Medical Device Chemical Characterization – Extractable Leachable Testing

Extractable and leachable testing is an important component in establishing the biocompatibility of a medical device. Historically, biocompatibility has been established primarily through in vivo testing. However, FDA and international regulators are placing an increasing emphasis on characterizing the chemical components of devices, including colorants and polymers, through extractable leachable testing using analytical chemistry methods. The resulting data is then used to provide a more complete picture of device safety.

The new approach of the ISO 10993-1 emphasizes the importance of risk management to drive the creation of a biocompatibility evaluation plan. Risk management should begin with evaluating the physical and chemical characteristics of the device and its intended use.

As a consequence, new medical device regulatory submissions, or submissions of material or colorant changes to existing devices, must include data thoroughly describing and characterizing the component materials of the device  – including the types of polymers and colorants.

Chemical assessment is described in two parts of ISO 10993: Part 18 (Chemical Characterization of Materials) gives information about generating extractables and leachables data and Part 17 (Establishment of Allowable Limits for Leachables Substances) talks about establishing safety limits for leachables.

ISO 10993-18 – Medical Device Extractables and Leachables

Certain classes of device require a more stringent chemical characterization study. These studies, also known as device extractables and leachables studies, follow ISO 10993-18 testing methods, and look at the types and amounts of chemicals that may migrate from a device during use. From this specific chemical profile, an overall risk assessment of the safety of the device can be created.

Chemical characterization studies can be complex and are meant to examine devices with a greater potential risk to users. Currently, the US FDA requires a device chemical characterization / extractables and leachables study with an associated toxicological risk assessment to be performed on any device with the potential for cumulative systemic contact of greater than 29 days. Long term implants would naturally be included, as would many short-term yet repeated-use devices.

Medical Device Chemical Characterization Services

Pacific BioLabs’ team of analytical chemists can work with clients to determine the most appropriate extraction conditions and extraction protocols for device characterization. Extractions can be exhaustive, simulated-use or exaggerated. FTIR testing is often used to determine and initial chemical fingerprint. Detailed chemical structure can be studied using Mass Spectrometry. Leached or extracted residual solvents can be analyzed by GC and GC/MS. Parameters such as time, temperature, solvent choice, and nature of device will be considered. Trace and heavy metal analysis is conducted by ICP-MS. Other tests routinely performed include moisture determination by Karl Fischer, pH, conductivity, viscosity, and osmolarity.

PBL is also currently offering toxicological risk assessment reports in conjunction with chemical characterization studies through Gad Consulting.  Gad Consulting has operated for more than 22 years, providing drug and medical device toxicology consulting services.

Available Methods

  • Volatiles and Organics by GC, GC/MS
  • Headspace GC
  • Spectrophotometry by UV/Vis/FL
  • Identity/Concentration/Purity/Stability by HPLC
  • Heavy Metals and Elemental Analysis by ICP-MS
  • FTIR testing
  • Protein Content and Characterization
  • Size and MW characterization by SEC-LLS
  • Moisture Determination by Karl Fisher
  • Osmolarity Determination
  • Conductivity
  • pH
  • Polarimetry
  • Total Organic Carbon
  • Viscosity Measures
  • Instrumentation Details

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