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Home Cosmetic Science Talk General Interpreting result from stability test

  • Interpreting result from stability test

    Posted by Anonymous on January 8, 2019 at 9:01 pm

    Sample of a face cream was created and divided into two containers for stability test, one at room temperature and one at 45oC. The one at room temperature remains unchanged after 2 months while the other one darkens in color and thickens as well. Both had PEG-80 and xanthan gum added. Does this result imply that the product will eventually darken in color and thicken up over time or will this only occur under high heat? The one that stays in room temperature is totally fine, no changes since mixing. Scent, viscosity and weight remain the same.

    Microformulation replied 4 years, 4 months ago 3 Members · 3 Replies
  • 3 Replies
  • EVchem

    January 9, 2019 at 12:35 pm

    Was there any water loss for the product that was in the 45? 

  • OldPerry

    Professional Chemist / Formulator
    January 9, 2019 at 11:23 pm

    Yes, that is the idea. Increased temperature increases the speed of chemical reactions.  But it is not an exact science and it’s possible that you won’t see those effects in the room temperature sample even after a year.  However, you should assume you will.

  • Microformulation

    Professional Chemist / Formulator
    January 10, 2019 at 12:04 am
    In my experience, this change in an organoleptic benchmark (change in color) would be a presumed failure due to an OOS result.