Home Cosmetic Science Talk Formulating My first AHA/BHA toner bombed: Any suggestions for what I did wrong?

  • My first AHA/BHA toner bombed: Any suggestions for what I did wrong?

    Posted by suswang8 on July 6, 2021 at 11:50 pm

    Hi, all.
    Below was my recipe:

    Phase A
    Combine the glycerin, water (brewed white tea, basically), green tea extract, coffee seed extract, and sodium phytate, and then added the glycolic acid.  No issue.

    Phase B
    Heat a mixture of butylene glycol and ethanol to 65 degrees celsius and dissolve the salicylic acid in that.  No issue.

    When I added Phase B into Phase A, the result was a ruined, cloudy mess.  Phase B was around 50 degrees at this point, with Phase A around 40 degrees.  Was this likely the issue, or was it something else that I did wrong?  Thank you.

    7.20% Glycolic acid
    7.50% Ethanol
    7.50% Butylene Glycol
    2.00% salicylic acid
    2.00% glycerin
    71.10% Brewed white tea
    1.00% green tea extract
    0.50% coffee seed extract
    0.20% sodium phytate
    1.00% Preservative

    Formulator replied 3 years, 4 months ago 5 Members · 14 Replies
  • 14 Replies
  • suswang8

    Member
    July 7, 2021 at 12:23 am
    I just “re-ran” the above with just the following ingredients in Phase A (glycolic acid, water, glycerin), and with both Phases at room temperature.  Things similarly fell apart when I added Phase B to Phase A. 

  • MarkBroussard

    Member
    July 7, 2021 at 3:55 am

    @suswang8

    (1)   Are you heating your Phase A so it is at the same temperature as Phase B when you add Phase B to Phase A?

    (2)  I would prepare Phase A without the Sodium Phytate.  Heat Phase A and Phase B to the same temperature then combine Phase A and Phase B.

    (3)  Add Sodium Phytate as a pH adjuster once the combined Phase A/Phase B cools to room temperature and add QS Sodium Phytate to get the pH to 3.5 to 4.0

  • suswang8

    Member
    July 7, 2021 at 4:18 am

    Hi, @MarkBroussard.  Thank you.

    Regarding number 1, I did try it again using both Phase A and Phase B at room temperature, and the same thing happened.  (In that second trial, I was not using any sodium phytate.)  In all instances, when adding Phase B to A, it remains completely clear up to a certain point, and then after about the halfway point, if I add any more of Phase B, it starts to cloud and clump.

    Incidentally, I again re-ran things by “adding” 1% sodium citrate to Phase A (by way of adding a bit of citric acid and sodium bicarbonate into the water) before adding Phase B.  Same cloudiness/clumping.  This trial was also done will all ingredients at room temperature.  

  • suswang8

    Member
    July 7, 2021 at 4:30 am

    I just did a really simple test, with no additional ingredients and all components at room temperature:

    If I dissolve 1g of salicylic acid into 10g of ethanol, all is fine.  If I then add that to 80g of water, things become a clumpy mess.    

  • RedCoast

    Member
    July 7, 2021 at 5:45 am
    Is the tea something you brewed yourself? Or is it from a repacker?
    Try omitting the brewed tea.
  • DrJekyll

    Member
    July 7, 2021 at 10:25 am

    In addition to what RedCoast suggested you could leave the two extracts out. Just to eliminate.. You never know :)

  • Formulator

    Member
    July 7, 2021 at 12:26 pm

    @suswang8
     
    7.5% butylene glycol and 7.5% ethanol are not enough to dissolve 2% salicylic acid. That’s why salicylic acid recrystallises, when you dilute phase B with water. Keep increasing percentage of ethanol and/or butylene glycol until salicylic acid is dissolved, even after adding phase A.
    I would also suggest using distilled water instead of brewed white tea, as the latter can impact microbiological quality of your finished product.

  • suswang8

    Member
    July 7, 2021 at 1:51 pm
    Sorry — just to eliminate confusion:
    I am only using the following ingredients in my most recent test:
    Dissolve 1g of salicylic acid into 10g of ethanol, and then adding that to 80g of water.  I am not using any other ingredients (no tea, no sodium phytate, no butylene glycol.)
    @Formulator:  Thank you.  Please also see above because I seem to be having the same issue even trying to do 1% SA in 10% ethanol.  For the brewed tea, the water I used had been previously distilled, but thank you for mentioning.

