How to dissolve Salicylic acid or AHA acid in oil?

How do I dilute salicylic acid/aha acid/or any acid for that matter in an oil? What is the min/max amount recommended? What would I use as an emulsifier? Is water added?

Thanks in advance :) 

Comments

  • These materials are not to be treated lightly and misuse can result in devastating and dangerous effects on the skin.

    The fact that you have asked the question indicates, to me at least, that you do not have the necessary knowledge and experience to use them in formulating cosmetic products.
  • I do not---which is why I asked the question.
  • johnbjohnb Member
    edited September 2016
    There are courses offered by the owner of this group which may be of use to you - see http://chemistscorner.com/members/

    I still feel that I should warn you against working with potentially dangerous materials at this stage.

  • MicroformulationMicroformulation Member, Professional Chemist
    Time to hire a Consultant if that is a product you want to make. It does rightfully requires knowing the Fundamentals.
    markfuller@microformulation.com Microformulation.com Microformulation Cosmetic Consulting provides Custom Formulations for both large Commercial accounts as well as smaller entrepreneurs. We can provide Naturally compliant Formulations under the NSF, NPA, Whole Foods and USDA Organic Certifications.
  • I agree. I wouldnt even touch them if I were you until you know what you are doing. 
  • MicroformulationMicroformulation Member, Professional Chemist
    Let me explain the hoopla for you so you can see why so many are urging caution.

    Firstly we have the solubility issues. AHA's are generally water soluble not water soluble. Salicyclic acid is only soluble in very specific organic solvents for the most part and even this takes some knowledge in the selection of the solvent and the process in which to dissolve the SA in these solvents in a stable manner.

    Next is the question with the min/max levels. Minimum levels are essentially zero. Minimal therapeutic levels vary a great deal from AHA to AHA. Remember the term AHA describes a group of compounds with differing properties. SO the question (simply due to its vagueness) is difficult to answer. AHA's can be dissolved at high levels, in fact at levels far above the safety limits. In general, the Cosmetic Ingredient Review (a great source of the safety of Cosmetic raw materials) recommends no more than 10% AHA's and not less than a 3.5 pH. This pH would need to be accurately measured with a meter, not strips.
    Salicylic acid is even more regulated as it is an OTC ingredient. The allowable percentage for it's use in acne is delineated in the FDA Acne monograph. It also has been used in peels and wart products, but at extremely high levels, a Formulation that requires great care and knowledge.

    Lastly we have the labeling and after use safety issues. The AHA's require a sunscreen warning and the exact verbiage can be found in multiple sources. The regulatory and labeling requirements are found in the OTC monograph.

    It should shortly become apparent that this is not a simple, innocuous DIY product. It will require knowledge, equipment, special solvents and great care.

    I will close with an additional glimpse of why many also recoil at these products being approached in a cavalier manner. The DIY movement is strong in Cosmetics but there must be a clear line delineating what is appropriate for this sector. In many cases people will have more reluctance in exploring how to repair their vehicle over the internet than they would in doing such a potentially dangerous product. Let me be clear and say that I don't know your background and I am not labeling you as a DIY'er. It is a blanket statement. Even someone with formal training and the proper support would put in extensive research before attempting this type product.
    markfuller@microformulation.com Microformulation.com Microformulation Cosmetic Consulting provides Custom Formulations for both large Commercial accounts as well as smaller entrepreneurs. We can provide Naturally compliant Formulations under the NSF, NPA, Whole Foods and USDA Organic Certifications.
  • My personal view is that I leave this kind of product to big companies. Why? Because they can afford the legal costs if/when they get sued.
    Cosmetic Brand Creation. Concept to name to IMPI search to logo and brand registration. In-house graphic design inc. Pantone specs. Cosmetic label and box design & graphics.
  • TonyTony Member
    Salicylic acid dissolves well in vegetable oils, provided you heat the oil a little bit, for example in a water bath (bain-marie). I'm using a lotion with 1/2 olive oil and 1/2 cold pressed citrus peel oils (1/6 mandarin, 1/6 lemon, 1/6 bergamot) with 1 % salicylic acid added. The salicylic acid dissolves well under heat, the citrus oils probably act as an additional emulsifier, other than those already contained in olive oil.

    This is for combating infected calluses owergrown by dermatophytes, with moderate hyperkeratosis. The oil is very effective in controlling the infection, but the hyperkeratosis needs a bit more salicylic acid (I guess 2-3 %). 1 % is already quite effective, however, especially if you apply it over a longer period. I didn't try water-based peelings, but anything water-based, like urea, makes the fungus grow wild. Therefore I'm probably better off with an oil based solution. Luckily, I have no adverse skin reactions to the essential oils.

    For comparison, Whitfield's ointment uses 3 % salicylic acid and 6 % benzoic acid in petrolatum or lanolin. OTC peeling preparations in Germany ("Salicyl-Vaseline") contain 10 % salicylic acid in petrolatum.


