Biodegradable Polymers in Medical Devices: Testing, Applications, and FDA Issues

Biodegradable polymer devices must show two things: what leaches now and what degrades later, and that both are safe at real‑world exposure. Build a risk‑based plan around ISO 10993‑18 for chemical characterization, ISO 10993‑13 for polymer degradation products, ISO 10993‑17 for tox thresholds, and ISO 10993‑6 implantation, then confirm in‑vitro degradation and strength retention with ASTM F1635.

FDA’s current ISO 10993‑1 guidance expects that plan, plus proof the device keeps its strength through the clinical “critical window.”

Show what breaks down, how fast, and that the byproducts and performance are safe for patients. Tie your testing to ISO 10993‑13/17/18, do implantation, and run ASTM F1635.

What does a “biodegradable polymer device” mean

It’s a device meant to safely break down in the body, so removal surgery isn’t needed. Common materials are PLA or PLLA, PLGA, PGA, PCL, and PDO. They serve in:

sutures
fixation
drug depots
stents
tissue scaffolds

These polymers degrade over weeks to years. You control the timeline with choices like lactide:glycolide ratio, molecular weight, crystallinity, and end‑group capping.

Link your team to a quick overview with our biocompatibility testing for medical devices. It explains contact types and how duration drives endpoints.

Pick the right applications, then the right risks

Use tissue contact and time in the body to drive your test plan. Short‑term sutures don’t face the same risks as long‑term fixation or blood‑contact depots. FDA’s ISO 10993‑1 guidance formalizes that risk logic.

For blood‑contact devices, add hemocompatibility testing. Many teams start with hemolysis, then layer coagulation, platelet activation, and complement activation.

For any implant, plan ISO 10993‑6 implantation to read the local tissue response. Bone and muscle sites are available for orthopedic use.

Build your degradable‑device test plan the smart way

Start with chemistry, translate to tox, confirm with biology, and verify degradation and performance over time.

Do ISO 10993‑18 chemical characterization to understand extractables and leachables. Use VOC, SVOC, NVOC, and elemental analysis to cover the chemical space.

Quantify polymer breakdown with ISO 10993‑13 tests designed for clinical realism. Identify and measure degradation products under simulated use and accelerated screens. Summarize the compounds, expected exposure, and controls.

Convert data to patient risk with ISO 10993‑17 toxicological evaluation. Align AETs, limits, and margins of safety with device exposure.

Confirm biology where it matters. Start with cytotoxicity (MEM elution), then add irritation/sensitization and genotoxicity (AMES, MLA), and mouse lymphoma assay as the risk profile demands. Finish with implantation for local tissue effects.

Use a Biological Evaluation Plan (BEP) to pre‑agree the scope, and close with a Biological Evaluation Report (BER) that ties chemistry → tox → biology into one narrative.

Degradation and strength retention you can defend

ASTM F1635 gives you a repeatable way to track mass, molecular weight, pH, and mechanics over time in physiologic media. Use it to justify resorption claims and label your strength‑retention window.

Practical steps include:

choose timepoints that bracket the critical window
run GPC for MW and monitor mass loss
pair with fracture or pullout tests when load matters
record morphology shifts over time

If packaging or temperature could affect kinetics, add accelerated aging per ASTM F1980 and confirm with real-time where needed.

Sterilization and shelf life: the absorbables gotchas

Sterilization and aging can shift molecular weight and mechanics in degradable polymers. You must show that your process keeps the device safe and effective.

EO is often best for delicate polymers. If you use it, verify EO and ECH residuals to ISO 10993‑7, and plan degassing time in your schedule. The FDA has a hub on sterilization methods and is pushing innovation while balancing supply risk.

Know the policy backdrop. EPA’s 2024 rule tightens EtO emissions for commercial sterilizers. It aims to cut cancer risk while keeping devices flowing; your supplier may change controls or timelines.

Radiation can reduce MW or change crystallinity in PLA/PLGA, which can speed degradation. Some teams mitigate with low‑temperature or inert‑atmosphere gamma, but you still need pre-/post-GPC and mechanics.

For final packaging and shelf life, use ISO 11607 package validation and an accelerated aging plan that doesn’t over‑accelerate beyond what you can justify.

What the FDA expects in 510(k) or PMA files

FDA wants a risk‑based plan per its ISO 10993‑1 guidance, clear links from chemistry to tox to biology, and proof that your device holds performance until it is safely resorbed.

Submission checklist:

ISO 10993‑18 chemical characterization and E/L profiles
10993‑13 degradation product ID/quant under realistic conditions
10993‑17 tox evaluation with AETs and MoS
endpoints by contact and duration (cyto, irritation, sensitization, genotox, systemic tox, hemocompatibility, implantation)
ASTM F1635 degradation and strength retention
sterilization validation with EO residuals or radiation impact data
packaging ISO 11607 and aging plan

If you change polymer grade, MW, sterilization, or coating, revisit your plan and update the BEP and BER before submission.

Engineering tips that prevent rework

Lock your sterilization, packaging, and degradation protocol early. Screen materials with fast in‑vitro degradation and chem‑char before long studies.

Quick wins

tune lactide:glycolide ratio, MW, and crystallinity to hit the resorption window
monitor GPC, mass loss, pH, and mechanics per F1635
control residual moisture and solvents
plan AET/reporting limits with toxicological evaluation before you run chemistry
always compare pre-/post‑sterilization data for PLA/PLGA devices

Useful read when scoping tests: Understanding ASTM tests in medical device biocompatibility.

What engineers are asking online?

Engineers on forums often ask about PLGA chain scission after gamma, how many timepoints to use in F1635, how to schedule EO residual testing, and how “real” to make 10993‑13 media. Those are fair questions and solvable.

What we see again and again

gamma or e‑beam lowers MW in PLA/PLGA, so do pre/post GPC and mechanics
pick F1635 timepoints that span the clinical strength window
schedule EO residuals early and plan degassing to meet ISO 10993‑7
choose 10993‑13 media and temperatures that reflect actual use

For each of these, the standards and studies support the best practices above.

FAQs

Which standards govern degradable polymer testing?

ISO 10993‑13 for polymer degradation products, 10993‑18 for chemical characterization, 10993‑17 for tox limits, 10993‑6/‑5/‑4 for biology, and ASTM F1635 for in‑vitro degradation and strength retention.

How do we prove degradation products are safe?

Identify and quantify them, estimate patient exposure, set limits with 10993‑17, and confirm tolerance with biology. Wrap it in a tight Biological Evaluation Report.

Does the sterilization method matter for PLGA or PLA?

Yes. Radiation can lower MW or change crystallinity; EO needs residual testing to ISO 10993‑7. Validate safety and performance both ways.

What does the FDA look for in submissions?

A risk‑based plan per its ISO 10993‑1 guidance, and evidence that your device performs until resorption is safe.

Work with NABI

If you need a turnkey path to approval, start with a Biological Evaluation Plan (BEP) that defines your endpoints early.

Run chemical characterization and toxicological evaluation upfront before you lock in long, costly studies. For implants, choose subcutaneous, bone, or muscle implantation sites aligned with clinical use.

Round it out with EO residual testing, hemocompatibility, and accelerated aging to prove safety and shelf life from every angle.

Phone: +1 407‑278‑6815

Email: contact@nabi.bio

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