Plasticizer Migration in Pharmaceutical PVC Rigid Films: Research and Control Strategies

PVC rigid films are widely used in blister packaging for tablets and capsules due to their clarity and formability. To improve flexibility during processing, plasticizers are often added—but these additives can migrate, posing risks to drug safety, stability, and regulatory compliance.

1. Why Plasticizers Are Used

Plasticizers like DOP, DEHP, and ATBC soften PVC for thermoforming. However, under heat or humidity, they may leach out and contact the drug, potentially altering its potency or compatibility.

2. Risks of Plasticizer Migration

• Drug contamination or degradation

• Incompatibility with APIs/excipients

• Non-compliance with FDA or EU phthalate restrictions

• Film deterioration over time

3. Migration Mechanism

Plasticizers diffuse from the PVC matrix based on factors like:

• Molecular structure and polarity

• Storage conditions (e.g., temperature, humidity)

• Drug contact duration

• PVC-plasticizer compatibility

4. Testing Methods

To assess migration risk, the following are commonly used:

• GC-MS: Quantifies trace plasticizers

• FTIR: Identifies chemical groups

• UV-Vis: Screens for known plasticizers

• Stability Studies: Simulate long-term storage per ICH guidelines

Standards such as USP <661.1>, <661.2> and EU 10/2011 provide regulatory benchmarks.

5. Control Strategies

✅ Choose non-phthalate plasticizers (e.g., ATBC)
✅ Use minimal effective concentration
✅ Apply barrier layers like PVDC or Aclar
✅ Store under controlled temperature/humidity
✅ Conduct early drug-packaging compatibility studies

Conclusion

Plasticizer migration is a controllable challenge in pharmaceutical packaging. By selecting safer materials, validating packaging compatibility, and complying with global standards, manufacturers can protect product quality and patient safety.