Home Cosmetic Science Talk Formulating Product smell and viscosity changed 1 month later

  • Product smell and viscosity changed 1 month later

    Posted by esthetician922 on July 12, 2020 at 9:44 pm

    This is my formula. I loved it for the first couple of weeks and now it has a “smell” not a bad smell just as noticeably different smell, almost like vitamin E to it and it’s “sticky”. It’s been in mostly 75 degree weather. Nothing extremely hot or cold. Any ideas why it would start changing after a month? I didn’t add a preservative because the pH is at a 3. I did a microbe test when I made it. It’s in a dropper bottle. I can retest it for microbial growth if you think that’s what happened. 

    Lactic

    11.11%

    Glycerin

    2.50%

    Sodium lactate

    2.50%

    Green tea

    1.00%

    Siligex

    1.00% (Xanthan Gum, Lecithin, Sclerotium Gum, Pullulan )

    What preservative would you add if you think it needs one? 

    Pattsi replied 3 years, 10 months ago 5 Members · 5 Replies
  • 5 Replies
  • chemicalmatt

    Member
    July 13, 2020 at 9:35 pm

    Should not need one at that pH and Aw, but one of the acids e.g. benzoic, sorbic, undecylenic would be appropriate. As for the smell, lactates can smell wonky after a spell, kind of like sweat. Just a hunch, not a certainty. That green tea may not be acid stable also.

  • helenhelen

    Member
    July 13, 2020 at 9:53 pm

    Siligel is known to smell bad after a while if you don’t use a chelator and antioxidant.

  • Pharma

    Member
    July 14, 2020 at 7:43 pm
    I observed that with lecithin too (@helenhelen).
    BTW 11% lactic acid does not necessarily keep lactic acid bacteria from growing and it does not keep a bunch of yeast and fungi under control.
  • esthetician922

    Member
    July 15, 2020 at 3:03 am

    So I am new at this. At what percentages would you add what to stabilize this formula? Good to know about Siligel changing smell. Maybe I’ll just go back to xanthan gum solo. I’ll also do a microbial test to see if there’s growth now. 

    Thank you. 

  • Pattsi

    Member
    July 16, 2020 at 8:52 am

    I don’t see benefit of green tea in cosmetics other than for claim don’t know about shampoo or hair conditioner. i played with (not professional level i just play with ingredients before i go to formulators) pullulan can become sticky over time don’t know why.

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