Home Cosmetic Science Talk Formulating General Expiration Dating

  • Expiration Dating

    Posted by PwrsNY on April 10, 2024 at 4:30 pm

    How do you determine after doing a formula stability test how long a product will be good for ? If stable for 3 weeks in an Incubator at 42°C what is the Exp. date assignation ? and if a bulk product is made, but not sold through can something be done to extend the expiration date so that it doesn’t have to be discarded if it still appears to be in good shape and passed a micro test ?

    PwrsNY replied 2 weeks, 6 days ago 2 Members · 8 Replies
  • 8 Replies
  • PhilGeis

    Member
    April 11, 2024 at 9:43 am

    3 weeks isn’t a useful period. The concept is borrowed from OTC drug reg and there the rule of thumb projects 1 year stability projected from appropriate testing (including challenge) of product after 3 months at 40-42C. https://www.chpa.org/public-policy-regulatory/voluntary-codes-guidelines/guideline-stability-testing-nonprescription-otc

    I know some in the cosmetics industry have used 1 month 40-42 for 1 year and 3 months for 2 based on validation with their own data.

    In any case, you mist still run stability qualification of real time aged products to confirm and have a plan to address (recall?) if failure observed in real time testing.

    • This reply was modified 2 weeks, 6 days ago by  PhilGeis.
  • PwrsNY

    Member
    April 11, 2024 at 9:51 am

    That is very helpful. THank you. Any insight on extending bulk shelf life after expiry ? If a product is still stable ?

  • PhilGeis

    Member
    April 11, 2024 at 10:31 am

    Storing bulk for an extended period is a stability complication as it’s different -volume/humidity/ temperature/container composition - vs finished packaged product. Ideally you would perform finished product stability using the old, aged-in-bulk product subsequently packed out for sale - not fresh as chemical changes started the moment product was made, not just when it went into final consumer package.

    • PwrsNY

      Member
      April 11, 2024 at 10:37 am

      So should expiration dates be assigned when a product is filled into packaging or when a product is dropped from Batch? My company had lipstick for example that we assign a 2 year expiration date to from the date the Batch was made. But sometimes filling is not drawn off that Batch for a year and a half which renders the expiration date closely approaching, but the bulk lipstick still appears in good form… We draw off the Bulk as needed to fill. I am trying to see how to extend those expiration dates so that we do not have to throw good material away if sales may be slow for a particular color that year…..

      • PhilGeis

        Member
        April 11, 2024 at 11:32 am

        If you’re not worried about preservative/preservation, you’ve got more flexibility. You maybe looking at a consumer perception matter, the risk to your brand not consumer safety.

        What stability parameters are you running?

        • PwrsNY

          Member
          April 11, 2024 at 1:25 pm

          Correct, I had one client accept an extended 2 year expiration date off the original manufacturing date and another client say it was unacceptable… We completed a new C of A which reviewed texture, odor ( rancidity ), appearance, melting point, after subjecting the Batch to heat in a kettle and remix just to make sure any contamination was eliminated and that the bulk functions as normal….On lipstick I am not worried about the preservative system as this particular formulary is almost impossible to grow microbes… I was just wondering if this is acceptable to regulatory agencies or if it is strictly up to the manufacturer who feels the product is still good and stable and then gaging acceptance from clients on whether it is acceptable or not based on their perspectives as you mentioned…..

          • PhilGeis

            Member
            April 11, 2024 at 2:40 pm

            Heating to eliminate contamination? Micro stability derives from preservation - that is intended to protect consumer in use. Heating serves no purpose and could compromise the preservative.

            • PwrsNY

              Member
              April 11, 2024 at 2:51 pm

              It is a lipstick that does not need a preservative… But I understand what you are saying… it would not serve a purpose from a microbial standpoint…

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