Conservative Exposure Predictions for Rapid Risk Assessment of Phase-Separated Additives in Medical Device Polymers

Area of Science:

• Polymer Science
• Materials Science
• Toxicology

Background:

• Medical device polymers can leach additives, posing potential health risks.
• Accurate risk assessment of leachables is crucial for patient safety.
• Current methods for leachable assessment can be time-consuming.

Purpose of the Study:

• To propose and validate a novel, rapid approach for risk assessment of leachables in medical device polymers.
• To utilize a diffusive transport model for conservative exposure estimations of additives.
• To compare model-predicted exposure values with toxicological thresholds.

Main Methods:

• A diffusive transport model was developed for phase-separated color additives.
• Sorption experiments were conducted to determine the diffusion coefficient and solubility limit of manganese phthalocyanine (MnPC) in PEBAX 2533.
• Model-predicted exposure values were validated against experimental extraction data.

Main Results:

• The diffusion coefficient (D) of MnPC in PEBAX 2533 was determined as (1.6 ± 0.5) × 10⁻¹¹ cm²/s.
• The matrix solubility limit (Cs) of MnPC was found to be 0.089 wt.%.
• Model-based exposure predictions were validated by extraction experiments, showing potential for risk assessment.

Conclusions:

• A diffusion model can provide rapid, conservative exposure estimates for additives in medical device polymers.
• This approach shows significant potential as a screening-level tool for assessing the risk of color additives and other small molecule leachables.
• The validated model aids in ensuring the safety and efficacy of medical devices.