cooled down enough for the cool down phase ingredients.

    • Bluebird

      Member
      June 6, 2023 at 6:55 am

      Hey, have you ever even loosely compared with and without Cyclosorb?

      Do you feel Cyclosorb adds the benefit? I’m really curious to know.

      I have had mixed feelings about cyclodextrins because on one hand they can catch odor

      but on the other hand it seems like they can “hold on to” odor longer.

      IF your spray deo was unscented, and it worked well with Cyclosorb, it sounds really promising.

  • Bluebird

    Member
    June 6, 2023 at 6:56 am

    Hey, did using lactic acid to adjust to such low pH turned out to be non-irritating?

    To your question, a lame suggestion is to look at Lume’s stick deodorant and see what they have there, since Lume’s stuff is low pH and they started from cream-based formula but ended up w/ sticks.

    • This reply was modified 3 months, 3 weeks ago by  Bluebird.
    • Graillotion

      Member
      June 6, 2023 at 3:39 pm

      The enclosed pic…Is Lume. ๐Ÿ™‚ You have seen it before.

      I tried their (Lume’s) acid….as well as a pile of others…and lactic was the nicest for sensitive skin. I should mention…for those without sensitive skin….they were fine with any of the acids I trialed.

      When Lume went from cream to stick… they went anhydrous….so a very different animal.

      • Bluebird

        Member
        June 6, 2023 at 6:37 pm

        Oh that was Lume, haha! Good to know its precise pH finally-they didn’t tell me when I asked.

        Ah so their stick was anhydrous. They do have this other clever stick-like shape that is actually creamy that comes out in a small amount if you turn the wheel so maybe that’s the alternative reference for the OP?

        Graillotion, how did you test these things (ex, sensitivity) once you made them? Did you just test on yourself and friends and family? That’s the next hurdle for me.

        • Graillotion

          Member
          June 6, 2023 at 11:13 pm

          Yes….the cream deo’s all have to have a similar delivery container. This was an early version, final viscosity was higher than shown. Mine looks like this:

          • Bluebird

            Member
            June 7, 2023 at 1:05 am

            Are things like this custom-made containers?

            I’m not gonna lie, though, this looks amazingly effective BUT a bit scary as I have a slight trypophobia (afraid of such patterns).

          • Shiro

            Member
            June 7, 2023 at 1:48 am

            How do you like the dial-up tube delivery? When I tried Drunk Elephant’s Sweet Pitti cream deo I noticed that the product that was closest to the opening would crust around the holes. For mine I use an airless pump tube and apply using my fingertips, just like I would with face cream.

            • Graillotion

              Member
              June 7, 2023 at 1:50 am

              That is a formulation issue…Not a packaging issue.

              I do not have that issue. ๐Ÿ™‚

    • Graillotion

      Member
      June 6, 2023 at 11:19 pm

      The reason Lume (IMHO) uses the acid they do…other than novel claim ingredient… is that is comes in a powder form. A non issue…for their emulsion….but pretty important in their anhydrous product…as they can suspend it.

      • Bluebird

        Member
        June 7, 2023 at 1:09 am

        What do you mean? Did you mean mandelic acid in lume is sold as powders and that’s why they use it?

        • Graillotion

          Member
          June 7, 2023 at 1:35 am

          Yes…it comes as a powder.

          I also believe they use it….because it has a nice ‘claim’ ring to it. ๐Ÿ™‚

          • This reply was modified 3 months, 3 weeks ago by  Graillotion.
          • Bluebird

            Member
            June 7, 2023 at 5:13 am

            Ah, that’s good to know, so that’s the acid that comes in a powdery form! I have been hoping something like that would exist, you know, the opposite of baking soda in terms of the pH but similarly in a powder form. I don’t get this part though (“they have a claim”)- can you explain?

