Moving from Ethylene Oxide to Gamma Sterilization - What is required?

A

arios

Folks

Please share experience, sources, precautions and reference to standards that should be considered :read: when changing a Medical Device sterilization method from ETO to Gamma Sterilization.

a) Will the shelf life be affected?
b) Is new age testing required?
c) Once a first product is "converted" how to use it as "parent" for future adoptions of same dose for other devices under the same family

Thanks
 
M

MIREGMGR

a) Will the shelf life be affected? b) Is new age testing required?

If polymers are involved, yes. Everything related to polymers and polymer-based adhesives has to be re-evaluated. This is best done by running the product through the design process again, because materials may need to be changed to achieve the required mechanical performance, functionality may change, biocompatibility may change, aging behavior may change. The color and even the smell of polymers may change.
 

Ronen E

Problem Solver
Moderator
Folks

Please share experience, sources, precautions and reference to standards that should be considered :read: when changing a Medical Device sterilization method from ETO to Gamma Sterilization.

a) Will the shelf life be affected?
b) Is new age testing required?
c) Once a first product is "converted" how to use it as "parent" for future adoptions of same dose for other devices under the same family

Thanks

Hi Alberto,

Please note that some materials (especially polymers) are completely incompatible with Gamma irradiation, e.g. some plastics would degrade to the point of disintegration (some POMs), not to mention reduction in mechanical properties, colour shift (PCs) etc. in othres.

ISO 11137 is a must if you're considering Gamma sterilization.

I tend to agree with MIREGMGR on (a) and (b), unless you have a truly solid justification to show otherwise. On (c), it depends on how diverse is the "family". I would say that unless the differences within the family are pretty minor, you would need to validate every member. Anyway, if you follow ISO 11137 closely you'll be able to determine that.

Good luck,
Ronen.
 

Ajit Basrur

Leader
Admin
Folks

Please share experience, sources, precautions and reference to standards that should be considered :read: when changing a Medical Device sterilization method from ETO to Gamma Sterilization.

a) Will the shelf life be affected?
b) Is new age testing required?
c) Once a first product is "converted" how to use it as "parent" for future adoptions of same dose for other devices under the same family

Thanks

Alberto,

Two experts have summed up all :agree1:

You would have to start from the beginning ie. design controls.
 

harry

Trusted Information Resource
A white paper for anyone interested: Effect of Gamma Sterilization on Select TPE Materials


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A

arios

On the process to learn more about this topic I found this web link with great information:

http :// www. nordion. com /documents/Gamma_Compatible_Materials_List.pdf DEAD - 404 - LINK UNLINKED

It is a table with Polymer names and their maximum gamma dose they can withstand.
 
Last edited by a moderator:

Ronen E

Problem Solver
Moderator
On the process to learn more about this topic I found this web link with great information:

http ://www .nordion .com/documents/Gamma_Compatible_Materials_List.pdf - DEAD - 404 - LINK UNLINKED

It is a table with Polymer names and their maximum gamma dose they can withstand.

Hi,

Take it with a grain of salt. It might be OK as a hi-level guide but I'd say it's a bit simplistic. Compatibility analysis should be specific-grade-based, as some of the generic families are too diverse for generalizations.

With regards to sterilization, I'd say anything below 50KGy should be regarded as incompatible (some would say even 70-80KGy, because the specified upper dose limit on most "normal" Gamma irradiation processes is 35-40KGy).

Cheers,
Ronen.
 
Last edited by a moderator:
A

arios

Folks,

I deeply appreciate the previous comments, I have still some few questions to ask:

How would the change from Eto to Gamma affect the sterile barrier?

(assuming that one combination of blister-tyvek or pouch has been previously validated for its use in Eto)

Are there studies made on this part of the change?

Or is it good to assume that anything that was good for Eto will be as good for Gamma as well?
 
M

MIREGMGR

There's no need to use an expensive EtO pouch for a gamma product, since humidity and gas flow aren't relevant. Also, most EtO pouch materials aren't designed for gamma stability. Use gamma specific packaging instead. Talk to packaging vendors to learn what's available.

You don't just take an EtO-validated product system and start running it through gamma.
 
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