Home Cosmetic Science Talk Formulating Need help with finding a preservative.

  • Need help with finding a preservative.

    Posted by Anonymous on May 10, 2014 at 6:10 pm

    Hi! I am making a scalp tonic, and need a preservative that is propylene glycol free as it irritates my scalp. I would appreciate any input as I do not know much about formulating. I was going to use Leucidal Sf, but I have read that it may not be really effective. I would like to keep it as “natural” as possible, but understand that safety of using it is equally important. Also if this helps, I had some Ph strips in house that were 4.5- 9, and it did not change the color on it so I am assuming it is pH 4.5 and under. 

     Formula so far
    1 ml essential oils
    1 ml polysorbate 20
    120 ml (4 oz) distilled water
    Thank you in advance for any help! 
    cossci21 replied 9 years, 10 months ago 4 Members · 12 Replies
  • 12 Replies
  • MakingSkincare

    Member
    May 11, 2014 at 6:01 am

    There are many “natural” preservatives you can use.  See this link for reviews of many of them - http://makingskincare.com/preservatives/


    For accuracy, it is best to use weight measurements rather than volume (ml) and use % so you can see the proportions.  You may also need to increase the % of your poly 20 to solubilise the essential oils.  

    pH strips are inaccurate, I would invest in a pH meter.
  • bobzchemist

    Member
    May 11, 2014 at 8:12 pm

    When working at a small scale, you can skip the preservatives, and just keep the tonic refrigerated..

  • cossci21

    Member
    May 12, 2014 at 1:47 am

    http://www.makingcosmetics.com/Preservatives/Caprylic-Acid-Combo-p2147.html


    The link above is a natural based preservative using Propanediol instead of Propylene Glycol (natural replacement).
    They sell a 60ml size so might be suitable if you are only making small scale product, Its a US based site. 
  • microformulation

    Member
    May 12, 2014 at 11:20 am

    Making Cosmetics is simply repacking a Lincoln Fine Ingredients Preservative; Linnatural MBS-2.  http://www.lincolnfineingredients.com/products/133-Caprylic+Acid%2C+1%2C3+Propandiol+%28Natural%29%2C+Lauric+Acid%2C+Potassium+Sorbate.htm

  • Anonymous

    Guest
    May 12, 2014 at 1:52 pm

    Thank you for the responses! Bobzchemist I want to be able to travel with it, and not rely on fridge. It lasts about a month and from my limited understanding I don’t think it would last in fridge longer then a week. Please correct me if I am wrong. Cossci 21 and Microformulation I have a question. My tonic is a leave-in with the preservative you mentioned would that be an issue? I see it is suggested mainly with stuff that is to be washed off like shampoo. I read MSDS which identifies it as a (possible?) skin irritant. Now I am wondering if all preservatives have that listed on MSDS sheet. No one chimed in an opinion on Leucidal Sf. Has any one experienced it to be less than adequate?

  • MakingSkincare

    Member
    May 12, 2014 at 1:59 pm

    The link I posted above has a review of Leucidal.  But note, there’s a lot more to preservation than just adding a preservative eg reducing water activity, using packaging which minimises contamination in use, microbiological testing of raw ingredients and process water, etc and adding disodium EDTA and glycols will help. Another major factor is the amount of “bug food” etc in the formula. This often gives overlooked - I see many people putting goat’s milk, aloe vera, hydrosols, floral waters, extracts, protein, starches etc in their formulas which will really challenge the preservative system. Ultimately it’s best to get your product safety tested.

  • Anonymous

    Guest
    May 12, 2014 at 2:26 pm

    Thank you MakingSkincare. I did read that whole page and it was informative and is still an open window in my broswer. It mentions adding sodium benzoate to help with mold. Thank you for taking time to post! I understand what you are saying , that there is no easy answer to my question, and that ultimately product testing is what you suggest.

  • bobzchemist

    Member
    May 12, 2014 at 3:15 pm

    If PG irritates your scalp, you may have problems with many other chemicals as well. It’s not that I’m against preservatives, it’s just that you don’t seem to have the resources to test for skin irritation properly.

    Try aseptic packaging - these sterile transfer pipettes can be filled with hot liquid and then sealed with a candle flame to give you single-use packaging:

  • MakingSkincare

    Member
    May 12, 2014 at 3:28 pm

    That’s a great idea Bob

  • Anonymous

    Guest
    May 12, 2014 at 3:51 pm

    Thank you Bob! Never would have thought of that. Does it have to be hot liquid? I am not currently heating anything.

  • bobzchemist

    Member
    May 12, 2014 at 5:18 pm

    Boiling the water is the easiest/simplest way to make it sterile - the concept here is that a sterile product => sterile container + airtight seal does not need preservation. If you’re not going to boil, then you will have to sterilize your product, container and mixer another way. (It’s better to boil the water or product with a cover, and then allow it to cool while still covered for a bit before filling. If you are going to try filling while the liquid is still boiling hot, USE GLOVES!) (as usual, please don’t ask how I know this - I just do, ok?)

    This is only practical for home or lab, btw. It’s too labor intensive and the components cost too much for it ever to be cost-effective for production.
  • cossci21

    Member
    May 13, 2014 at 12:05 am

    Hi Urbanjunglebaby,

    from my experience most preservatives say that on the MSDS just incase someone has a reaction to it. It does have Potassium Sorbate in it which i have known some people to react on the face only but that is with a higher concentration, using it straight not in a mix.
    Thanks microformulation for the manufacturer. UrbanJB it would be a question to ask the supplier as they have emulsions listed as well…
    But Bobzchemist has the best idea for you most likely :-)

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