Home Cosmetic Science Talk Formulating Adding salicylic acid to lotion

  • Adding salicylic acid to lotion

    Posted by abdullah on December 1, 2020 at 2:34 pm

    I have a small sample of salicylic acid so don’t want to waste it buy Making several trail sample batchs and need your help before starting.

    How to add %1 or %2 salicylic acid to this lotion?
    Do i need any solvent?

    Olive oil   %6
    Petrolatum   %4
    Glyceryl caprylate %0.7
    Polyglyceryl-4 Laurate %4
    Glyceryl oleate %2.5
    Ethyl Lauroyl Arginate HCl  %0.2
    Essential oil %0.5
    Sodium phytate %0.1
    Citric acid 
    Water 

    Ph 5

    microformulation replied 3 years, 3 months ago 5 Members · 18 Replies
  • 18 Replies
  • markbroussard

    Member
    December 2, 2020 at 3:26 am

    I would recommend that you dissolve the SA in the oil phase when you heat to 70C prior to combining the phases to form the emulsion.

  • Cst4Ms4Tmps4

    Member
    December 12, 2020 at 8:10 am
    Weird. At pH 5 Salicylic Acid should be fine.
    Since I ‘wasted’ lots of materials in my tests, I can ‘save’ you some money. :D
    There are two surest way to dissolve or solubilise Salicylic Acid.
    1) Lots of Propylene Glycol and some nonionic surfactant (I use PEG-40 Hydrogenated Castor Oil. Polysorbate 80 also works). I do not think this can be added to anything as it may recrystallise. I don’t know for sure as I do not mix it with anything else.
    2) After I got fed up using crazy much Propylene Glycol as in point (1), I followed what @MarkBroussard mentioned in this site with a twist. Instead of using Sodium Citrate, I add Sodium Bicarbonate. This actually neutralises some Salicylic Acid forming Sodium Salicylate. Make it pH 3 to pH 4. Oh my, this works wonderfully! You can actually judge it by its turbidity (no need keep checking pH like a fool).
    But the trick is you really need to make Salicylic Acid crystals extremely small to work well. Meaning, dissolve it in Propylene Glycol and nonionic surfactant, with heat. I do not think this is called solvation as it is not a salt. More like a suspension. Identical to oil in water is not truly dissolved in water in the presence of surfactant, the oil is still there and exist in tiny droplets which are being suspended in water.
    Next, is to add some water to the SA-PG-nonionic sufactant solution and then neutralise it. Look at the colour change. Ah, chemistry is fun! My friends always say that I make things look like semen (white but not very white, and slimy). I do not work with so-called “high-tech” stuff promoted by marketing. I make functional stuff, not beautiful stuff.
    You could try making it without Propylene Glycol or nonionic surfactant or neutralisation. I have no luck with either one if they are singled out, or either one is taken out.
    If Polysorbate 80 is used I think you can see Salicylic Acid in the form of oil droplets in water! Amazing! I prefer using PEG-40 HCO because I do not need to use it as much as Polysorbate 80. Maybe many extra two lipophilic tails in PEG-40 HCO compared to Polysorbate 80.
    Oh one more thing is I increase the suspension power by adding Xanthan Gum. This is my ‘perfect’ SA solution! It definition is not as potent as very acidic one but it does really work and I can feel my skin is dry. Excellent for my greasy and acneic skin. Really Sciencesend. Not madly irritating compared to very acidic one.
  • abdullah

    Member
    December 13, 2020 at 3:07 am

    @MarkBroussard thanks 

    I did add %1 salicylic acid to oil phase and added oil phase to water. Then adjusted the pH with sodium hydroxide%30. It is stable until now. 

    Questions:
    1. Can i adjust the pH of salicylic acid in oil phase or befor adding it to oil phase before making the emulsion? 

    2. In how many days usually crystalization of salicylic happes as my lotion is stable until now?

    3. If crystalization happens, does it destabilize the emulsion?

  • abdullah

    Member
    December 13, 2020 at 3:20 am

    @Cst4Ms4Tmps4 thanks 

    I am using olive oil, petrolatum and non-ionic surfactant Polyglyceryl-4 Laurate. I don’t have those non-ionic surfactants you said available. Is it enough?

    How to make Salicylic Acid crystals extremely small? By homogenizer or there is another way? 

