Hello everyone,
So our company is planning to perform a full sterilization validation for 1 of our key product which is the coronary stent. However, we are very new to this process and still have a lot to learn. I have read ISO 11135 and watched a lot of youtube tutorials on how to perform a sterilization validation, but there are many things that i'm still confused, so I hope that I can received some guidance from you all. So here are my questions:
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To my understanding, 1 of the main purposes of the whole sterilization validation process is to prove that the resistance of natural bioburden on the product is less than the resistance of the selected iPCD, and the resistance of the iPCD is less than that of the ePCD ( product < iPCD < ePCD ).
The purpose of using an iPCD is to prove that the sterilization cycle can achieve SAL = 10^-6, and the purpose of using an ePCD is to provide a reliable, easy-to-retrieve monitoring tool for routine cycles. For our product, the use of an ePCD is neccesary because 2 reasons. First, because our product is quite expensive and because in order to create 1 iPCD we basically have to sacrifice 1 product, it's is economically impractical to use iPCDs for monitoring routine cycles. Second, it's very difficult to inoculate our product and it's equally hard to retrieve the BI, thus we want to develop an ePCD so that we can easily retrieve the BI to monitor routine cycles.
(1. How to develop a proper ePCD?) .To create an iPCD, we decided to inoculate our product (stent) by inserting a mini BI spore strip into the most difficult place to sterilize in the product which is between the stent and the balloon. However, i don't know how to develop an appropriate ePCD. Is there any standard guidance or instruction on how to develop a proper ePCD? I just plan on inserting a BI tube into the barrel of a capped syringe. This system, to my evaluation, poses the hardest challenge for sterilization as a capped syringe bascially has no clear entrance/path for EO gas to go into its barrel, thus the only way is the EO gas has to penetrate through the syringe body to reach the BI tube in its barrel. Do you think this is a good choice of ePCD ? I do realize that there are some available commercial ePCDs, however their prices are relatively high, so we prefer developing a cheaper self-made ePCD if possible.
(2. How to prove the resistance of iPCD < the resistance of ePCD?) Also, i don't know how to prove the resistance of iPCD is less than the resistance of ePCD ( iPCD < ePCD ). I know how to prove (product < iPCD). To do this, I have to run a sub-lethal (fractional) cycle, and the result should be all product is sterile and some growth on iPCD. But does this same method apply to prove (iPCD < ePCD)? I was guessing the way to do it is to run another fractional cycle to achieve a result in which the number of sterile iPCDs is more than the number of sterile ePCDs. So for example, i use 10 iPCDs and 10 ePCDs, and I need to run multiple fractional cycles until I get a result of ,let's say, 7 iPCDs are sterile and 2 ePCDs are sterile. But again, i'm not really sure about this.
(3. What result do I need to get for half-cycle?) Assuming I am able to prove (iPCD < ePCD) using fractional cycles, so do all ePCDs need to be sterile after half-cycle ? Because the requirement from ISO 11135 is achieving SAL = 10^-6, and we can prove this by having all iPCD sterilized after half-cycle. But because the resistance of iPCD < ePCD,there is a chance that not all ePCDs are sterile after half-cycle. So do we need to find a set of half-cycle parameters that can sterilize all ePCDs ?
(4. Loading?) Can we use the same load again and again for all the cycles? I know, optimally, we should use a new load for each cycle. But again our product is quite expensive, and even if we use similar products (dummy load) the cost is still high.
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I know it's a long posts and there are a lot of basic questions. So thank you in advance for helping me!
So our company is planning to perform a full sterilization validation for 1 of our key product which is the coronary stent. However, we are very new to this process and still have a lot to learn. I have read ISO 11135 and watched a lot of youtube tutorials on how to perform a sterilization validation, but there are many things that i'm still confused, so I hope that I can received some guidance from you all. So here are my questions:
-----------------------------
To my understanding, 1 of the main purposes of the whole sterilization validation process is to prove that the resistance of natural bioburden on the product is less than the resistance of the selected iPCD, and the resistance of the iPCD is less than that of the ePCD ( product < iPCD < ePCD ).
The purpose of using an iPCD is to prove that the sterilization cycle can achieve SAL = 10^-6, and the purpose of using an ePCD is to provide a reliable, easy-to-retrieve monitoring tool for routine cycles. For our product, the use of an ePCD is neccesary because 2 reasons. First, because our product is quite expensive and because in order to create 1 iPCD we basically have to sacrifice 1 product, it's is economically impractical to use iPCDs for monitoring routine cycles. Second, it's very difficult to inoculate our product and it's equally hard to retrieve the BI, thus we want to develop an ePCD so that we can easily retrieve the BI to monitor routine cycles.
(1. How to develop a proper ePCD?) .To create an iPCD, we decided to inoculate our product (stent) by inserting a mini BI spore strip into the most difficult place to sterilize in the product which is between the stent and the balloon. However, i don't know how to develop an appropriate ePCD. Is there any standard guidance or instruction on how to develop a proper ePCD? I just plan on inserting a BI tube into the barrel of a capped syringe. This system, to my evaluation, poses the hardest challenge for sterilization as a capped syringe bascially has no clear entrance/path for EO gas to go into its barrel, thus the only way is the EO gas has to penetrate through the syringe body to reach the BI tube in its barrel. Do you think this is a good choice of ePCD ? I do realize that there are some available commercial ePCDs, however their prices are relatively high, so we prefer developing a cheaper self-made ePCD if possible.
(2. How to prove the resistance of iPCD < the resistance of ePCD?) Also, i don't know how to prove the resistance of iPCD is less than the resistance of ePCD ( iPCD < ePCD ). I know how to prove (product < iPCD). To do this, I have to run a sub-lethal (fractional) cycle, and the result should be all product is sterile and some growth on iPCD. But does this same method apply to prove (iPCD < ePCD)? I was guessing the way to do it is to run another fractional cycle to achieve a result in which the number of sterile iPCDs is more than the number of sterile ePCDs. So for example, i use 10 iPCDs and 10 ePCDs, and I need to run multiple fractional cycles until I get a result of ,let's say, 7 iPCDs are sterile and 2 ePCDs are sterile. But again, i'm not really sure about this.
(3. What result do I need to get for half-cycle?) Assuming I am able to prove (iPCD < ePCD) using fractional cycles, so do all ePCDs need to be sterile after half-cycle ? Because the requirement from ISO 11135 is achieving SAL = 10^-6, and we can prove this by having all iPCD sterilized after half-cycle. But because the resistance of iPCD < ePCD,there is a chance that not all ePCDs are sterile after half-cycle. So do we need to find a set of half-cycle parameters that can sterilize all ePCDs ?
(4. Loading?) Can we use the same load again and again for all the cycles? I know, optimally, we should use a new load for each cycle. But again our product is quite expensive, and even if we use similar products (dummy load) the cost is still high.
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I know it's a long posts and there are a lot of basic questions. So thank you in advance for helping me!
