PVC, PVDC, and More: Comparing Blister Packaging Materials for Optimal Drug Protection

It started with a humidity test failure.

A batch of pediatric antibiotics — packed for a tropical market — began showing signs of degradation after just four months. The QA lead gathered the R&D and packaging teams: “The formulation is stable,” she said. “It’s the packaging. Let’s dig in.”

The investigation pointed to the choice of blister material — a PVC base with basic foil lidding. It was cost-effective but couldn’t withstand the heat and humidity of Southeast Asia.

This isn’t a rare story.

Choosing the right blister packaging material is one of the most overlooked — yet mission-critical — decisions in pharma. It affects drug stability, patient safety, shelf life, and regulatory compliance. And with multiple materials available, from PVC to PVDC, Aclar, and Alu-Alu, how do you know what’s right for your drug?

Let’s walk through it like your team did — step by step, story by story.

The Building Blocks of Blister Packs

A blister pack has two main layers:

• The forming film — the plastic (or aluminum laminate) that creates the cavity
• The lidding foil — the seal that protects the product

The battle for protection is fought in the forming film. That’s where material science, not just marketing, determines success or failure.

1. PVC — The Familiar Workhorse

Used by the majority of generics manufacturers, PVC (Polyvinyl Chloride) is simple, efficient, and economical. It’s like a basic raincoat — enough to cover the drug, but not built for storms.

When It Works:

• OTCs and vitamins
• Stable generics that don’t fear moisture

When It Fails:

• Tropical climates
• APIs that degrade with oxygen or humidity

“It’s cheap. It’s transparent. But it’s not a barrier — it’s a shell.”

2. PVDC-Coated PVC — The Next-Level Upgrade

Add a PVDC coating, and suddenly, PVC gets an armor upgrade. Moisture protection improves 5 to 10 times — a balance of barrier and cost.

It’s the go-to material for companies exporting to Southeast Asia or Latin America.

Strengths:

• Retains transparency
• Works on existing thermoform lines
• A good choice for moderately sensitive molecules

Watch-outs:

• Coating uniformity matters — a poor supplier ruins everything
• Still not ideal for long-term or ICH Zone IV shelf life goals

3. PVC + Aclar® (PCTFE) — The Premium Guardian

Think of Aclar as the VIP suite of blister materials. Built from PCTFE, it offers ultra-low permeability to moisture and oxygen.

Why It’s Loved:

• Biotech and specialty drugs
• Transparent despite high protection
• Multiple thickness options (tailor barrier to shelf life)

The Challenge:

• Expensive
• Requires reliable sourcing

“We used Aclar for a sublingual cancer therapy. Shelf life doubled. So did peace of mind.”

4. Alu-Alu (OPA/Alu/PVC) — The Impenetrable Fortress

When visibility doesn’t matter but barrier strength does, cold-form Alu-Alu wins. With zero light and moisture ingress, it’s the gold standard for high-risk molecules.

Use It For:

• Hormones, antibiotics, oncology meds
• Export markets with heat, humidity, or long shipping cycles

Drawbacks:

• Opaque — no visual check
• Slow forming speeds and bulkier packs

Material Face-Off: Who Wins Where?

The Malaysian Case Study

That pediatric antibiotic we opened with? The team moved from PVC/PVDC to PVC/Aclar. Why?

• Shelf life goal: 12+ months in tropical ICH Zone IV
• Need for transparency: Pediatric adherence matters

Result? Zero degradation after 12 months. Packaging saved the drug.

How to Choose: A Material Checklist

Ask these before choosing your forming film:

• How moisture- or oxygen-sensitive is the API?
• What shelf life is required? 6, 12, 24, or 36 months?
• Which countries are you selling into?
• Does the product need to be visible?
• Can your line handle cold-forming?
• What % of your COGS can go to packaging?

Final Thoughts

In pharma, packaging isn’t a box. It’s a barrier, a promise, a shield.

PVC works — until it doesn’t. PVDC is better — until the market demands more. Aclar and Alu-Alu raise the bar — but also your costs.

The right choice is the one that aligns with your molecule’s vulnerabilities, your market’s realities, and your business’s priorities.

💬 Pro Tip: Don’t just ask “what’s cheapest.” Ask: “What could fail — and how much would that cost us?”

Still deciding? Use our Material Selection Checklist →

FAQs (Frequently Asked Questions)

What are the main materials used in blister packaging for drug protection?

The primary materials used in blister packaging include PVC (Polyvinyl Chloride), PVDC-coated PVC, PVC combined with Aclar® (PCTFE), and Alu-Alu (OPA/Alu/PVC). Each offers varying levels of moisture and oxygen barrier properties suitable for different pharmaceutical needs.

When is PVC considered an appropriate blister packaging material?

PVC is ideal for over-the-counter drugs, vitamins, and stable generic medications that are not sensitive to moisture or oxygen. It is widely used due to its familiarity and cost-effectiveness but may fail in tropical climates or with APIs that degrade easily.

How does PVDC-coated PVC improve upon regular PVC in blister packs?

PVDC coating enhances PVC by providing better moisture and oxygen barrier properties while retaining transparency. It works on existing thermoform lines but requires uniform coating quality to ensure optimal protection.

What advantages does combining PVC with Aclar® (PCTFE) offer in blister packaging?

PVC combined with Aclar® provides premium protection with excellent moisture and oxygen barriers while maintaining transparency. This combination is favored for biotech and specialty drugs but comes at a higher cost and requires reliable sourcing.

In which scenarios is Alu-Alu blister packaging preferred despite its drawbacks?

Alu-Alu blister packs are chosen when maximum barrier strength against moisture, oxygen, and heat is essential, such as for hormones, antibiotics, oncology medications, and export markets with challenging climates. However, they are opaque, bulkier, and slower to form.

What factors should be considered when choosing the right forming film for blister packaging?

Key considerations include the drug's sensitivity to moisture and oxygen, required transparency for visual inspection, climate conditions where the product will be stored or transported, manufacturing capabilities, cost constraints, and the need for regulatory compliance to ensure optimal drug protection.

Additionally, the compatibility with the chosen packaging material, such as the blister tray or card, should also be evaluated to prevent any issues like adhesion or delamination. Furthermore, the ease of use during the packaging process, such as compatibility with automated machinery or manual handling, should be taken into account to ensure efficient production. Lastly, the environmental impact of the chosen forming film material should not be overlooked, as sustainable packaging solutions are increasingly prioritized in today's market.