    Can i neutralize salicylic acid with sodium hydroxide to make sodium salicylate? 

    Does sodium salicylate have the same anti acne and exfoliating effects as salicylic acid? If yes can i use sodium salicylate instead of salicylic acid for these purposes?

  • Cst4Ms4Tmps4

    Member
    December 13, 2020 at 5:02 pm
    Oh yes you asked about Sodium Salicylate in another post which no one responds to. This Salicylic Acid topic is super sensitive. LOL!
    There is one study which says nearly fully neutralised Salicylic Acid works the same as acidic one, although a little slower than acid one.

    Personally, even at pH 3 it does not peel my skin. Please do not take what I said as fact because maybe my top most layer of skin is already peeled when I was experimenting with 2% SA in Ethanol-Water (My very first test after a very long time of not using Salicylic Acid in any forms). This works beautifully but the next time I used it it is the Ethanol which stings me like no body’s business because the top most skin is already off. It does take some time for the analgesic effect to kick in.
    At that point even a little alcohol stings. So, I went on to making a non-alcoholic a bit neutralised (≈ pH 3) Salicylic Acid solution as mentioned before. But I increased the amount of Salicylic Acid to 5%.
    Not much peeling is observed but it appears that acne is somehow controlled, skin is more dry than before which is a good sign that it may be working. I use the solution three times a day, every day. It takes not much money to make it so I can afford to slap it thickly on my face. “Maskne” ruined my pretty face since COVID started, hence I have no problem ruining my face some more with SA.
    Oh, physical scrubbing is still essential! Without physical scrubbing the ‘dead skin’ will pile up and itches you. Urm…I do not know about you but it happens to me far too many times. Your mileage may vary.
    Chemical exfoliation per se is not enough for me. Without physical exfoliation my skin is more and more rough, more and more greasy, more and more itch. Dead skin probably hold too much oil and therefore causes itch. As soon as I scrub it…aaaaaahhh I can see and feel the difference!
  • Cst4Ms4Tmps4

    Member
    December 13, 2020 at 7:31 pm
    Oops. I forgot about another two questions of yours.
    Solubiliser + Surfactant + Heat + Thickener = Salicylic Acid crystals very small, suspended, stable. No need for homogeniser or sonicator.
    I have no luck mixing Salicylic Acid in oil or Petroleum Jelly. Maybe I have not used enough high. I am not interested in oily stuff to do more test.
    From what I understood it is not soluble in many things including all kinds of oils (mineral oil, vegetable oil) and Petroleum Jelly. Rather it is being suspended in oils.
    Yes. You can use Sodium Hydroxide to make Sodium Salicylate.
    1. Can i adjust the pH of salicylic acid in oil phase or befor adding it to oil phase before making the emulsion?
    Try as you might but it is impossible to neutralise it in oil phase! It has to have water. Vehicle without water (e.g., Petroleum Jelly) has no pH.
    Maybe you could do it as you use Sodium Hydroxide which I assume is already mixed with water. You can do it if there is water…so yes before and after probably makes no difference.
    2. In how many days usually crystalization of salicylic happes as my lotion is stable until now?
    Only ‘God’ can answer! LMAO!
    This is an impossible question to be answered! YOU have to be the judge. It is not a mathematical question. There are too many variables. I never see mine recrystallise for many months, it may recrystallise on you in days. Some people found that it recrystallises the second day.
    If you have lots of solubiliser, surfactant, etc, etc, then very unlikely that it will crystallise even if the temperature is low. I am pretty heavy-handed with those stuff.
    3. If crystalization happens, does it destabilize the emulsion?

    Yes if you use chemicals that are pH-sensitive. Many thickeners are sensitive to low pH. Carbomer is the most sensitive. Even if you neutralise Salicylic Acid effectively making it salt (i.e., Sodium Salicylate) Carbomer instantly ‘melts’ in the presence of salts as it is extremely sensitive to electrolytes.

    Some emulsifiers will ‘curdle’ in low pH. The name is something ‘mono-diglyceride’ something. I tried only few times and I dropped it. Pointless. It needs some other surfactant to work in tandem. Something to do with HLB. Also, there are many grades of that thing (It is not a pure thing. It is a mixture of something something in different ratios which complicate things). Too much work for my tiny brain.

