Hello,

I have some questions about polyprolene sterilization with heat autoclave. During the sterilization, I have seen that the polypropylene is expanding and deforming. The issue is that it doesn't come back to the original form at the end.

Any idea on how to fix this?

Thanks!

Hello,

I have some questions about polyprolene sterilization with heat autoclave. During the sterilization, I have seen that the polypropylene is expanding and deforming. The issue is that it doesn't come back to the original form at the end.

Any idea on how to fix this?

Thanks!

Welcome Firebird,

If a sterilization process results in damage to your material, chances are you had chosen a wrong process. How about using low temperature sterilization processes such as ETO (Ethylene Oxide)?

Hello,

I have some questions about polyprolene sterilization with heat autoclave. During the sterilization, I have seen that the polypropylene is expanding and deforming. The issue is that it doesn't come back to the original form at the end.

Any idea on how to fix this?

Thanks!Welcome to The Cove, firebird! :bigwave:

I looked up this site and found it claims polypropylene does poorly in sterilization autoclaves. Sterilization stability of materials (http://www.eldonjames.com/frames/sterilize.html)

I did a little further searching and found Clear, Radiation-Tolerant, Autoclavable Polypropylene (http://www.devicelink.com/mpb/archive/97/01/003.html)

Have you always had this problem, or is it occurring with a new batch of materials?

Hello Jennifer,

Sounds like you are using google better than me ;)

Thanks a lot for these very interesting documents. Reading these, I understand that the formulation of the polypropylene is very important for its autoclavability.

Fact is that I am currently testing the process to sterilize polypopylene forms so I didn't had any exposure to it before.

Harry,

Ethylene Oxide isn't really an option as my autoclave is working with heat. I also know that it is possible to sterilize polypropylene with heat but I just didn't manage to do it right now.

Any idea is more than welcome.

I also know that it is possible to sterilize polypropylene with heat but I just didn't manage to do it right now.

Any idea is more than welcome.
Hi Firebird,

If you have to use moist heat then one option open to you is to use the F0 principle to give you flexibility to deliver the required sterility assurance level using a different temperature/time combination. Using a lower temperature (which must be above 100 degree Centigrade) for longer will allow you to deliver a lethal process, with less thermal stress on your polypropylene.

Alternatively if the deformation is happening because of time at the sterilizing temperature, you could ramp up the temperature and cut the time. Using an assumed Z value of 10 degrees you can deliver the same lethality as 15 minutes at 121 degrees using a 150 minute cycle at 111 degrees, or 1.5 minutes at 131 degrees. Obviously this depends on the bioburden numbers and resistance, but there is a level of flexibility using this method that may allow you to continue with moist heat for polypropylene.

I may be able to dig out some references if this approach interests you.

regards,

Jimmy

Hi Jimmy the Brit,

Thanks a lot for these details. My thought is that I have to go up to 121°C in order to effectively sterilize the PP but I think it could be interesting to try at less during a longer period, just to see.

If you have any references, I am very interested to see these.

Thanks again!

Hello,

I have some questions about polyprolene sterilization with heat autoclave. During the sterilization, I have seen that the polypropylene is expanding and deforming. The issue is that it doesn't come back to the original form at the end.

Any idea on how to fix this?

Thanks!

Hi firebird,

Have you investigated the root cause for the deformation ? What is the duration of your autoclaving cycle and what is the highest temperature that the PP is exposed during this cycle ?

My experience with PP sterilization is that the material gets deformed at temperatures above 127 deg C during the autoclaving cycle.

Btw, what is the article that is autoclaved ?

Thanks a lot for these details. My thought is that I have to go up to 121°C in order to effectively sterilize the PP but I think it could be interesting to try at less during a longer period, just to see.

If you have any references, I am very interested to see these.
Hi Firebird,

I would recommend these three as the best place to start:

Halls N.A (1994) "Achieving Sterility in Medical and Pharmaceutical Products" , New York: Marcel Dekker, Inc.
Pflug, I.J et al (2000) "Disinfection, sterilization and preservation" 5th Rev.Ed. Lippincott William and Wilkins
PDA technical report number:1 (2007) Validation of Moist Heat Sterilization Processes Vol 61, No S1PDA Journal of pharmaceutical science and technology (I realise that this is a pharma document, but it contains a good F0 concept section)
I hope this helps - if not let me know - F0 isn't everone's cup of tea, but I do believe that it is the answer to your problem.

Jimmy

Hi firebird,

Have you investigated the root cause for the deformation ? What is the duration of your autoclaving cycle and what is the highest temperature that the PP is exposed during this cycle ?

My experience with PP sterilization is that the material gets deformed at temperatures above 127 deg C during the autoclaving cycle.

Btw, what is the article that is autoclaved ?

Hi Ajit,

The autoclaving cycle is supposed to last 20 minutes at 121°C. We are starting to see some deformations at 115°C.

The article is a solution into a PP container (few ml).

Autoclaving at a lower temperature could be an option but the cycle would be longer and that's a problem as the PP is supposed to work until 121°C...

Jimmy,

Thanks for the ref ;)

Cheers

We are now wondering if the problem doesn't come from the counter pressure on the PP container...