Home Cosmetic Science Talk Formulating Acid suggestions to lower a skin cream pH while avoiding the sun-sensitizing citric acid?

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  • Cst4Ms4Tmps4

    Member
    November 3, 2019 at 9:23 pm

    @ngarayeva001
    It is very soluble in water! I do not know how soluble it is but I manage to make a solution of it, 60g or 60% in water. I do not know where you live, for me is easy for it to be dissolved due to the high ‘room temperature’ here.

    Many Asians making (silken) bean curd had long replaced Citric Acid and Boric Acid with GdL. Without scientific data they learnt that it has something to do with heat. Not only it is far less sour than other acids (at the same gramme), but also makes the smoothest and most even bean curd because GdL can be properly mixed in and the soybean milk has chance to rest and stay still while proteins are being coagulated. With Citric Acid the result is nearly instantaneous regardless of temperature, bean curd like this is gritty, uneven, and if ‘unlucky’ it tends to and prone to oozing liquid (syneresis).

    I presume you tested pH while it is not completely turned to its acid form. GdL is slightly sweet! I do not mean sweet as an expression, it is truly sweet. Taste it! Very soon it turns sour. I assure you, its pH is proper low once its devilish side of metamorphosis is complete. Depending on concentration, it will start to sting your eye, wound, etc. Oh, also depends on concentration, pH is low enough to make your eyes squint and make funny faces. I guess the latter is the best evidence!   :D

  • helenhelen

    Member
    November 25, 2019 at 12:19 pm

    @Cst4Ms4Tmps4, I’m interested in your experience with Glucono Delta Lactone. Do you then ever use it in place of Citric Acid in skincare? Would it also improve the smoothness of an emulsion in the same way that it does for the bean curd?

    In heating, do you heat the GdL in water separately before adding to the rest of the formula? How hot does it need to be heated to get the nearly instantaneous acidification that you mention?

    Does the pH drift for some time after in a formulation?

    Thank you!

  • Cst4Ms4Tmps4

    Member
    November 18, 2020 at 4:13 am

    @helenhelen

    OMFAG! I missed your comment! I had not been using this site for some time.
    And there is no notification to show me who tags me and who responded to my comment/post. I need to keep the bloody tab/page open! This is the reason why I got bored of this.

    Do you then ever use it in place of Citric Acid in skincare?

    Yes, I use GdL exclusively. I hardly use Citric Acid. I never use other acids. I found that the acid form (Gluconic Acid) is way more ‘moisturising’ than Citric Acid.
    Moisturising may be a useless terminology (marketing thing). I should say ‘smooth’.

    Citric Acid tends to provide ‘rough’ feel. I presume that is crystal.

    Gluconic Acid does not seem to recrystallise, it becomes sticky instead. This may explain as to why the lack of roughness. Perhaps it was a coincidence. I am not sure; I only did the drying test only one time. I was understood that GdL is an ester. Ester tends to have ‘special properties’.

    In other words, I do not use GdL for chelating. It is for feel thing.

    Would it also improve the smoothness of an emulsion in the same way that it does for the bean curd?

    No. It does not make anything smooth like that. LMAO. It is not slippery. It is just another acid stuff.

    In heating, do you heat the GdL in water separately before adding to the rest of the formula? How hot does it need to be heated to get the nearly instantaneous acidification that you mention?

    I heat a solution and see a little water vapour or condensation on beaker wall, and that is all.
    No boiling. I have nothing against ‘destroying’ ingredients with high heat. Just that it saves my time. The process can be done easily and quickly, no good reason for me to boil it or heat it for hours on end.

    No oil phase water phase. All in one pot. Steps to adding in stuff can be at any sequence. 

    Does the pH drift for some time after in a formulation?

    Whoa, difficult to impossible question to be answered! It depends on what substances are in the mix. Also, depending on the characteristics of the substances. GdL, for instance, seems like nothing on the pH, but it becomes more and more acidic. Many people who do not know better would wonder why pH was only slightly acidic and then very acidic after a while (or quickly if they heat the solution after pH test). Some also wonder why thickened solution or gel miraculously gets destabilised (liquified) after certain minutes or hours (no heating), if they use good old Carbomer.

    I do not follow what cosmetics gurus do. I already had my fair share of being a mindless sheeple. Justified mindlessness as I was starting out so I must not recreate the wheel. First copy what others do and then modify/improve from there. This is the reason why I made a very good product suited for my skin and weather conditions. My friends are using the same thing as I use, and they said they no commercial ones is as good as mine. Not because they are my friends they lick my backside. It is the power of DIY and countless tests. I live in the tropics and most people here are ‘oily’, lots of substances used and recommended in temperate countries are too heavy or greasy for us. Skin will “sweat” and shine prematurely even if the weather is cool. (What is solid in a temperature climate is actually liquid in a tropical climate due to temperate difference. Coupled with very high relative humidity. Thus, lots of oily stuff are marvellous over there, horrible over here)

    All I need is a bit of understanding of how things works. And some experimentations, of course. Because asking people and not a single test on my side I will never experience what others are saying/doing, I will for ever be asking and guessing, and very likely be following the Dunning-Kruger graph like those natrel-oganik-eko-sustaainibel-respncible activists debating from their arse.

