Sterilization in the medical device industry is all about ensuring that every tool, instrument, or piece of equipment used in healthcare is free from any living microorganisms. The efficacy of sterilization plays a pivotal role in preventing infections and maintaining public health. As such, the medical device industry relies heavily on precise sterilization techniques to maintain the highest standards of cleanliness and safety.
Understanding how sterilization works is crucial for anyone involved in the healthcare field, as it directly impacts patient outcomes and overall public health. Learn more about the essentials of sterilization in the medical device industry, its significance, and how these processes preserve public health with this guide to how sterilization efficacy is tested in medical devices.
Importance of Sterilization Efficacy in Protecting Public Health
Sterilization efficacy is a promise to protect public health. The significance of effective sterilization cannot be overstated, as it forms the backbone of infection control in healthcare settings. When sterilization processes are not effective, there is a risk of infections spreading, which can lead to severe health consequences.
Ensuring that medical devices are properly sterilized is essential for patient safety and the prevention of healthcare-associated infections. This commitment to sterilization efficacy reflects the broader goal of safeguarding public health and ensuring the highest standards of care.
Sterilization Testing Basics
Testing the efficacy of sterilization is a meticulous process that involves a series of steps to ensure that medical devices are free from harmful microorganisms. The overarching goal of the entire sterilization validation process is to document that the sterilization method is both reliable and effective in eliminating potential threats to patient safety.
In addition to conducting the intended sterilization method for a device and verifying that it achieves the necessary level of sterility, this process can include additional tests and processes. Further validation processes, such as microbial challenge tests, shelf-life testing, dry time tests, and more, help identify any problems that might occur during the reprocessing in a real-world setting.
Different Sterilization Methods
There are several sterilization methods employed in the medical device industry, each with its own advantages and considerations. Choosing the right method is crucial for ensuring that the device is compatible with the sterilization process and that the desired level of sterility is achieved.
Each method has specific applications and is selected based on the type of device and the materials used. Understanding these methods and their applications is key to ensuring effective sterilization. The United States Food and Drug Administration (FDA) categorizes two types of sterilization processes in US healthcare, as either “established” or “novel” sterilization. Let’s look at some of the most popular established sterilization processes used with reusable medical devices.
Steam
Steam sterilization is the most common methods used in the reprocessing of medical devices in the healthcare industry. There are two types of steam sterilization: gravity and dynamic air removal, which is also known as pre-vacuum sterilization. Both work by using high-pressure steam to kill microorganisms. This method involves parameters such as sterilization temperature, exposure time, and pressure. To validate steam sterilization, testers must confirm that the steam process reduces microorganisms to an acceptable number without damaging the device through heat, pressure, or residual moisture.
Dry Heat
Dry heat sterilization is another method used to achieve sterility in medical devices. Unlike steam sterilization, this method uses high temperatures without moisture to kill microorganisms. The process involves exposing the device to dry heat through either static air or forced air.
Dry heat is beneficial in some healthcare markets because of its low operating costs and its ability to penetrate materials without causing corrosion or other damage.
Ethylene Oxide Gas
Ethylene oxide gas sterilization is a method that uses a chemical gas to achieve sterility in medical devices. This is a low-temperature sterilization method that is particularly effective for heat-sensitive materials that cannot withstand high temperatures. The process involves exposing the device to ethylene oxide gas in a sealed chamber for a specific period of time. The gas kills microorganisms on the device. The process ends by aerating the chamber to remove the gas and retrieve the device.
This method is commonly used for sterilizing delicate materials or devices that feature multiple layers or intricate designs with hard-to-reach places.
Vaporized Hydrogen Peroxide
Vaporized hydrogen peroxide sterilization is a relatively new “established” method that uses vaporized hydrogen peroxide gas to achieve sterility. Because the hydrogen peroxide molecules are highly reactive, they do a thorough job of penetrating the device materials and killing microorganisms. Moreover, the hydrogen peroxide vapor breaks down into water and oxygen at the end of the process, leaving no residue on the device.
Testing for Worst-Case Conditions
A critical aspect of how sterilization efficacy is tested in medical devices involves evaluating the sterilization process under the most challenging conditions to ensure that it remains effective and reliable. This type of evaluation is referred to as worst-case conditions testing. These conditions include running the test in FDA-cleared sterilization cycles, using half the intended sterilization exposure time, sterilizing higher levels of highly resistant microorganisms (biological indicators), and placing the biological indicators in a less effective location in the device for sterilization.
By intentionally failing to follow best practices, these tests provide additional assurance that the sterilization process can handle unexpected challenges and still maintain the desired level of sterility. This approach ensures that the sterilization process is robust and capable of achieving the desired level of safety and quality no matter what complications arise in real-world settings.
100% Overkill Method of Sterilization Efficacy Testing
This method is often referred to as the “half-cycle method” or the “overkill sterilization method” and is discussed in many sterilization standards. A sterilization efficacy validation is accomplished by demonstrating that a minimum of 1.0 x 106 highly resistant bacterial spores will be killed in a half-cycle (6-log reduction) of sterilization exposure. Therefore, a full sterilization cycle would result in a 12-log reduction of spores and produce a 10-6 sterility assurance level (SAL), which reflects a one-in-a-million chance of a non-sterile item getting through the sterilization process. A 10-6 SAL is considered the gold standard by worldwide regulatory bodies who review the efficacy data of reusable medical device validation testing.
Sterilization Validation With Highpower
Highpower Labs offers a comprehensive range of sterilization efficacy validation methods for medical device manufacturers. Make our medical device sterilization validation service part of your manufacturing process when you work with Highpower Labs today.