Validation of Reusable Medical Devices –What the FDA Recommends

The growing use of reusable medical devices has led to increased pressure on manufacturers to prove that their reprocessing instructions for use (IFU) are correct. The FDA in their recommendations define “reprocessing as validated processes used to render a medical device, which has been previously used or contaminated, fit for subsequent single use”. Reprocessing of reusable devices involves point-of-use-processing (prompt, initial cleaning steps, measures to prevent drying of soil and contaminants in and on the device), thorough cleaning – done in a dedicated cleaning area and disinfection or sterilization.

The Reprocessing Cycle

Reprocessing involves cleaning, disinfection and sterilization, which are three different processes.

  • Cleaning: Physical removal of soil and contaminants. Effective cleaning should minimize soil transfer from one patient to another or between uses in a single patient; prevent accumulation of residual soil throughout the product’s use life, and allow successful, subsequent disinfection/sterilization steps.
  • Disinfection and sterilization are meant to kill microorganisms.

Cleaning steps should be validated separately and independently from disinfection or sterilization steps.

FDA’s Six Criteria for Reprocessing Instructions

  • Labelling should reflect the intended use of the device
  • Reprocessing instructions for reusable devices should advise users how to thoroughly clean devices
  • For example, devices requiring disassembly for cleaning should have reprocessing instructions with diagrams to adequately explain disassembly. Flushable devices such as endoscopes should have instructions on proper flushing during cleaning procedures.
  • Reprocessing instructions should indicate appropriate microbicidal process for the device
  • The microbicidal process recommended should be sterilization or disinfection (high, intermediate, or low level), depending on the intended use of the device. The FDA explains how devices classified as critical, semi-critical, and non-critical devices must have the respective cleaning methods mentioned.
  • Reprocessing instructions should be technically feasible and include only devices and accessories that are legally marketed.
  • Reprocessing instructions should be comprehensive.
  • To ensure comprehensiveness, they should include details and instructions on special accessories, point-of-use processing, disassembly and reassembly instructions, method of cleaning, appropriate cleaning agents that are compatible with the device, rinsing steps to remove chemical residues, recommended lubricating agents, instructions for visual inspection, at least one specific validated method for disinfection or sterilization, as well as information on a number of other elements.
  • Reprocessing instructions should be understandable

Validation of Cleaning Process

According to FDA guidance, validation activities for the cleaning process should demonstrate two main things. One, that the cleaning methods specified are adequate for the device to undergo further processing and to eventually be reused safely, and, second, that the reprocessing instructions are effective in conveying the proper reprocessing methods to the user.

One method of validating the cleaning process is using the Worst Case Testing method using soils that are relevant to the clinical use conditions of the device.

  • The worst case means that the worst case implementation of the cleaning process should be used, i.e. the least rigorous cleaning process.
  • Medical devices representing the worst case, i.e. the device should be the most challenging to reprocess and should be the most contaminated, should be used in the validation process.
  • The FDA also recommends that at least two quantitative test methods that are related to the clinically relevant soil should be used.
  • The cleaning process validation protocols should specify predetermined cleaning endpoints.
  • The protocols should also establish that the most inaccessible locations on the device can be adequately cleaned during routine processing.
  • The validation protocols should select artificial soil test whose composition represents materials the device is likely to be exposed to during actual clinical use and especially for the worst case cleaning challenge.
  • Soil inoculations should mimic worst-case clinical use conditions.
  • Validation studies should include simulated use conditions, especially for devices with features at risk for the accumulation of soil with repeated use.
  • Validation protocols should support cleaning instructions and should be detailed and specific with respect to parameters such as time, temperature and concentrations.
  • For choosing the two FDA recommended quantitative test methods, factors that should be considered include:
  • The contaminants the device is expected to come in contact with during actual use
  • Test specificity for direct measurement of those constituents
  • Sensitivity of test methods in relation to proposed cleaning endpoints
  • The test methods used to measure residual soil should be validated. The documentation of the method should include analytical sensitivity and specificity information, predetermined cleaning endpoints, and should describe appropriate controls.
  • Devices should be subjected to a validated method of extraction for recovery of residual soil. The extraction method should be completely described for each device and its recovery efficiency should be determined as part of its validation.

Validation of Final Microbicidal Process

The FDA recommends that the disinfection process and instructions should be validated and the recommendations in device-specific FDA guidance documents or relevant FDA-recognized standards should be followed.

  • For reusable devices intended to be used sterile, labelling should include a sterilization process that you have validated to attain a sterility assurance level (SAL) of 10-6 (or 10-3 , as appropriate).
  • Validation data should be generated in FDA-cleared sterilizers and with FDA-cleared sterilization accessories (e.g. biological indicators, physical/chemical sterilization process indicators, sterilization wraps). Alternately, validation data can be generated in sterilizers with equivalent or better control of key sterilization parameters than FDA-cleared sterilizers.

The purpose of validation is to demonstrate that soil and contaminants have been effectively removed and that the device is free from viable microorganisms.

Validation of cleaning, reprocessing and sterilization of reusable medical devices is critical to ensure customer safety, as well as compliance with FDA and other regulatory authorities’ requirements. Knowing the latest regulations is critical for a manufacturer to reduce the likelihood of rejection of submission and additional testing requirements. Firms are subject to quality system regulation even if some cleaning devices of reprocessing reusable medical devices may be exempt from 510(k) premarket notification requirements.

Reusable medical device manufacturers need to be in alignment with the FDA’s current policy and regulatory requirements on cleaning validation for reprocessing reusable medical devices including labelling instructions contained in 510(k) or PMA. Industry expert John E. Lincoln has great insights on how firms should develop cleaning validations, as well as insights on regulatory requirements for mobile medical applications.

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