Pharma Aluminum Blister Foil

Pharma Aluminum Blister Foil is a high-performance composite material specifically designed for pharmaceutical packaging, mainly used for blister packaging of tablets and capsules.

Pharmaceutical aluminum blister foil (PTP aluminum foil) is a high-performance material widely used in the packaging of solid pharmaceutical preparations such as tablets and capsules. Its core functions are to provide sealing, barrier protection, and ease of use.

Pharmaceutical aluminum blister foil is a key component of pharmaceutical packaging, aimed at ensuring product integrity, safety, and user convenience.

• Definition: Composed of multiple layers of materials with aluminum foil as the core layer, combined with other functional layers to form a packaging material with high barrier properties, sealing, and protection.
• Applications: Widely used for sealed packaging of pharmaceuticals, health supplements, and medical devices to protect the contents from oxygen, moisture, light, and microorganisms.

Aluminum blister foil is a key packaging material in the pharmaceutical industry. It provides excellent barrier protection and enables convenient "push-through" or "cold-formed" packaging.

Aluminum blister foil is the lidding material used to seal blister packs containing tablets or capsules. It provides a safe and hygienic barrier to ensure the stability of the medication before use. Its resistance to moisture, oxygen, light, and microorganisms ensures that sensitive medications retain their efficacy throughout their shelf life.

Structure and Composition of Pharma Aluminum Blister Foil

Pharma Aluminum Blister Foil uses a multi-layer composite structure, with a typical configuration including:

• ‌Protective Layer (OP)‌: Prevents oxidation of the aluminum foil and protects the printed layer from abrasion.
• ‌Printing Layer‌: Used for identifying pharmaceutical information; requires good adhesion and clarity.
• ‌Aluminum Foil Substrate (AL)‌: Typically made of 8011 alloy, with a thickness range of 0.016–0.04mm, providing core barrier performance.
• ‌Bonding Layer (VC)‌: Ensures heat seal bonding of aluminum foil with plastic rigid film (such as PVC).

Structure and Materials (Typical Layering)

Aluminum blister foil typically consists of multiple layers:

• Base Aluminum: Provides a barrier against moisture, oxygen, and light. Common alloys include 8011, 8079, and 1235, popular for their formability and strength.
• Heat Seal Lacquer: Applied on the inner (bright) side, bonds with plastic blister cavities (e.g., PVC, PET) during sealing. This ensures sealing integrity, which is critical for drug protection.
• Primer Layer: Enhances the adhesion of the heat seal lacquer and may contain dyes for branding. It is sandwiched between the aluminum and the lacquer to prevent interaction between pigments and the drug.
• Optional Laminated Layer: In some designs, the aluminum foil is laminated with paper, PET, or PVDC to enhance barrier properties or provide child-resistant features.

Pharma Aluminum Blister Foil Materials and Alloys

Common Alloy Grades for Pharma Aluminum Blister Foil

Soft/hard alloys 8011 and 8021: Widely used in cold-formed ("aluminum-aluminum") blister packaging due to their good formability and barrier properties.

Common Alloys

‌8011-H18 Aluminum Foil‌: A mainstream choice with both high mechanical strength (H18 temper) and moderate ductility, suitable for high-speed automated packaging.

Other optional grades: 8021 and 8079 aluminum foils, suitable for special scenarios (such as soft packaging).

Commercially pure alloys 1070, 1100, 1235: Used for non-cold-formed ("push-through") blister foils with thicknesses of 20–80 μm; these alloys offer excellent purity (>99.7% Al) and corrosion resistance.

Pharma Aluminum Blister Foil Chemical Composition

Alloy 8011 Composition

Aluminum alloy 8011 is the most common pharmaceutical blister foil grade, prized for its balance of mechanical strength and formability.

Alloy 8021 Composition

Alloy 8021 is designed specifically for cold‐formed pharmaceutical blister foils, delivering superior water‐vapor barrier and mechanical strength.

Alloy 8079 Composition

Alloy 8079 is often used in both pharmaceutical and food blister packaging, offering a fine‐grained structure for excellent drawability and high‐strength performance.

Types and Thickness of Pharma Aluminum Blister Foil

• Hard Aluminum Foil: Commonly used in Europe, with a thickness of approximately 25 microns. It allows easy "push-through" of the tablet while maintaining durability.
• Soft Aluminum Foil: Thicker and more flexible, requiring more force to open, offering child-resistant protection. Usually features perforations to prevent complete removal.
• Regional Differences: In the United States, thicker aluminum foil (up to 28 μm) is combined with peelable paper/PET laminates to form a "peel-push" design.

Pharma Aluminum Blister Foil Manufacturing and Lamination

Push-Through (Hard Foil)

Hard foil (approximately 25 μm) breaks cleanly with minimal force, allowing easy "push-through" of tablets. The sealing side uses a dual-coating system—primer and heat-seal lacquer—to ensure bonding strength and provide a printable surface.

Child-Resistant (Soft Foil)

Soft foil requires greater push-through force, enhancing child protection. Perforations along the seal line prevent foil detachment, while lamination with paper or PET further enhances protection.

Cold-Forming ("Alu-Alu")

Cold-formed foil is a multi-layer laminate composed of aluminum, nylon (oPA), and PVC. Dry bond lamination forms deep-drawn cavities, and no oxygen/moisture penetration occurs, making it ideal for highly sensitive drugs.

Physical and Mechanical Properties of Pharma Aluminum Blister Foil

• Thickness: Push-through foil thickness ranges from 20–80 microns; cold-formed foil ranges from 30–45 microns.
• Width: Roll width can reach up to 1 meter, with a tolerance of ±1 mm (≤ 800 mm) or ±1.5 mm (> 800 mm).
• Tensile Strength: Ranges from 60–110 N/mm²; for thickness > 0.03 mm, elongation is approximately 4%.
• Pinholes: Pharmaceutical aluminum foil must have zero pinholes per square meter to ensure defect-free barrier.

