+1 (888) 794-0077

Developing Cleaning Methods for Successful Validation

Oct 12, 2020 | Medical Device Testing, Technical Expertise

When it comes to reusable devices, one of the many requirements in medical device development is providing detailed directions of the cleaning methods defined in the Instructions for Use (IFU). Validating those cleaning methods may seem to be a box to check before finalizing the technical files, but it carries more weight with regulators than may realize. By developing and writing the cleaning instructions within the IFU with the intent of passing the worst-case scenario in validation testing, you can help ensure that the process is robust and the documentation is on track for an efficient regulatory review.

Device complexity’s impact to testing design

When developing the cleaning instructions, consider the challenges presented to the cleaning process from the device’s geometry, the materials present, the different types of clinical contaminants and other potentially infectious materials (OPIM). Devices with complex designs – such as unique surfaces, absorptive/porous materials, or multiple lumens and small channels – may warrant a more comprehensive set of instructions for cleaning and, in turn, a more complicated construct to validation testing.

During validation testing, your partnering CRO will expose the device to a worst-case reprocessing scenario. This process includes subjecting the device to artificial soils, simulated use, reduced cleaning parameters and other challenging situations that reflect a worst-case clinical use. Lab specialists are looking for any gaps in the cleaning instructions that could arise during end-use.

A common pitfall with these instructions is a lack of robustness and clarity. For example, if a device’s cleaning instructions require the use of a brush, the user may be left wondering what the appropriate brush shape, size or material is to complete the job effectively. Providing crystal clear instructions – and even going further than you may see necessary – can minimize any guess-work and room for error.

If your device design becomes increasingly intricate, make sure your team reflects this evolution when writing the IFU cleaning instructions and planning adequate lead time to evaluate it.

“Clean” & the clinical setting

Before testing begins, determine the definition of “cleanliness” in relation to your device by deciding the testing analyte(s) that is the most clinically relevant to your specific product. Possible relevant analytes include protein, hemoglobin, and Total Organic Carbon (TOC), among others. The U.S. FDA requires that you test for at least two.[i]

In past years, the U.S. FDA accepted testing for log reductions in bacteria to demonstrate overall device cleanliness. More recently, the consensus shifted to standardize using more organically relevant analytes to assess the efficacy of the cleaning process. When remediating a device, consider testing specific analytes primarily and bacteria secondarily, as the combination is generally a more comprehensive representation of the bioburden your device will face. Make sure your testing partner is using the proper analytes to replicate your device’s clinical setting.

Fail-safes for successful testing

When completing validation testing, you shouldn’t be crossing your fingers and hoping your device passes. Enter the validation phase with confidence in your cleaning instructions by working closely with a testing partner during the development phase and using feasibility testing throughout this partnership to stay ahead of risks. Feasibility testing doesn’t have to be a critical path in device development. It can run on a parallel path without affecting the overall timeline.

These steps allow you to enhance and modify the cleaning procedure, so there are no surprises when your device reaches the validation stage. Your validation will look clean and comprehensive. In the long run, it may save you from extending timelines due to a failed validation.

IFU development is a tricky process, and it can be tempting to take shortcuts. Instead, work with a testing partner who knows the ins and outs of cleaning methods, worst-case scenarios and validation testing to make the process as smooth and seamless as possible. Don’t pull a partner in at the end just for validation – utilize their expertise throughout the IFU drafting process.

To learn more about how WuXi AppTec can help you with IFU development and validation testing, contact a representative here.


Established in December 2000, WuXi AppTec provides a broad portfolio of R&D and manufacturing services that enable companies in the pharmaceutical, biotech and medical device industries worldwide to advance discoveries and deliver groundbreaking treatments to patients. As an innovation-driven and customer-focused company, WuXi AppTec helps our partners improve the productivity of advancing healthcare products through cost-effective and efficient solutions. With industry-leading capabilities such as R&D and manufacturing for small molecule drugs, cell and gene therapies, and testing for medical devices, WuXi AppTec’s open-access platform is enabling more than 4,000 collaborators from over 30 countries to improve the health of those in need – and to realize our vision that “every drug can be made and every disease can be treated”.

For more information, please visit: http://medicaldevice.wuxiapptec.com/


[i] Guidance for Industry and Food and Drug Administration Staff, Reprocessing Medical Devices in Health Care Settings: Validation Methods and Labeling (2017)

Related Articles

White Paper: Unknowns are Unacceptable™

Unknowns are Unacceptable explains our risk-based approach to medical device chemical characterization and toxicological risk assessment.