    Actually, it does not need to crystallise to destabilise the emulsion. It is the pH.

  • abdullah

    Member
    December 14, 2020 at 3:24 am

    @Cst4Ms4Tmps4 thanks. Very helpful.

    If i want to neutralize salicylic acid with sodium hydroxide to make sodium salicylate, should i just add and mix sodium hydroxide%30 to salicylic acid until the pH is around 6.5 or it has a specific way? 

    Will neutralization of 10g salicylic acid give 10g sodium salicylate or a different quantity? 

  • Cst4Ms4Tmps4

    Member
    December 14, 2020 at 4:11 pm
    You are welcome.
    Will neutralization of 10g salicylic acid give 10g sodium salicylate or a different quantity? 
    Err…wait a minute….what…..
    I do not want to sound insulting but do you have some chemistry basics? Science?
    I am afraid of going deeper into hell for sharing too much with you.  Hahahahaha!
    And since this Salicylic Acid thing has been a highly sensitive topic in this site and at the same time becoming a hot topic of late. I think due to COVID.
    I love sharing and this community is about sharing. But looking at the trend the experts are avoiding the topic like the plague, it is wise that I follow the trend. I dislike being a sheeple but I do not want to be sued or get into unnecessary trouble, especially when I have my actual photo displayed. I also do not want to get this site into preventable troubles.
    After looking through your posts, I have an impression that you are trying many stuff and just starting out. You do have crazy many chemicals!
  • abdullah

    Member
    December 16, 2020 at 3:34 am

    @Cst4Ms4Tmps4 hahaha 

    I was the most intelligent student in school and university. I am a Bachelor in Business Administration. I had allergy with Shampoo and i didn’t know why. I was washing my hair with a type of clay people used locally. Then after some searching on internet i thought it is sulfate surfactants that i am allergic to. I used APGs, the allergy was gone but it was not good. After valuable advises from Perry and other wise people here i made Shampoo with SLES and it was so good (better than all other Shampoos in our market) that our relatives also started using my Shampoo. Then i thought about selling it and starting a business of it. 

    Now i am looking to make other skincare products too. Currently working on lotion. 

  • abdullah

    Member
    December 16, 2020 at 3:45 am

    @Cst4Ms4Tmps4 
    I did a post about non-ionic stabilizer and thickner for water phase but no one has said anything. Do you have any suggestions? 

  • Cst4Ms4Tmps4

    Member
    December 16, 2020 at 8:36 am
    Urm….what…LOL! I am a little confused now. I am cracking my head wondering why there is a need for you to mention that you were the most intelligent student in school and university.
    Since you were the most intelligent student in school and university then I bet you can figure everything out on your own!  ;)
    I was not and I am still not as intelligent as you are, therefore I better not say anymore lest I humiliate myself with my own stupidity! :D
  • abdullah

    Member
    December 16, 2020 at 12:49 pm

    @Cst4Ms4Tmps4 hahaha. 
    I said that because it is easier to teach something to an intelligent guy 🤣.
    If you teach me one good thing then you are my teacher. I have learned many things from you so i respect you as my teacher. 

  • markbroussard

    Member
    December 16, 2020 at 2:33 pm

    Abdullah said:

    @MarkBroussard thanks 

    I did add %1 salicylic acid to oil phase and added oil phase to water. Then adjusted the pH with sodium hydroxide%30. It is stable until now. 

    Questions:
    1. Can i adjust the pH of salicylic acid in oil phase or befor adding it to oil phase before making the emulsion?

    No, make the pH adjustment after formation of the cream 

    2. In how many days usually crystalization of salicylic happes as my lotion is stable until now?

    You should not get any recrystallization

    3. If crystalization happens, does it destabilize the emulsion?

    No, the emulsion should remain stable, you’ll just have a grainy skin sensorial if you do get some recrystallizaiton of the SA

     