  • helenhelen

    Member
    November 18, 2020 at 10:46 am

    @Cst4Ms4Tmps4

    @helenhelen

    OMFAG! I missed your comment! I had not been using this site for some time.

    :D :D :D  OMG my questions were from November 2019 - the world was literally a different place back then!! Thanks so much for your answers - they are very interesting and useful.

    I do not follow what cosmetics gurus do. I already had my fair share of being a mindless sheeple. Justified mindlessness as I was starting out so I must not recreate the wheel. First copy what others do and then modify/improve from there. This is the reason why I made a very good product suited for my skin and weather conditions. My friends are using the same thing as I use, and they said they no commercial ones is as good as mine. Not because they are my friends they lick my backside. It is the power of DIY and countless tests. I live in the tropics and most people here are ‘oily’, lots of substances used and recommended in temperate countries are too heavy or greasy for us. Skin will “sweat” and shine prematurely even if the weather is cool. (What is solid in a temperature climate is actually liquid in a tropical climate due to temperate difference. Coupled with very high relative humidity. Thus, lots of oily stuff are marvellous over there, horrible over here)

    That’s a great mindset. I also believe in that. I’m currently on iteration #130 or thereabouts of one single body cream - that’s not an exaggeration. I’m in the opposite climate to you.. I’ve been working on a product for drier and dehydrated skin. Like you, people have said it works better than any commercial products. But I was never happy with the texture, smell etc.. but am getting very close now to what I had in mind.

  • Cst4Ms4Tmps4

    Member
    November 18, 2020 at 3:27 pm

    @helenhelen

    Only now I got that “1” symbol as notification!  :(
    Thankfully not another one year before I notice you wrote to me! Ha!

    I do not count how many tests I did. But I know many, many. I started this DIY stuff since 2017.

    One of my friends lives in the UK. She always complains about skin too dry. It is common over there due to low temperature and relative humidity. I sent her a sample of dreadfully rich lotion (not cream) and it was still not enough for her. I used it here and I sweat unnaturally as mentioned before. That was based on Behentrimonium Methosulphate and Behentrimonium Chloride. Archaic formulation. Hehehe. This was my earliest copy! Copied from SwiftCraftyMonkey. My first exposure to DIY stuff.

    Ah. So, you are also DIY.

    The problem with DIY is we do not always get to use “advanced” stuff. Of course money solves all problems whether DIY or not. I do not have too much money. I am not funded. I already have many useless stuff collecting dust and waiting to be thrown away.

    Useless stuff = marketing

    Generally, I wasted lots of money on marketing. I considered myself paying for a lesson, and lesson learnt!

    Since learning much from this site and people, only will I know there is so much bull and cow in this industry as any other industries in the world.
    I join gardening/horticulture/agriculture groups (research-based, of course) only from there did I know it also has full of woo-woo of its own.

  • helenhelen

    Member
    November 18, 2020 at 6:08 pm

    @Cst4Ms4Tmps4 Yes, I’ve been DIY since this year, but the crux of the formulation I’m working on is actually from a chemist I originally paid to develop something. It’s the best of both worlds - the decades of experience and know-how from a cosmetic chemist, and then the ignorant DIY dabbling without paying a chemist for every time I want to tweak the formulation or try some new wonder ingredient I just read about. After all these iterations, I have barely strayed from the original formulation, just very tiny tweaks and additions/subtractions, but all the trial and error has made a difference overall.

    I’m afraid I have also spent a lot of money on ingredients that are now collecting dust. But it’s all a learning experience! If you didn’t try it, you wouldn’t know!

    And yes, the UK winter dry air is very unforgiving!

  • suswang8

    Member
    November 22, 2020 at 8:12 pm

    Separate “citric acid” question:  Is it ever acceptable to add minute amounts (e.g., 0.05%) of citric acid during the water phase if one knows in advance that the pH will be too high?  (It seems like standard practice is to always test the pH and add citric acid during cool down.). Thank you.

  • graillotion

    Member
    November 23, 2020 at 8:10 am

    suswang8 said:

    Separate “citric acid” question:  Is it ever acceptable to add minute amounts (e.g., 0.05%) of citric acid during the water phase if one knows in advance that the pH will be too high?  (It seems like standard practice is to always test the pH and add citric acid during cool down.). Thank you.

    I do all the time….for some reason I get a little foam on my water phase….and the second I add the citric….foam is gone….love it.

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