Significant Change After Photostability Testing

All Situation Room examples are constructed and not descriptions of actual events.

Published on: March 5, 2024
Walter Routh
Categories: The Situation Room
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What is the stability situation?

We have a 2-year-old photostability chamber that has been performing well. It is well mapped, temperature and humidity controlled, and the bulbs are relatively fresh—just changed out a month ago. To perform confirmatory testing, in three petri dishes we place 20 tablets of our new drug product, each in a single layer. We left the dishes uncovered for the relatively short Option 2 exposure. Since the chamber is temperature controlled, we opted not to run a dark control. According to the sampling plan, after exposure, 10 tablets were removed from each, placed in a sample container and sent to the lab for assay, degs and appearance and color. The other 10 tablets were placed in a separate container and not sent to the lab.

Within three days the lab reported that we had assay results of (1)99.8%, (2)97.9% and (3)94.3% vs. initial results of 99.6% of the label claim (specifications are 95% to 105%). After an initial investigation the remaining sample was sent for testing per a pre-approved retest plan, with those results at (1)99.6%, (2), 98.5% and (3)95.2%, confirming the initial findings. Mass balance checked out, as well, with total degs of sample (3) at close to 4%. We suspect variability within the chamber, but we did not record the exact location of the petri dishes during exposure in order to recreate the exposure conditions.

How should this be resolved?

Here are some possible courses of action:

1. Run with the confirmed results and either add light protection to the product or modify the label to warn against light sensitivity. Clearly the sample results show the product is light sensitive and this can’t be ignored.

2. Re-map light exposure in the chamber using enough sensors to cover the diameter of the petri dishes and hopefully pinpoint the suspected light hotspot. Use those findings (hopefully) to repeat the study.

3. Repeat the study with sample in the primary package. For good measure, given these strange results, also include sample in the proposed market package.

4. Portions of two and three combined.

We Want to Hear Your Thoughts!

  • March 2, 2025

    Your Honor, where do we turn if money is not available to purchase stability chambers and alternative storage options are not readily available? Budget timing and quality roadblocks are putting stability chamber space in danger of overflowing.

  • February 7, 2025

    Upper management has a dangerously low awareness and vigilance of stability. They haven’t had a significant event or audit observation to raise alarms and put us at top of mind. As a result, we get the dregs of personnel and budget—this needs to change.

  • January 4, 2025

    Samples swapped identities when human error caused incorrect storage conditions to be tested, but the only evidence is historical data trends. How can they prevent the error and shore up sample integrity?

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A stabilitarian encounters new situations every day. StabilityHub’s discussion forums give Stabilitarians an opportunity to ask questions and offer solutions to specific scenarios. Join in the conversations with other Stabilitiarians and share your knowledge!