Medical devices, whether they’re as simple as disposable examination gloves or as complex as pacemakers, must be proven to be biocompatible before they can go to market. Biocompatibility testing is especially important for devices that are designed to deliver a drug or come into contact with human tissue. Healthcare professionals need to know that no compounds in their medical devices are going to cause harm to patients or change the effects of their treatment.

Medical device testing requirements, as defined by the FDA, vary depending on the device class and intended use. Certain devices must undergo extractables and leachables (E&L) testing to receive FDA premarket approval. E&L studies identify substances that could leave the device and enter the human body. Extractables are substances that can migrate from a contact surface under aggressive conditions, such as high temperature or long contact time. Leachables are substances that can migrate from the contact surface during normal clinical use. After identifying these substances, chemical analysts must quantify them and determine if any compounds are toxic.

E&L testing is a valuable process for medical device manufacturers, as it allows them to evaluate the safety of their devices without relying on in vivo studies.

When Are E&L Studies Necessary for Medical Devices?

Chemical analysts must carry out E&L testing for medical devices that will have either direct or indirect patient contact. Many situations require medical device manufacturers to conduct E&L studies. For example:

  • The device has the potential to be in contact with human tissue for more than 29 days. This applies to both long-term implants and devices that are repeatedly used for longer than 29 days.
  • The device could potentially allow leachables to enter the body through a drug product (this could be a concern with syringes, for example).
  • The device contains a material with known toxicities, but the material could be acceptable for the end use.
  • The device will have direct contact with circulating blood.
  • The device’s chemical leachables have the potential to contact reproductive organs, regardless of the duration of contact.

These are just a few examples of cases that call for E&L studies. The full requirements for E&L testing are laid out by ISO 10933.

Meeting Rigorous Testing Requirements

The primary goal of E&L testing for medical devices is to identify any compounds that could migrate from the device to the body, under normal or aggressive conditions. Because it can be difficult to predict what substances will be present in or on a medical device, chemical analysts must screen for as many compounds as possible. After identifying and quantifying the compounds, analysts must answer the question: Does exposure to any of these compounds affect the patient’s safety?

There are many variables involved in E&L studies, and there are no clear step-by-step instructions for testing laid out by the FDA or ISO 10993 standards. This type of testing may seem intimidating to medical device makers, but fortunately, independent chemical analysis laboratories can conduct E&L studies on behalf of these manufacturers. Avomeen’s Ph.D. chemists regularly help manufacturers identify and quantify extractables and leachables, validate their analytical testing methods, and determine if medical devices are biocompatible.

Conducting E&L testing on new medical devices isn’t just something manufacturers need to do to satisfy FDA requirements; it’s essential to ensure the safety of the patients who will be using those devices. Contact us to get a quote for E&L testing services.