• Formulating

  Lactic Acid exfolaint

  Posted by Thota on June 14, 2018 at 6:19 pm

  I want to make a Lactic acid exfoliant at 5% AHA.
   I can get direct Lactic Acid and also Purac BF P/41. 

  Option 1
  I can use Lactic acid at 5% and then add a buffer, adjust ph to 4
  Water QS
  Aloe Vera 50%
  Lactic Acid 5% 
  Sodium Lactate (don’t know how to calculate the buffer amount)
  Adjust ph to 4 using NaOH 

  Option 2
  Water QS
  Aloe Vera 50%
  Purac BF P/41  5% 
  Adjust ph to 4  

  Questions

  1. Option 2 is easier for me as I don’t need to calculate buffer. But wondering if it gives same exfoliating effect as option 1?
  2. Also wondering in Glycerin and Propylene Glycol has any place in the above formulation as Lactic acid itself is moisturising
  3. What exactly L+ lactic acid and D - Lactic  and why is Sodium Lactate is counted as lactic acid base don ph

  Note:
  Purac BF P/41
  INCI: Potassium Lactate (and) Aqua (and) Lactic Acid Preservative-free 

  Any help,
  Much Appreciated,
  Bindu

  MarkBroussard replied 6 years, 8 months ago 2 Members · 1 Reply
• 1 Reply

• 

  MarkBroussard

  Professional Chemist / Formulator

  June 16, 2018 at 6:14 pm

  I really don’t think you need to calculate the buffering effect.  Simply add L-Lactic Acid @ 5% and use Sodium Lactate (the sodium salt of Lactic Acid) to adjust the pH to 3.85 which is the pKa of Lactic Acid.

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