Healthcare product safety: Medical devices

This article provides an overview of product safety with regard to the development of a medical device. For information on this topic for drug development, please see Healthcare product safety: Drug development.

The product safety of a medical device is one of the primary questions to address in healthcare product development. Regulatory agencies worldwide are responsible to safeguard public health. No matter how effective a healthcare product is, if the company developing it cannot prove that its benefits (effectiveness) outweigh the risks (safety), the medical device will not receive regulatory clearance or regulatory approval. Product-related safety is also one of the major reasons for product recalls, label changes (for example, increased warnings) and licence withdrawals or suspensions for marketed medical devices.¹

Scientific evidence needs to be submitted to support product safety

During the regulatory review of a medical device, scientific evidence is submitted to support the product safety. Depending on its classification, evidence may come from non-clinical data (for example, bench studies), animal studies and/or clinical studies. Ultimately, the probable benefits should outweigh the risk of injury or illness from product use. Obviously, the safety of the medical device plays a major role in such benefit-risk assessment.¹

When developing a medical device, the amount and type of product safety information required will vary depending on factors such as what the device is as well as its classification, intended use and targeted jurisdictions. The information to support device safety may include, but is not limited to, the areas outlined below.

Risk management of medical device

Throughout the medical device lifecycle, establish, document and maintain an ongoing process for:

• Identifying hazards associated with your medical device
• Estimating and evaluating the associated risks
• Controlling these risks
• Monitoring the effectiveness of these controls

This process shall include risk analysis, risk evaluation, risk control as well as production and post-production information.²

Identify possible hazards with the device design under both normal and fault conditions, including those resulting from user/human error. Unacceptable risks should be reduced to acceptable levels via mitigations such as redesigning the medical device (for example, adding an alarm or changing the material), changing the manufacturing process, or including warnings or precautions in the product label.^1,2

Non-clinical testing

Non-clinical tests^1,3 may include:

• Chemical testing on the medical device composition and its components. Materials such as metallic alloys, plastics, natural or synthetic biomaterials, or composite materials should be of acceptable quality (such as medical grade instead of industrial grade) with no safety concerns. If applicable, the degradation profile and degradation mechanisms should be identified and their corresponding impact evaluated.

• Biocompatibility testing, which should be conducted in accordance with ISO 10993 Biological Evaluation of Medical Devices if the device or any part of it will come into contact with the human body. Biocompatibility testing is intended to reveal any potential for adverse events or allergic reactions and may be used to establish preliminary levels of toxicity. The number of tests (for example, cytotoxicity, sensitization, irritation, different types of toxicities) is selected based on the patient exposure to the device.^* The biocompatibility of the material used in the medical device is a particular issue for polymeric ingredients, degradable components, animal-sourced substances and novel materials. Additionally, the manufacturing process (such as sterilization) may affect the biocompatibility of the device and thus testing should be conducted on the finished sterilized device unless you can provide a justification not to do so.

• Sterility & stability—for details, please see the articles Sterilization: Healthcare products and Stability: Healthcare products.

• Animal tissue safety—if the device incorporates material of animal origin (such as collagen), provide information regarding the inactivation or removal of infectious/transmissible agents and the absence of infectious agents such as bacteria, fungi, yeast, mycoplasma and viruses. Provide also information (for example, a Certificate of Suitability) related to transmissible spongiform encephalopathies (TSEs).

• Medical equipment safety testing, which demonstrates your compliance with safety standards (for example, IEC 60601 series), helps show that your medical device poses no risk of:
  • Fire
  • Electrical shock
  • Burns or tissue damage due to contact with high-energy sources
  • Exposure to ionizing radiation
  • Physical injury due to mechanical hazards
  • Malfunction due to electromagnetic interference or electrostatic discharge

• Mechanical safety testing, which ensures the medical device (for example, an orthopedic device) is sufficiently strong to retain its integrity under conditions of normal wear and tear for its intended use.

Animal studies

If required, animal studies should be conducted in accordance with Good Laboratory Practices (GLP) using an appropriate study design. For instance, for an absorbable hemostatic device, animal testing may be required to evaluate and monitor complications such as infection, hematoma, coagulopathy or increased wound-healing time.⁴

Clinical data

Depending on the medical device classification, your product and the targeted jurisdictions, clinical evaluation and/or clinical trials may be required to evaluate the safety of the device in human use.

Medical devices: Product safety evaluations do not end

The safety evaluation of a medical device is an ongoing process and does not end with regulatory approval to market the healthcare product, or its clearance. Post-marketing activities related to monitoring the safety of the medical device may include:

• Medical-device reporting
• Post-approval studies
• Post-market surveillance studies
• Medical-device tracking
• Voluntary or mandatory recalls
• Handling of complaints
• Any necessary notifications, repairs, replacements or refunds¹

If the risk-benefit ratio changes with new safety evidence from post-marketing activities, the medical device label or design may need to change, or the product may even need to be withdrawn to protect user safety.

*The U.S. Food & Drug Administration (FDA) has issued a guidance document called Use of International Standard ISO-10993, “Biological Evaluation of Medical Devices Part 1: Evaluation and Testing.” It replaces #G87-1 #8294 [blue book memo]). In addition to the tests recommended in the ISO standard, the FDA has identified additional tests that may be applicable for your medical device. Consider these as you design studies for products that are intended for the US market.

Disclaimer

The information presented in these articles is intended to outline the general processes, principles and concepts of the healthcare product development lifecycle. Since regulatory requirements are ever-changing, it is current only as of the date of publication and not intended to provide detailed instructions for product development. Every healthcare product is unique and therefore so is its associated product development lifecycle. Specific advice should be sought from a qualified healthcare or other appropriate professional.
Published: October 17, 2012

References

1. DeMarco, C.T. (2011). Medical Device Design and Regulation. WI: Quality Press.
2. International Organization for Standardization. ISO 14971:2007. Medical devices – Application of risk management to medical devices.
3. Prutchi, D. & Norris, M. (2005). Design and Development of Medical Electronic Instrumentation: A Practical Perspective of the Design, Construction and Test of Medical Devices. NJ: Wiley-Interscience.
4. U.S. Food and Drug Administration. (2006, October 31). Draft Guidance for Industry and FDA Staff – Class II Special Controls Guidance Document: Absorbable Hemostatic Device. Retrieved July 11, 2012, from http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm071424.htm.