Often the answer to that question dictates the method as one may only be able to use EO (or another gaseous niche method), or radiation may be the only method that works. If the product is designed with sterilization in mind and can be processed with either a gaseous or radiation methods, then the second question comes into play.
On November 7 PMP News published the article, "How to Make the Choice between Ethylene Oxide or E-Beam Sterilization," by Freelance Journalist Camilla Andersson. It was also included in the Medical Packaging Community. The article discussed the choice between Electron beam (E-beam) sterilization and ethylene oxide (EO). PMP News received the following letter in response to that article:
EO is the most popular and growing slightly because it is the most material friendly. As devices get more complex (e.g. combination products, custom kits, others), they may be made of multiple materials, some of which may not be compatible with radiation. EO can also be used in some instances where products contain computer chips as they will not affect their performance, whereas radiation processing will generally not work for these items. One of its main historical drawbacks is that it typically had the longest turnaround time as compared to radiation processing. However, with the advent of things like combining All-In-One processing with parametric release, the turnaround time, where this can be used, rivals that of the radiation techniques.
Medical device manufacturers choosing to sterilize their products and packaging face numerous options. One of these choices is between Electron beam (E-beam) sterilization and ethylene oxide (EO). Sometimes, the choice is easily made based on factors such as product limitations and sensitivity to radiation or heat, but at other times, either method seems suitable. In these cases, time-to-market and cost considerations might be the determining factors.
Someone recently told me that a minimum of 30 cycles with biological indicators (BIs) is required to validate parametric release. Is that true? I have not been able to find a requirement in any sterilization standard that requires this. Also, is there any significant difference in using a biological indicator release or parametric release?
How to Make the Choice between Ethylene Oxide or E-Beam Sterilization.
Q: What is the sterility assurance level (SAL) when performing an ethylene oxide (EO) Overkill Method qualification using the half cycle approach where 10 biological indicators (BIs) were used, tested, and there was 0 positives obtained (complete kill). Many people would say that the minimum SAL in this example would be 10-6, but it is actually greater than that.
The breakdown of industry sterilization is generally agreed to be roughly 52% ethylene oxide (EO) gas, 36% Gamma radiation, and 7% E-beam radiation. The remaining 5% are various modalities like steam, hydrogen peroxide, gas plasma, nitrogen dioxide (NO2), peracetic acid (PAA) and some others. In total, there are only about 25 sterilization methods known to mankind.
Q: What is the best way to determine EO concentration in the sterilization chamber?
Q: I'm designing a sterilization validation and, in general, a sterilization assurance system. All the products that will be sterilized were reviewed by a qualified team and only few products were shortlisted, being the most difficult to be sterilized products. Is it mandatory to select only one "Worst-case product" before entering the sterilization validation (ISO 11135:2014 annex B) or can I start the validation with more than one candidates "worst-case products"? Working with an Overkill approach, I can for example demonstrate the appropriateness of the internal PCD, comparing it with all candidate products in sublethal cycles! Is it mandatory to identify the most difficult to sterilize location within the product? How can I use this information in following validation steps? According to ISO 11135:2014 (8.6) "The PCD shall present a challenge to the sterilization process that is equivalent or greater than the challenge presented by the natural bioburden at the most difficult to sterilize location within the product". In my case I have more than one products / locations but it is possible to analyze whole product (for all candidate products) so I suppose there is no need to identify the most difficult to sterilize location.