Medical Device Sterilization
Most surgical and medical devices used in healthcare facilities are made of materials that are heat stable and therefore undergo heat, primarily steam, sterilization. Medical devices that have contact with sterile body tissues or fluids are considered critical items. These items should be sterile when used because any microbial contamination could result in disease transmission. Such items include surgical instruments, biopsy forceps, and implanted medical devices.
Sterilization is a process that effectively destroy all microorganisms from the surface of an article or in a fluid to prevent disease transmission associated with the use of that item. Sterility is a state of being free from viable organisms. In practice, no such absolute statement regarding the absence of microorganisms can be proven. Therefore, a Sterility Assurance Level (SAL) is used to define the objective in sterilization processing.
Types of Medical Device Sterilization
Types of sterilization
- Established sterilization method.
- Novel sterilization method.
Established sterilization method: It is further divided into two sub classes.
- Established category A
- Established category B
Established category A: Methods which FDA believes have long history of safe and effective use. Methods covered under Established category A are:
- Dry heat
- Ethylene oxide (EO) with devices in a fixed, rigid chamber
- Moist heat or steam
- Radiation (e.g., gamma, electron beam).
Established category B: Methods that were originally listed in FDA’s draft guidance as “non-traditional” or “novel non-traditional,” but the agency now describes these as “established methods for which there are no FDA-recognized dedicated consensus standards, but for which published information on development, validation, and routine control is available.”
Methods covered under Established category B are:
- Hydrogen peroxide (H2O2)
- Ozone (O3)
- Flexible bag systems (e.g., EO in a flexible bag system, diffusion method, injection method)
Novel sterilization method: A Novel sterilization method is a method that FDA has not reviewed and determined to be adequate to effectively sterilize the device for its intended use. Novel methods use chemicals that was previously not been cleared and got approved by FDA and has not been identified as chemical sterilant would be considered novel.
Methods covered under novel sterilization are:
- Vaporized peracetic acid
- High intensity light or pulse light
- Microwave radiation
- Sound waves
- Ultraviolet light
- high intensity light or pulse light
Evidences to be submitted for 510k
Following documents should be submitted while filling 510(K) in case of Established sterilization method:
- Description of the method that will be used to validate the sterilization cycle, but not the validation data itself
- Clear statement should be given for methods falling under Established category B, means they did not get any type of clearance from 510(K) previously.
- The sterility assurance level (SAL) for the device which the firm intends to meet
- A description of the packaging to maintain the device’s sterility (this is not to include packaging integrity testing data)
- If sterilization involved ETO, the maximum levels of residues of ethylene oxide, ethylene chlorohydrin, and ethylene glycol which remain on the device
- Whether the product is “pyrogen free’ and a description of the method used to make the determination
- The radiation dose of radiation sterilization will be used.
Following documents should be submitted while filling 510(K) in case of Novel sterilization method:
- A comprehensive description of the sterilization process
- The method used to validate the sterilization cycle (e.g., the half-cycle method)
- The validation protocols
- The sterilization validation data. The submission should also identify any applicable published scientific literature. For novel sterilization methods, FDA may also request additional information based on the specific device submitted for review.