Home Cosmetic Science Talk Formulating Salicylic acid required contact time for exfoliation

  • Salicylic acid required contact time for exfoliation

    Posted by abdullah on July 1, 2021 at 2:52 am

    In how much contact time does salicylic acid need to do its exfoliating job? 

    Does it exfoliant the skin enough if used at %2 in cleansing Products or it should be leave on Product? 

    abdullah replied 2 years, 8 months ago 3 Members · 5 Replies
  • 5 Replies
  • chemicalmatt

    Member
    July 1, 2021 at 3:46 pm

    That is a factor of pH (and concentration too, of course). A 2.0% SalAc product at pH 2.5 will exfoliate almost immediately; same compound at pH 6.0 will take hours. The outcome will be same, just the contact time required much longer.

  • markbroussard

    Member
    July 1, 2021 at 4:15 pm

    @Abdullah:

    You’re not going to get that much SA deposition on the skin in a cleansing product.  Better to develop a good cleanser w/o SA and a companion leave-on product that contains the SA.  Although, you may want the marketing claim of SA in the cleanser … no harm done, but a cleanser will not be that effective at exfoliation.

  • abdullah

    Member
    July 1, 2021 at 4:49 pm

    @chemicalmatt @MarkBroussard thanks. 

    I am using it in a leave on product. The method is i add salicylic acid to water, add 0.29g sodium hydroxide for each gram of salicylic acid to dissolve it. When dissolved then bring the pH down to 4 with citric acid. Would dissolving salicylic acid this way be equal effective as if i dissolve it with butylene glycol and adjust the pH to 4?

  • markbroussard

    Member
    July 1, 2021 at 5:17 pm

    @Abdullah:

    You might be better off dissolving the SA in Butylene Glycol with 1% Sodium Citrate with a final pH adjustment to 3.5 to 4.0 … I think that will give you a more long-term stable solution.

  • abdullah

    Member
    July 2, 2021 at 11:26 am

    @MarkBroussard what about exfoliation powder? 

    Would there be any difference in exfoliation powder of dissolving SA in these two ways if the final pH is 4 in both ways? 

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