Home Cosmetic Science Talk Formulating Testing products that you’ve used for years

  • Perry44

    Professional Chemist / Formulator
    March 31, 2025 at 7:39 pm

    Typically, you’ll want to at least do microbial contamination testing on every batch just to ensure that it doesn’t get contaminated. Also, you should probably do a limited stability test every couple months on your batches to make sure that when you’ve changed lots of ingredients the product is still stable. You should also have a retain of every batch you make stored at Room Temperature just so you can verify that it remains stable and safe.

  • PhilGeis

    Member
    April 1, 2025 at 6:04 am

    If you’ve completed the stability series - hopefully though 3 years- not beyond change control.

  • MaidenOrangeBlossom

    Member
    April 1, 2025 at 7:27 pm

    How large does the sample need to be? The products are expensive so I wanted to keep maybe a 10ml sample?

    • Aniela

      Member
      April 2, 2025 at 9:03 am

      Regardless the cost, the “observation-sample” should be the same size as the one you’re selling, and in the same type of packaging.

      • MaidenOrangeBlossom

        Member
        April 2, 2025 at 12:19 pm

        How long do I have to keep the sample. At the moment I do not have a way to organize batch codes, if I wanted to begin that process, can I do so manually? I am not a large seller so I could feasibly just make up numbers and print labels to add to the products.

        • Aniela

          Member
          April 2, 2025 at 1:45 pm

          The time you keep the sample should be equal to the shelf-life of your product.

          No hard rules on labelling, manually is fine.

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