Printed Pharmaceutical Aluminum Foil

Printed pharmaceutical aluminum foil is a common packaging material, primarily used for aluminum foil packaging and blister packaging of tablets, capsules, powders and other pharmaceuticals. It is an ideal packaging material for widespread use in the pharmaceutical industry.

Material Structure of Printed Pharmaceutical Foil:

Aluminum foil for pharmaceutical packaging typically utilizes a multi-layer composite structure, primarily comprising:

– Base layer:

Common aluminum alloys such as 8011 (for PTP aluminum foil) and 8021 (for cold-formed foil), with a thickness range of 0.016-0.065mm. For example, PTP foil often uses 8011-H18 or O-finished aluminum foil, which offers excellent flatness and mechanical strength; cold-formed foil uses 8021-O-finished aluminum foil, which is suitable for stamping complex shapes.

– Printing layer:

Information such as the drug name, dosage, and batch number is printed on the foil surface using a gravure printing process. The ink must meet pharmaceutical standards to ensure zero migration risk.

– Protective layer:

Coated on the printed layer to protect the ink from abrasion and environmental corrosion. Materials such as nitrocellulose or synthetic resin are typically used.

– Adhesive layer:

The inner side is coated with hot-melt or solvent-based adhesive for heat sealing with PVC/PVDC rigid films. The heat seal strength must be ≥7.0N/15mm (PVC) or ≥6.0N/15mm (PVDC).

Based on the application scenario, printed pharmaceutical aluminum foil can be divided into the following categories:

– PTP aluminum foil (blister packaging):

For solid dosage forms such as tablets and capsules, with a thickness of 0.016-0.04mm.

– Cold-formed aluminum foil:

Suitable for high-end pharmaceuticals, providing enhanced barrier properties and puncture resistance, with a thickness of 0.04-0.065mm.

– Tropical aluminum foil (aluminum-plastic-aluminum composite):

For use in high-humidity environments, the outer layer of aluminum foil further enhances moisture resistance.

Physical Protection of Printed Pharmaceutical Foil:

– Excellent Barrier Properties

Aluminum foil thickness typically ranges from 0.005-0.2mm, with a barrier rate of nearly 100% for oxygen, water vapor, and light. For example, double-zero foil (thickness less than 0.01mm) can be used in blister packaging to effectively prevent medications from moisture absorption, oxidation, or photolysis. Experimental data shows that aluminum foil packaging can extend the shelf life of light-sensitive medications to over three years.

– Reliable Sealing

Through heat-sealing technology, aluminum foil can be laminated with materials such as plastic and paper to create airtight packaging. For example, PTP (pressure-permeable aluminum foil) laminated with PVC rigid film allows patients to press the foil to release the tablet when taking medication, ensuring a tight seal and facilitating ease of use.

– Strong Shape Adaptability

Aluminum foil can be processed into rolls and sheets to suit the packaging needs of solid medications (tablets, capsules), liquid medications (oral solutions), and powdered medications. Rigid and semi-rigid aluminum foil can be molded into shallow trays or cups for packaging frozen medications, offering efficient heat transfer and rapid freezing.

Chemical Stability of Printed Pharmaceutical Foil:

– Inert and Non-Reactive Materials

Aluminum foil is chemically stable and does not react with medications. Even with prolonged contact with acidic or alkaline medications, it will not release harmful substances, ensuring drug purity.

– Multi-layer lamination technology enhances protection.

Aluminum foil, when laminated with plastics (such as PE and PVDC) and paper, forms a multi-layer barrier. For example, PVDC-coated aluminum foil further enhances barrier properties and is suitable for pharmaceutical packaging in high-humidity environments.

Process Adaptability of Printed Pharmaceutical Foil:

– Mature Printing Technology

Aluminum foil can be printed on a surface using gravure and flexographic printing techniques to clearly display information such as the drug name, ingredients, and directions and dosage. Some companies have achieved 12-color printing, enhancing packaging aesthetics and transparency.

– Flexible Secondary Processing

Aluminum foil can be embossed, coated, and gluing to enhance packaging functionality. For example, embossed aluminum foil is used for branded packaging to enhance product display value, while coated aluminum foil improves friction properties and facilitates operation on automated packaging lines.

– Common Customization Services

Pharmaceutical aluminum foil suppliers offer customized services for specifications, thickness, and printed content.

Performance Standards and Testing:

Pharmaceutical aluminum foil must comply with multiple national standards and industry specifications. Core indicators include:

– Barrier Performance: Water vapor transmission rate ≤ 0.5g/m2/24h, oxygen transmission rate close to zero, ensuring that pharmaceuticals are protected from moisture and oxidation.

– Pinhole Density: ≤ 1 pinhole per square meter with a diameter of 0.1-0.3mm. Pinholes with a diameter greater than 0.3mm are not permitted.

– Mechanical Properties: Burst strength ≥ 98kPa (PTP aluminum foil) or ≥ 200kPa (cold-formed aluminum foil), tensile strength ≥ 98MPa.

– Chemical Safety: Heavy metal content ≤ 5.5ppm, fluorescent materials must not be in the form of flakes, and leachables testing must comply with pharmacopoeial requirements.

– Printing Quality: Clear text and graphics, overprint accuracy ≤ 0.1mm, and ink adhesion tested with 3M tape to ensure no detachment.

Printed aluminum foil packaging has expanded beyond traditional tablets and capsules to include liquid medicines (such as oral solutions), medical devices (such as catheters), and biological products (such as vaccines). Multi-layer composite aluminum foil bags excel in packaging traditional Chinese medicine granules and probiotics, providing both moisture-proof and light-proof performance.