  • Formulator

    Member
    July 7, 2021 at 2:18 pm

    suswang8 said:

    @Formulator:  Thank you.  Please also see above because I seem to be having the same issue even trying to do 1% SA in 10% ethanol.

    Keep increasing the percentage of ethanol until you can dissolve salicylic acid. At 10% ethanol, your solvent system is still predominantly water.

  • MarkBroussard

    Member
    July 7, 2021 at 2:57 pm

    @suswang8:

    You going to need at least 30% combined Ethanol + Butylene Glycol and heat to keep the SA in solution.  You need to heat both phases … this is highly unlikely to work at room temp.

  • suswang8

    Member
    July 8, 2021 at 2:15 pm
    Thank you, @MarkBroussard.
    -1-  Heating both phases and combining seemed to work fine for a few hours, but then overnight, I have crystallization.  I had added early into Phase A 0.45g of citric acid and 0.55g of sodium bicarbonate, which I suspected was the equivalent of adding 1g (1%) of sodium citrate, but perhaps I am incorrect? 
    -2-  For this well-known formulation below (Dr. Dennis Gross Peel Pads), what do you think they are doing to keep the SA solubolized?  Could they solely be relying on the alcohol? 
    “Water, Alcohol Denat. (SD Alcohol 40-B), Glycolic Acid, Potassium
    Hydroxide, Hamamelis Virginiana (Witch Hazel) Water, Salicylic Acid,
    Polysorbate 20, Lactic Acid, Mandelic Acid, Malic Acid, Citric Acid,
    Salix Alba (Willow) Bark Extract, Camellia Sinensis Leaf Extract,
    Achillea Millefolium Extract, Chamomilla Recutita (Matricaria) Flower
    Extract, Soy Isoflavones, Anthemis Nobilis Flower Extract, Glycerin,
    Copper PCA, Zinc PCA, Lecithin, Alcohol, Polysorbate 80, Disodium EDTA,
    Menthone Glycerin Acetal, Fragrance, Phenoxyethanol, Benzoic Acid,
    Sodium Benzoate, Potassium Sorbate”
    Thank you.

  • Formulator

    Member
    July 8, 2021 at 2:45 pm

    suswang8 said:

    -2-  For this well-known formulation below (Dr. Dennis Gross Peel Pads), what do you think they are doing to keep the SA solubolized?  Could they solely be relying on the alcohol? 
    “Water, Alcohol Denat. (SD Alcohol 40-B), Glycolic Acid, Potassium
    Hydroxide, Hamamelis Virginiana (Witch Hazel) Water, Salicylic Acid,
    Polysorbate 20, Lactic Acid, Mandelic Acid, Malic Acid, Citric Acid,
    Salix Alba (Willow) Bark Extract, Camellia Sinensis Leaf Extract,
    Achillea Millefolium Extract, Chamomilla Recutita (Matricaria) Flower
    Extract, Soy Isoflavones, Anthemis Nobilis Flower Extract, Glycerin,
    Copper PCA, Zinc PCA, Lecithin, Alcohol, Polysorbate 80, Disodium EDTA,
    Menthone Glycerin Acetal, Fragrance, Phenoxyethanol, Benzoic Acid,
    Sodium Benzoate, Potassium Sorbate”

    1) Salicylic acid is partially neutralised with potassium hydroxide, which will increase solubility in water.

    2) Quantity of salicylic acid is not disclosed, so there might be even less than 1%, which requires less ethanol to dissolve.

    You could try partially neutralising your salicylic acid with sodium bicarbonate, or some stronger base like sodium hydroxide.

  • suswang8

    Member
    July 8, 2021 at 4:54 pm
    Hi, @Formulator
    I figure they are using 1% SA and 10% alcohol, which should be enough to solubolize the SA, but I thought one still needed to add an additional component (such as sodium citrate) to prevent it from crystallizing?  Or, if the pH is high enough (e.g., >3.5), this is not necessary?  Thanks again. 
  • Formulator

    Member
    July 8, 2021 at 5:05 pm

    suswang8 said:

    Hi, @Formulator
    I figure they are using 1% SA and 10% alcohol, which should be enough to solubolize the SA, but I thought one still needed to add an additional component (such as sodium citrate) to prevent it from crystallizing?  Or, if the pH is high enough (e.g., >3.5), this is not necessary?  Thanks again. 

    In my experience you need more than 10% ethanol to dissolve 1% salicylic acid. Increasing pH will help. Around pH 3.5, there will be plenty of free acid left, that needs a solvent like ethanol or butylene glycol to properly dissolve. So I suggest using multiple strategies.

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