Home Cosmetic Science Talk Formulating Skin Ethanol concentration

  • Ethanol concentration

    Posted by belassi on May 28, 2015 at 6:01 pm

    Busy formulating a product to be applied to the skin. Ethanol is the solvent of choice; assuming I make a gel using, say, a carbomer, what would be OK to use for a product that’s applied say, twice daily? Would it be OK to use say, 30% ethanol? And what carbomer would be best? I have in stock 940, Ultrez-20 and Aqua SF-1.

    Bill_Toge replied 9 years ago 4 Members · 10 Replies
  • 10 Replies
  • Chemist77

    Member
    May 28, 2015 at 7:38 pm

    I have used 940 with upto 65%% dosage for sanitizer and it holds pretty good, though I add a little glycerol to plasticize and avoid the balling of polymer in ethanol during application. With 30% you can get good viscosity of a typical gel.

  • belassi

    Member
    May 28, 2015 at 10:23 pm

    Thanks. I’ll try it.

  • Bill_Toge

    Member
    May 29, 2015 at 7:35 am

    Ultrez 20 is very tolerant of alcohol; I’ve used it with up to 60% w/w in the past, and never had any difficulties

    whichever one you use, it’s best to disperse it in the water before you add the alcohol, since it’s an absolute ball ache trying to add it afterwards
  • Chemist77

    Member
    May 29, 2015 at 10:58 am

    Yup I forgot to bring up that point @Bill_Toge, secondly it depends on budget cost as well if 940 or Ultrez.

  • belassi

    Member
    May 30, 2015 at 4:42 pm

    Will 30% ethanol be self-preserving or do I need to add a secondary preservative?

  • Chemist77

    Member
    May 31, 2015 at 1:05 am

    I suppose it must be so at 30% level.

  • DavidW

    Member
    May 31, 2015 at 3:13 am

    I believe 20% or > is supposed to be self preserving.  I personally would throw a little something in to help but as a manufacturer I do it just to have no problems.

    Carbopol 940 will work and I usually use Ultrez 21.

    Twice a day, I would think it is fine.  How many people walk around putting 62% alcohol hand gel on 3,4,5 or more times a day.  I usually throw in a decent amount of propylene glycol or glycerin or both depending on the feel the customer wants.

  • belassi

    Member
    June 5, 2015 at 11:39 pm

    Can anyone tell me, would PEG-150 work as a gelling agent with 15% ethanol?

  • DavidW

    Member
    June 12, 2015 at 12:00 am

    Not sure but I can tell you I hate the feel and consistency of PEG-150 Distearate when we use in shampoos

  • Bill_Toge

    Member
    June 12, 2015 at 6:55 am

    PEG-150 distearate is only dispersible in surfactants; don’t know what effect alcohol has on it

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