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  • Accelerated Stability Testing Question…

    Posted by firstlight on March 21, 2019 at 2:32 am
    Hello!
    I’ve been lurking on this forum for a while and carefully read the posts so thanks for all the who add to the discussion, I’ve learned a lot.
    I’m a hobbyist and have been making my own skin care products for a few years. I recently bought an incubator so I can do some accelerated stability tests so I can gift some of my creations :)
    I starting testing the stability of a high BHA oil/water cream and within a few days in the incubator a few droplets of water have separated. Is this a bad sign or is this just condensation because the incubator is at about 38-39C, or 100-102F? Is their an acceptable amount of separation during accelerated stability tests to compensate for the high heat?
    Thank you for any help! Very much appreciated…

    rodb1958 replied 5 years ago 2 Members · 2 Replies
  • 2 Replies
  • firstlight

    Member
    March 23, 2019 at 12:47 am

    Well I emailed lotioncrafter and they suggested that the cream was failing the stability test due to a phenomenon called “sweating” and that I should stabilize the water phase with more emulsifier, or a polymeric thickener or a solubilizer…

  • rodb1958

    Member
    April 2, 2019 at 1:39 am

    40C isn’t overly high and i would use 6mths at 40C to establish a 2year at RT shelf life although there’ll be many comments/counterclaims based on the experience of others. Try centrifuging a aliquot of the emulsion, 5-10g or so. Run it for 30-40min at 4000 rpm (you can calc the g-force) if there’s no separation -all good and you likely have condensation. 

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