Key Properties of Pharma Aluminum Blister Foil

• Barrier Properties: Completely blocks oxygen, water vapor, and UV light, preventing moisture absorption and oxidative degradation of drugs.
• Heat Sealability: Forms a tight seal with plastic rigid films (PVC/PVDC); heat seal strength is controlled via adhesive coating amount and process parameters.
• Mechanical Performance: Heat-resistant, cold-resistant, corrosion-resistant, suitable for high-speed stamping and transportation environments.
• Easy Piercing: Foil with thickness ≤0.03 mm allows easy piercing for tablet retrieval.

Barrier Performance of Pharma Aluminum Blister Foil

Aluminum foil can completely block moisture, oxygen, light, and microorganisms, thereby maintaining product integrity during long-term storage. Aluminum foil is chemically inert, non-toxic, and can be supplied sterile, making it suitable for direct contact with pharmaceuticals.

Aluminum foil performs excellently in protecting pharmaceuticals:

• Moisture and Oxygen Protection: Water vapor transmission rate (WVTR) as low as <0.010 g/m²/day, oxygen transmission rate <0.005 cc/m²/day, ensuring long shelf life.
• Enhanced Barrier: PVDC-coated aluminum foil provides superior protection for moisture-sensitive drugs, while PET laminates enhance structural integrity.

Standards and Specifications of Pharma Aluminum Blister Foil

• International Standards: ISO 15378 (Quality Management for Pharmaceutical Packaging Materials), ASTM F2029 (Permeability Testing).
• Environmental Regulations: RoHS (Restriction of Hazardous Substances), REACH (Registration of Chemicals).
• Industry Certifications: ISO 9001 (Quality Management), ISO 14001 (Environmental Management).

Main Applications of Pharma Aluminum Blister Foil

Used in blister packaging for tablets, capsules, and medical devices, ensuring unit-dose protection and tamper evidence.

Key Performance Requirements of Pharma Aluminum Blister Foil

• Barrier Performance: Oxygen transmission rate ＜0.5 cm³/(m²·day), water vapor transmission rate ＜0.1 g/(m²·day).
• Seal Integrity: Heat seal strength ＞10 N/15 mm, ensuring no leakage.
• Puncture Resistance: Prevents damage during transportation.
• Biocompatibility: Complies with pharmacopeia standards (e.g., USP, EP) and ISO 10993 biological compatibility standards.
• Printability: Strong ink adhesion and abrasion resistance.

Packaging Formats of Pharma Aluminum Blister Foil

• Push-Through Blister Packaging: Tablets/capsules are pushed through hard aluminum foil; common in Europe and many other markets.
• Peelable/Peel-Push: Composite foil (aluminum + paper/PET) is peeled first, then the product is pushed out; commonly used in U.S. child-resistant designs.
• Alu-Alu Blister Packaging: Both base and cover are aluminum foil, providing maximum barrier protection for moisture/oxygen-sensitive drugs.

Printing and Customization of Pharma Aluminum Blister Foil

Blister foil is available in unprinted or fully printed (offset/gravure) versions for branding and regulatory information. Special primers and coating systems ensure ink adhesion without compromising barrier or seal strength.

Advantages and Limitations of Pharma Aluminum Blister Foil

Advantages of Pharma Aluminum Blister Foil

• Unmatched barrier protection, extends shelf life
• Non-toxic, sterile, tamper-evident
• Compatible with rotary and flat-type high-speed packaging machines

Limitations of Pharma Aluminum Blister Foil

• Higher material cost compared to pure PVC systems
• Recycling is challenging when using multi-layer laminated structures

Production Process and Quality Control of Pharma Aluminum Blister Foil

‌Production Process‌

Raw material inspection → Rolling (rough rolling, intermediate rolling, finish rolling) → Slitting → Annealing → Coating/Printing → Finished product packaging

• Aluminum foil pretreatment: cleaning and annealing to improve flexibility
• Lamination process: bonding each layer using dry or wet lamination methods
• Printing (optional): outer layer printed with pharmaceutical information
• Coating: inner layer coated with heat-sealing material
• Slitting: cut into rolls as required

‌Key Control Points‌

• ‌Pinholes‌: No pinholes with a diameter >0.3mm allowed; for pinholes 0.1–0.3mm, maximum 1 per square meter
• ‌Surface quality‌: Must be clean and flat, free from scratches, oil stains, and print peeling
• ‌Heat seal strength‌: Ensure blister seal integrity by adjusting sealing temperature, pressure, and time
• ‌Heat resistance of protective layer‌: No significant peeling after sealing at 200℃

Production and Customization of Pharma Aluminum Blister Foil

• Heat sealing process: Uses a combination of heat, pressure, and time to bond foil to blister tray. Customized lacquers ensure compatibility with different plastics (e.g., PVC, APET).
• Printing and branding: The matte (dull) side is typically printed with dedicated inks for branding, dosage information, or tamper-evident marks.
• Compliance: Meets FDA, USDA, and international standards for direct contact with pharmaceuticals, including non-toxicity and recyclability.

Key Considerations for Selection

• Material compatibility: Select appropriate foil alloy and coating based on drug sensitivity (e.g., PVDC for humid environments)
• Thickness: Balance barrier requirements and cost; 20–28 μm is the standard thickness, while thicker foil is suitable for peelable designs
• Manufacturer expertise: Work with ISO-certified suppliers that offer quality assurance and customization options