Moist Heat Sterilization

Moist Heat Sterilization

Steam Sterilization

In addition to instructions for cleaning, manufacturers of reusable medical devices must provide complete written instructions for disinfection or sterilization following cleaning to ensure that the device can be used safely and for the purpose for which it is intended. Manufacturers are obligated under the Food and Drug Administration (FDA) labeling regulations (21 CFR 801) to have the suitability of these processes validated. 

LexaMed is an industry leader in designing and performing sterilization validations for reusable medical devices processed at health care facilities and has extensive experience in validating moist heat (gravity or prevacuum), ethylene oxide (EO), and dry heat sterilization modalities. Every device is different therefore each program begins with generation of a unique protocol by an experienced project manager followed by study execution by trained microbiologists using fully validated and calibrated sterilizers.  

The validation protocol and testing are developed and conducted in compliance with the following standards:

  • AAMI TIR 12 (ST98 draft) A compendium of processes, materials, test methods, and acceptance criteria for cleaning reusable medical devices
  • ISO 17664 Processing of health care products—Information to be provided by the medical device manufacturer for the processing of medical devices
  • ISO 17665 ANSI/AAMI/ISO 17665-1 Sterilization of health care products—Moist heat—Part1
  • FDA guidance document Reprocessing Medical Devices in Health Care Settings: Validation Methods and Labeling
  • ISO 11135 Sterilization of health-care products — Ethylene oxide
Protocol Development

Working closely with the study sponsor the LexaMed project manager will attain an understanding of the device and the Instructions For Use (IFU) sterilization instructions.  Using the information, a protocol will be generated that will ensure all elements of the various standards are properly incorporated including things such as Biological Indicator (BI) choice, justification of worst-case inoculation sites and acceptance criteria for the chosen method of sterilization.  The study sponsor will be asked to review and approve the protocol prior to study initiation.

Study Design

The study is designed to confirm the appropriate Sterility Assurance Level (SAL), dry time (if appropriate) and thermoprofiling of the device.  Typically, a SAL of 106 is validated using the biological indicator overkill method described in the various standards.  Devices are inoculated with BIs at worst case locations then exposed to the IFU stated sterilization cycle however the exposure time is one half of the routine sterilization time.  Following exposure, the BIs are tested for sterility to confirm the half  cycle was effective in achieving sterilization.   Successful results validate the  sterilization parameters, and the manufacturer will be able to provide health care facilities with validated sterilization parameters.

When performing a moist heat (gravity or prevacuum) sterilization validation an additional dry time study is conducted to ensure the packaging and the device are not wet following sterilization as moisture may compromise the sterile properties of the packaged device.  When performing ethylene oxide (EO) sterilization validations EO residual analysis is conducted on sterilized items to establish an appropriate aeration time for the devices following sterilization.   A comprehensive report summarizing testing and results is provided at the conclusion of the study.

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