  • DoreenDoreen Member
    @Tony
    This is a very old thread!
  • GuntherGunther Member
    edited May 2018
    Please be aware that SA solubility varies depending on the oil used
    i.e. much more soluble in castor oil than olive oil.

    For example read the study
    STUDIES ON OINTMENTS
    II. OINTMENTS CONTAINING SALICYLIC ACID

    One part of salicylic acid dissolves in 13 parts of boiling water, in 444 parts of water at a temperature of 15 C., in 500 parts of water at 20 C., in 60 parts of glycerin, in 45 parts of olive oil and in 7 parts of castor oil.
  • What about using a powdered version and adding it at the end of an emulsion, if that was what you were making? You could use Lactic Acid as well, good for moisturizing and/or deep cleansing.
    If you need any more help with that I am only an email away at drclambert@hotmail.com
    Good Luck
    Dr. Catherine Pratt
    (B.Sc with HONS I , Ph.D Analytical/Organic Chem and Microbiology), Cosmetic Chemistry IPCS)
  • AHA and BHA acids: Look at pKa value for selected acid. The pH = pKa, it's 50/50: 50% free acid and 50% ionized. The free acid will absorbed through skin. The ionized acids will not absorbed through skin. But, the portion of ionized acids on the skin will become free acid. Then, it absorbed through skin, very slowly.
    For AHA, the best performance is pH=4 with concentration less than 10% .
    For BHA, the best performance is pH=3.5 with concentration  1 - 2%

    To calculate the weight required for AHA/BHA:
    I use c1v1 = c2v2


  • liprepap said:
    How do I dilute salicylic acid/aha acid/or any acid for that matter in an oil? What is the min/max amount recom and have had no imended? What would I use as an emulsifier? Is water added?

    Thanks in advance :) 
    it depends on the concentration of the SA if its a powder. When it comes to formulating with SA. Many people are scared to formulate with this acid and there is nothing to be scared about if you research and know how to use it properly and the proper %. Salicylic acid can be dissolved in propylene Glycol and propanediol 1,3, also it is oil soluble. I make all my own AHA and BHA products and have no issues. I use a 88% lactic concentration and a 99.8% Glycolic concentration. The  SA is should be used at a 2% in skin products like face lotions, etc. the AHA's very due to skin type and toleration. Most are 8-10%. 10% is usually used for beginners and al the way up to 70% in a professional medical office. Please just do lots of research on ALL AHA's and BHA's before formulating with them for your cosmetics and personal use and always do a skin patch test before using a full application. I have also used Vodka to Dissolve my SA and worked just fine 76& Vodka. Do not be afraid to experiment with AHA's due to others fears. Research will provide you with the correct information that you need. See attached docs for solubility.

  • MicroformulationMicroformulation Member, Professional Chemist
    The 10% AHA's are not for "beginners" but rather the safety protocol's addressed by the CIR. AHA Peels with higher levels are "Professional Products" Only.
    markfuller@microformulation.com Microformulation.com Microformulation Cosmetic Consulting provides Custom Formulations for both large Commercial accounts as well as smaller entrepreneurs. We can provide Naturally compliant Formulations under the NSF, NPA, Whole Foods and USDA Organic Certifications.
  • I don’t know what to say here... I have experience with over 100 ingredients (oils and esters excuded) and already experimenting with water in oil which isn’t for beginners but I don’t think I am experienced enough to mess with AHAs. It’s not a good idea to encourage someone  to make 10% toners at home. Products with concentration over 30% can only be used at dermatologist’s office.
  • I have done all my research and have already made my AHA moisturizer and Glycolic peel. I have the same concentration as mentioned earlier. 88% Lactic and 99.8% Glycolic crystals. The SA is powder form and did dissolve using the PG and the propanediol 1,3. Thank you for all your help and I did my own testing (skin patch testing) for all my formulas and found that the 10% was perfect for a very light , however I would not recommend anyone using this % on their own either as everyone has different skin type and tolerance and this just worked for me. As for the SA I am going to be making a gel in a 2% formula and I will see how this does on my skin for a leave on. As always researching and testing is always the best, maybe not the fastest that we would like but deff the most beneficial and safest...
  • What about using a powdered version and adding it at the end of an emulsion, if that was what you were making? You could use Lactic Acid as well, good for moisturizing and/or deep cleansing.
    If you need any more help with that I am only an email away at drclambert@hotmail.com
    Good Luck

    I Thank you kindly as that is exactly what I ended up doing. I have the aqueous Lactic Acid 88% concentration. I absolutely love the moisturizer that I made...
  • @Jdawgswife76 that is fantastic, sounds like you are enjoying yourself! and that is what its all about!
    Thank you for the kind words...
    Dr. Catherine Pratt
    (B.Sc with HONS I , Ph.D Analytical/Organic Chem and Microbiology), Cosmetic Chemistry IPCS)
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