Home Cosmetic Science Talk Formulating Anhydrous Benzoyl Peroxide lotion? How to keep it in solution

  • Anhydrous Benzoyl Peroxide lotion? How to keep it in solution

    Posted by Zink on March 13, 2014 at 2:51 am

    So I’m contemplating formulating an anhydrous OTC Benzoyl Peroxide product (if it works well on me, I’ll consider getting my OTC-ok contract manufacturer to produce it). I remember using a horrible in terms of feel, yet extremely effective product called Benzoil back in 2007:

    10% benz peroxide
    Kiwi Seed Oil
    Hazelnut oil
    Jojoba Oil
    Of course, it separated quickly, the Benzoyl Peroxide in it was in form of coarse granules, which actually worked pretty well even though its feel was bad.
    So I think an anhydrous BP treatment could have some merit, but how would you keep the BP from separating/sedementing out from the oil?
    Microformulation replied 10 years, 4 months ago 4 Members · 6 Replies
  • 6 Replies
  • Bobzchemist

    March 13, 2014 at 9:23 am

    There are two ways to do this:

    1) Grind the Benzoyl Peroxide powder in the oil finely enough so that it doesn’t settle/sediment out until after your expiration date. The stability of this approach is greatly enhanced if your product has the semi-solid consistency of an ointment/cream. 
    2) Accept that the BP will settle out of a fluid product no matter what you do, and instead of trying to fight it, design your powder phase so that it readily re-disperses with shaking after it settles.
  • Chemist77

    March 13, 2014 at 11:18 am

    @Bobz I read somewhere that BP has to be handled carefully because of its explosive
    nature, fact or myth??

  • Zink

    March 13, 2014 at 5:08 pm

    Thanks Bob, very useful, the BP I have at hand is in a water based solution called Curoxyl 42%, so it def won’t be useful for this application, but it is explosion proof..

    So regarding 1) what grinding tool would be best for the job? Regarding BPO explosion risk there’s a interesting thread here: http://boards.straightdope.com/sdmb/showthread.php?t=455686 (a lot of misinformation though). If there are strict handling requirements I guess I’d have to get my CM to formulate samples for me.
    So I guess when you have your fine powder and you’ve not blown up, then use e.g. beeswax andor stearic acid to make a salve.
    2) Good tip! Probably easier to just make a salve in this case.

  • Zink

    March 13, 2014 at 9:40 pm

    BTW, couldn’t I just dissolve it in alkyl benzoate using a 75:25 benz/water solution as the ester would replace the water? 

  • Microformulation

    March 14, 2014 at 9:29 am

    You could try for a nonaqueous silicone base much like this article;


    As a Pharmacist and a purist, what is a salve?  I don’t believe that it is a recognized dosage form. Were you referring to an ointment?

  • Microformulation

    March 14, 2014 at 9:30 am
    Here is the definition. It is a colloquialism for an ointment not a Technical term. Sorry I jump on the work “pill” also. That isn’t recognized under USP either. It is either a tablet or a capsule and subcategories thereof.


    noun: salve; plural noun: salves
    an ointment used to promote healing of the skin or as protection.
    synonyms: ointment, cream, balm, unguent, emollient;

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