  • abdullah

    Member
    December 17, 2020 at 2:37 am

    @MarkBroussard thanks a lot

  • Cst4Ms4Tmps4

    Member
    December 17, 2020 at 4:35 am
    You joined only for 15 months but already have 71 questions. All of which are already answered previously. I assume you never bother using the search function.
    You even repeat the same question. Some are questioned differently but still the same content. Example how to dissolve 70% SLES.
    You even ask odd questions. I mean, you said you already did/doing something and you still ask people to know the result. You should know the result if you did it or are doing it. Example you mentioned I use Stearamidopropyl Dimethylamine %1″ and in the same breath you asked “How does it effect foam?”. I was like WHAT THE FAAAK THIS PERSON DID IT OR NOT! It is like saying I already jumped from the 10th floor and died, and then I asked you whether will I die or not. If I am still alive to ask you that it can only mean I never jump. Not even Schrodinger cat.
    Another strange one is you said “If we add in high quantity cost will increase a lot” and then “If we add in small quantity how would foam compare to above surfactants?”. Another WTF moment for me. That means you never even do it to see it/compare foam. All you love doing is ask and ask. You fundamentally never try before you ask. Very cunning of you!
    I joined only for 20 months but I posted only 3 questions. I am not as intelligent as you are. What I do is I use the search function, use YouTube, use the Internet a whole, and above all I do lots of tests and observations.
  • abdullah

    Member
    December 17, 2020 at 6:13 am

    @Cst4Ms4Tmps4 

    I Will answer all your questions that has confused you about me. 
    1. A lot of things we know may not be correct. Only by asking and confirmation from someone who knows more than us we can confirm our information is correct.
    2. Some questions are not answered or answered but I can’t understand it correctly or i can not do what they have said to do so i try to ask it again and differently.
    3. When i do add an ingredient but can’t feel any difference i ask the experts here to make sure if it really have any effect or i am just wasting it hoping it will have an effect. For example evey one says CAPB increase the foam and mildness of SLES but i can’t feel the extra foam or mildness so i ask here to make sure it really has an effect although I can’t feel it. Or SAPDMA i added it in Shampoo at different quantities but couldn’t see any difference or benefit in foam or conditioning so i asked here to make sure if it really has any benefit or the supplier claim are false.
    3. I try what ever i ask here. Some before and some after asking. 
    Some questions are to know what should i do. Some questions are to confirm what i am doing is correct and not dangerous. For example about making sodium salicylate from salicylic acid. I did make lotion with %1 salicylic acid as mark said. I then did add sodium hydroxide to salicylic acid to make sodium salicylate. About 10g salicylic acid, 3g sodium hydroxide and 10g water. The salicylic acid was completely solubilized in water. I make lotion with it at %2 and the felling was better and less stinging than %1 salicylic acid. I then asked you to make sure what i did was correct and to make sure if neutralization of 1g salicylic acid gives 1g sodium salicylate. But you didn’t say anything about that. So i may need to ask a question about that to confirm what is in my mind is correct. 
    And by the way my English is not very good, most of words are outo corrected by mobile keyboard here. So that my also have caused to don’t get the correct idea from what someone has said and i asked it again 😸
    Hope your misunderstandings about me is solved 😃
  • smok

    Member
    December 17, 2020 at 12:46 pm

    You joined only for 15 months but already have 71 questions. All of which are already answered previously. I assume you never bother using the search function.
    You even repeat the same question. Some are questioned differently but still the same content. Example how to dissolve 70% SLES.
    You even ask odd questions. I mean, you said you already did/doing something and you still ask people to know the result. You should know the result if you did it or are doing it. Example you mentioned I use Stearamidopropyl Dimethylamine %1″ and in the same breath you asked “How does it effect foam?”. I was like WHAT THE FAAAK THIS PERSON DID IT OR NOT! It is like saying I already jumped from the 10th floor and died, and then I asked you whether will I die or not. If I am still alive to ask you that it can only mean I never jump. Not even Schrodinger cat.
    Another strange one is you said “If we add in high quantity cost will increase a lot” and then “If we add in small quantity how would foam compare to above surfactants?”. Another WTF moment for me. That means you never even do it to see it/compare foam. All you love doing is ask and ask. You fundamentally never try before you ask. Very cunning of you!
    I joined only for 20 months but I posted only 3 questions. I am not as intelligent as you are. What I do is I use the search function, use YouTube, use the Internet a whole, and above all I do lots of tests and observations.

    are you from FBI?
    you know all thing about him
  • microformulation

    Member
    December 18, 2020 at 1:45 am
    Can we keep in mind that this is a Technical Resource and we should probably communicate accordingly?

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