Using MKT to Justify Normal Temperature Excursions during Qualification: Should you?

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Paul Daniel, Vaisala
Senior GxP Regulatory Compliance Expert
Life Science

(Short answer: No. Long answer and some options: Read on!)

Hi Paul,

In regards to the recent MKT webinar, I have a question. Have you ever used MKT as a scientific justification for normal and acceptable excursions of a cold room (normal defrost) during a qualification?  


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Dear A, 

Thanks for attending the webinar on mean kinetic temperature and thanks for the question! 

The simple answer is no;  I haven't tried that tactic personally. My review of the guidance on MKT directly recommends against use of MKT in a refrigerated environment.  I wouldn't do it personally, unless you know the degradation pathways of the product in question, at the temperatures of 8-12°C are well characterized by the assumptions of the Arrhenius equation.

This doesn't make your problem go away, though… 

The traditional tools for dealing with this are still available to us.  Typically, that would be a detailed mapping during a few defrost cycles to accurately characterize their duration and temperature.  Then evaluating how that impacts the product.  Often this might involve measuring actual product temperatures during the defrost cycle, rather than just air temperatures. 

Or it might mean deciding that there are areas in the cold room that simply aren't suitable to store product.   Cold rooms have always had defrost cycles, and we've always dealt with it with traditional tools.  There may be a better way to do it, but I don't think it is MKT. 

Let me know what you choose to do.  I'd be interested to hear your solution. If you have not already read it, here is our application note on mean kinetic temperature.

Best Regards,

Paul Daniel
Sr. Regulatory Compliance Expert / Validation Program Manager


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Paul Daniel, Vaisala

Senior GxP Regulatory Compliance Expert

Paul Daniel has worked in the GMP-regulated industries for over 25 years helping manufacturers apply good manufacturing practices in a wide range of qualification projects.  His specialties include mapping, monitoring, and computerized systems.  At Vaisala, Paul oversees and guides the validation program for the Vaisala viewLinc environmental monitoring system.  He serves as a customer advocate to ensure the viewLinc environmental monitoring system matches the demanding requirements of life science and regulated applications.  Paul is a graduate of University of California, Berkeley, with a bachelor’s degree in biology.

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