Home Cosmetic Science Talk Formulating Soap transparency issues with acids

  • Soap transparency issues with acids

    Posted by Den_Ai_D on July 25, 2019 at 2:41 am

    I’ve recently encountered transparent soaps with salicylic & glycolic acid and wanted to try making something akin to them myself. As a trial, I tried mixing said acids on their own with a transparent, melt & pour soap base as in the following formula:

    Soap base - q.s.
    Salicylic acid - 0.5%
    Propylene glycol - 3%

    Soap base  - q.s.
    Glycolic acid - 0.5%
    Aqua - 1%

    The acids were dissolved in propylene glycol and water respectively before addition to the molten soap base at 70C as I didn’t feel confident in just chucking them in undissolved. 

    Issue arises upon cooling, where both become opaque/incredibly hazy. So, any ideas why this might be happening and how to prevent the opacity? I’m fairly new to formulating so any inputs will be really appreciated. Thanks.

    Den_Ai_D replied 5 years, 5 months ago 2 Members · 2 Replies
  • 2 Replies
  • ozgirl

    Member
    July 25, 2019 at 5:42 am
    You will need to provide a list of ingredients for your soap base to get any real answers but you are probably destroying some of your soap based ingredients by acidifying them. Generally speaking soap + acid is not recommended as it reverses the saponification reaction.
    Perhaps the transparent soaps you saw were actually syndet bars.
  • Den_Ai_D

    Member
    July 25, 2019 at 7:20 am

    ozgirl said:

    You will need to provide a list of ingredients for your soap base to get any real answers… 

    Oh sorry, I should’ve added it in the first place. They are: water, sodium plamitate, sodium palm kernelate, propylene glycol, glycerin, sucrose, sorbitol.

    Thanks for the reply! I may just look into syndet bars if this proves to be a dead end. 

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