    • Shiro

      Member
      June 7, 2023 at 1:32 am

      I have been using the lactic acid deo for probably one year now and no irritation whatsoever. I make it for my boss, who has extremely sensitive skin, and he has not had any issues either. It feels like a light non-greasy lotion/cream, leaves no white residue and lasts 24-36 hrs depending on level of activity.
      I got into low pH deo after using Lume and Sweet Pitti cream deos, and that’s how I arrived at the ideal pH. One thing I noticed about the mandelic acid versions was that after many months of use I would develop a slight funk/almost musty but not outright offensive, around 24hrs after use. I don’t know if that was due to the other ingredients used or the mandelic acid. So far that hasn’t been an issue using lactic acid.
      As @Graillotion mentioned Lume really changed things up on their stick version. I’m still on the hunt for the right ingredient. I will admit I got sidetracked by life a little but will be getting back on track in a few months. In the meantime I have a safari or two to distract me.

      • This reply was modified 3 months, 3 weeks ago by  Shiro.
      • Bluebird

        Member
        June 7, 2023 at 5:16 am

        I see there really are quite a few cool people on this forum and I’m delighted to find them.

        Great to know about mandelic vs lactate, hours of lasting, etc.

        The funk part gets me to think about Amazon one star reviews on Lume, which complains that Lume is effective against B.O., but on its own, it sticks and smells like B.O. when being applied. I suspect that is from mandelic acid, or possibly reaction with other things.

    • Squinny

      Member
      June 10, 2023 at 9:13 pm

      Hi sorry for late response have been on holidays! I sent you an email using the mailbox on this site if you want to discuss further happy to do so. I have found Cyclosorb to be brilliant in my spray deodorant and without it the product failed after a few hours whereas lasts for 24 hours with Cyclosorb with no underarm odour whatsoever (could be more but I shower daily! ) Cheers

      • This reply was modified 3 months, 3 weeks ago by  Squinny.
  • Graillotion

    Member
    June 7, 2023 at 1:45 am

    I have such sensitive pits….that all emollients have to be tested neat on the pits. Those that also double as a solvent…tend to irritate. When I tried Undecane (and) Tridecane, I thought I was going to have to check into a hospital burn unit!

    I did find an interesting ingredient…when I was testing emolients neat the other day… C12-13 Alkyl Lactate…tested neat….performed (odor control) as well as ANY commercial deo…I had ever tried. However…it does have a bit of a persistent chemical smell. I tried adding it at 2% to my existing formula….and it did not create any additional enhancement….but it is being added into a world class product….so I guess I could not assume it would.

    • This reply was modified 3 months, 3 weeks ago by  Graillotion.
    • Shiro

      Member
      June 7, 2023 at 1:56 am

      I have not come across C12-13 Alkyl Lactate yet. Does it have the same dry finish as C12-15 Alkyl Benzoate when used neat?

      • This reply was modified 3 months, 3 weeks ago by  Shiro.
    • Bluebird

      Member
      June 7, 2023 at 7:07 am

      What are you using this LipidSoftโ„ข Lactic for?

      You said an emollient-was moisturizing the primary purpose? If so, why not things like glycerin?

      Elsewhere I also read that this has a similar effect as lactic acid but is oil-soluble.

      Were you trying to lower pH using this in emulsified deo?

      Surprising that this was so effective as deo when applied neat.

    • Bluebird

      Member
      June 13, 2023 at 10:18 pm

      @Graillotion

      I have a new thought about the part you wrote on C12-13 Alkyl Lactate and want to hear your thought as a chemist.

      When applied neat, perhaps this ester reacts with water only on the pits->becomes carboxylic acid and ethanol via hydrolysis, and kills bacteria OR becomes ethanol and lactic acid via some bacterial enzyme and kills via lactic acid.

      But when included to only a few % of your product, perhaps just not enough in amount for that reaction,

      OR it already hydrolyzed within your product and when applied to the pits, unlike when applied neat, does not have a high local concentration of carboxylic acid and ethanol.

      • Graillotion

        Member
        June 13, 2023 at 10:28 pm

        You may have misunderstood what I implied.

        My comment was…it did not extend/enhance the performance of the existing vehicle. Therefore it was of no value to me. However…if I was starting over…and looking for candidates…it would certainly be on the ‘short list’. ๐Ÿ™‚

        It simply could not earn a spot…on an already crowded ‘team bus’.

        • This reply was modified 3 months, 2 weeks ago by  Graillotion.
        • This reply was modified 3 months, 2 weeks ago by  Graillotion.
        • Bluebird

          Member
          June 13, 2023 at 10:37 pm

          I see. What do you think of the stability of such an ester in water? I cannot say for sure.

Log in to reply.