Home Cosmetic Science Talk Formulating Advice on water-based serum with urea.

  • Advice on water-based serum with urea.

    Posted by MJL on May 17, 2019 at 2:55 pm

    Hello, 

    I want to make a water-based serum with some Urea, and need help determining the most appropriate amount of buffer to curtail pH drift caused by Urea.

    The formula would look something like this: 

    Distilled Water - % to 100
    N-Acetyl Glucosamine - 2%
    Niacinamide - 1% 
    Urea - 5% 
    Hyaluronic Acid - 0.3%
    Glucono (Delta) Lactolone - ??%
    Leucidal SF Complete - 4%

    Preferred final pH of around 5.0-5.5. Any advice on how much Glucono Lactolone I should use?

    Here is some relevant information on the Glucono Lactolone: 

    Glucono Delta Lactone [….] when added into an aqueous solution, rapidly dissolves, and slowly hydrolyzes to gluconic acid, thus producing a gentle acidification in the same way as lactic acid-producing bacteria.

    Glucono Delta Lactone, through its slow hydrolysis to gluconic acid, ensures a progressive and continuous decrease of pH to equilibrium.  So it is used as a slow release acidifier in formulations.

    pH (1% in water): 3.0 - 4.0 (gradual over 60 minutes)

    - Source: lotioncrafter.com

    chemicalmatt replied 4 years, 10 months ago 2 Members · 1 Reply
  • 1 Reply
  • chemicalmatt

    Member
    May 23, 2019 at 3:32 pm

    MJL, urea decomposition is best stabilized using a lactic acid/sodium lactate buffer system at pH< 5.5. Not sure shy you would use gluconolactone there.

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