There are many different aspects of sterilization that have to be considered. These include cycle design, process challenge device design, and validation strategy. The ETO Sterilization Guideline has specific recommendations regarding each of these areas. This article will discuss these.
What is the Cycle Design of ETO Sterilization?
For many medical devices, achieving sterility is a top development priority. However, designing and developing a sterilizable package can be challenging. Many project teams ignore the problem until late in the development process. By following a systematic process design approach, designers can achieve safe and effective sterilization without compromising quality.
The ETO sterilization process has a more complex set of variables than most other sterilization technologies. Because of this, designing and developing an efficient, reliable, and safe process requires extensive consideration.
One of the most important steps in the process design process is determining the best ramp rate for your product. This is determined by analyzing your load configuration and product sensitivity.
The size of the cooling exchanger also determines the temperature inside the sterilizer. Increasing the surface area of the exchanger increases the amount of heat transferred.
An efficient cycle requires a control system that is able to inject gases at a steady rate. The system also must be able to perform evacuations at a consistent rate.
Having a robust sterilization process can reduce costs and processing times. It should also be tested at each iteration of your product. This would reduce the materials used and eliminate environmental burden.
Another option is to implement a systematic process design approach for EtO sterilization. This involves a series of experiments to find the most suitable process design.
What is Validation Strategy of ETO Sterilization?
The process of obtaining evidence of the conformity of equipment and process to pre-defined criteria is known as operational qualification (OQ). This can be done by testing simulated loads or biological indicators.
A validated cycle is a process in which a sterilization cycle is performed. A validation should be conducted before performing a full commissioning on a new sterilizer or sterilization unit. It should include a thorough review of all parameters used for routine ethylene oxide sterilization.
There are several different types of tests that can be performed during a validation. However, the most important is the empty chamber profile. This test involves placing probes in a chamber and running a sterilizing cycle. If the profile is empty, the cycle has not contaminated the chamber.
Another type of validated cycle is the microbiologically validated cycle. This is the same cycle as the above but it is microbially tested. Biological indicators are strips with millions of bacteria. Generally, they are species that are resistant to EO gas.
For the best results, a validation should be carried out under the guidance of a qualified team. Those individuals should have experience with the sterilization process and be able to operate measuring devices.
A validation strategy for ETO sterilization guideline should include a variety of testing methods. It should also include a system for routine control of EO. This includes a controller and a recorder.
The aforementioned validation strategy should be implemented in conjunction with the use of a PCD or External PCD. A PCD is a system that simulates contamination of a load.
Process Challenge Device Design of EO Sterilization
The process challenge device is a device that has been used for steam sterilization for years. It can be a pouch, a plastic bag, or a syringe. However, it must be able to resist gas flow.
The design of the challenge device can affect its effectiveness. An external PCD can be more resistant than an internal one. For example, an external PCD may contain a biological indicator (BI) that is resistant to EO.
Biological indicators are used to determine the sterility assurance level (SAL) of a product. They are often species resistant to EO.
In addition to demonstrating resistance to EO, biological indicators can also be used to verify the lethality of a sterilization cycle. A process challenge device is placed around the product, allowing it to be exposed to a number of organisms with known resistance to EO.
Before selecting an external PCD, it is recommended to run a comparative resistance test to ensure that the device is suitable for use. This can be done by running small chambers to determine the times it takes to reach specific pressure set points.
The cycle should be optimized for EO concentration, temperature, and humidity. Using this information, the manufacturer can determine if the product needs to be adjusted for better performance.
Once the ETO concentration is determined, it should be adjusted to eliminate all bacteria. Biological indicators are used to verify that the process is delivering the required SAL.
Depending on the BI, the cycle may be modified to optimize the EO dwell time.
Biological Indicator (BI) Release of Sterilization Processes
Biological indicators are used to monitor sterilization processes. Unlike chemical indicators, BIs provide real-time quantitative information on the performance of a sterilization process. In addition, BIs can be used to provide assurance that a sterilization process has been successful.
Several standards have been established for BI testing, including USP 55 and ISO 11138-1:2017. Biological indicators can be purchased from companies that specialize in infection prevention. They are placed into the sterilizer load in a specially formulated growth medium. The BIs will be cultured under appropriate conditions and then removed from the sterilizer load.
Biological indicators are commonly used for routine steam sterilizer monitoring. However, they can also be used to monitor the ethylene oxide and hydrogen peroxide sterilization processes. BIs are an important tool to use for a wide range of sterilization processes.
A BI test takes about 24-48 hours to complete. For this reason, it is usually performed during a normal production cycle. Alternatively, a product test of sterility may be conducted to verify that the sterilization process meets ISO 11135:2014 requirements.
Parametric Release
Parametric release is a type of control used to release products from the sterilization process. It is not only a cost-effective method of releasing sterile products, but it also helps improve processing times.
There are a number of factors that go into the development of a good parametric release protocol. This includes knowing what the microbiological condition of the starting material is. The correct selection of a suitable sterilization process is also a key factor.
Parametric release is not a new concept. It has been around for years, but the industry has only recently come to a consensus about its proper use.
To qualify for a good parametric release, manufacturers must have a robust sterility assurance system. For example, the minimum specified product temperature must be monitored and validated.
A good parametric release protocol should also be equipped with other ancillary systems, such as gas analysis equipment. Moreover, firms must have the financial wherewithal to invest in this technology. In some instances, the cost of installing this equipment may be recovered in the form of higher fees charged for every load released parametrically.
A good parametric release protocol should be based on a comprehensive specification of the key parameters needed for the release. This can be a result of a user requirement specification, or a product user may develop it themselves.
A good parametric release protocol should have a clear communication path to the customer. It should be able to provide accurate details about the process, including the minimum temperature and the specific load configuration. Using the right information in the right order can help ensure that the product is released correctly.
While a good parametric release protocol is not as simple as the FDA or AAMI would have you believe, there are a number of steps that can be taken to make sure that your company is properly prepared for this new technology.
The Bottom Line
When there were few alternatives for sterilising heat- and moisture-sensitive medical instruments, ETO was developed; moreover, its desirable qualities explain for its ongoing widespread usage. In healthcare facilities, ETO is used to sterilise critical goods that are humidity or temperature reactive and cannot be sanitised by steam sterilisation.
