Blister Packaging
Blister Packaging
Pre-formed plastic or foil cavities sealed to a flat backing — the standard format for pharmaceutical unit-dose, consumer goods, and industrial component packaging worldwide.
What Is Blister Packaging?
Blister packaging is a format in which a pre-formed plastic or foil cavity — the blister — is sealed to a flat backing material, enclosing one or more items in individual compartments. It combines product visibility, tamper evidence, individual unit containment, and efficient material use in a single structure.
Two fundamentally different construction methods exist. Thermoformed blisters heat a plastic web (PVC, PVDC, PP, PETG) to forming temperature and draw it into cavities using vacuum or pressure. Cold-form blisters (Alu-Alu) mechanically press an aluminium laminate into shape without heat, achieving near-absolute moisture and oxygen barrier for highly sensitive products.
Medical device application: Blister packaging is a primary sterile barrier system format for surgical devices, diagnostics, and implants. ISO 11607 validation requirements apply. See blister packaging for medical devices →
Thermoformed vs Cold-Form Blister
Thermoformed Blister
Heat-formed from PVC, PVDC-coated PVC, PP, or PETG. Good clarity and cost-efficiency. Suitable for products with moderate moisture sensitivity. Sealed to aluminium foil, coated paper, or peelable film lidding. Standard for pharmaceutical solid oral dose and consumer goods.
Cold-Form Blister (Alu-Alu)
Mechanically pressed from OPA/Alu/PVC or OPA/Alu/PP laminates without heat. Near-absolute moisture and oxygen barrier. Slower forming speed and higher material cost than thermoform alternatives. Required for highly moisture-sensitive APIs and hygroscopic pharmaceutical products.
Lidding Materials and Sealing
Lidding selection is determined by barrier requirements, sterilisation method, peel performance, and child-resistance obligations. Common options include hard aluminium foil (20–25 µm, push-through, pharmaceutical standard), paper/foil laminates (child-resistant or print surface), peelable films (food and medical applications), and Tyvek nonwoven (EO-sterilised medical device blisters).
Heat sealing is the standard method — temperature, pressure, and dwell time define the sealing window. Validated sealing parameters are critical in regulated pharmaceutical and medical applications. Reference: ASTM F88 seal strength · ISO 11607 (medical).
Frequently Asked Questions
Thermoformed blisters are heat-formed from plastic webs (PVC, PP, PETG) and provide good clarity at lower cost with moderate moisture barrier. Cold-form blisters mechanically press an aluminium-containing laminate without heat, achieving near-zero moisture and oxygen transmission — essential for highly moisture-sensitive pharmaceutical products. Cold-form is slower and more expensive but necessary for products where thermoform barrier performance is insufficient.
The standard pharmaceutical blister lidding is hard aluminium foil (typically 20 µm) coated with a heat-seal lacquer, providing push-through access and an excellent moisture barrier. Child-resistant blisters use a peelable paper/foil laminate requiring the paper layer to be peeled before the foil can be pushed through. For EO-sterilised medical device blisters, Tyvek nonwoven is standard, providing microbial barrier alongside gas sterilisation access.
Pharmaceutical blister sealing is validated under OQ/PQ methodology establishing the sealing window — the combination of temperature, pressure, and dwell time that consistently produces a conforming seal. Seal quality is assessed by seal strength (ASTM F88), leak detection, and visual inspection. In-process controls monitor sealing parameters at defined intervals. For medical device blisters, ISO 11607 Part 2 validation requirements apply — see MedicoPax.com for full detail.
For consumer goods — hardware, batteries, accessories — thermoformed PET or PVC blisters sealed to a printed paperboard card (face card blister) is the standard format. It provides product visibility, tamper evidence, and a large printable area for branding and compliance information. Where the product is pre-priced and sold from peghooks, a Euroschlitz or standard peg hole is incorporated in the card design.
For pharmaceutical blisters, EU Directive 2001/83/EC and ICH Q1A–Q1F stability guidelines govern packaging material selection and shelf-life validation. Food-contact blister materials are governed by EU Regulation 10/2011 (plastics) and specific regulations for other materials. Child-resistant packaging requirements are defined in ISO 8317 for reclosable and non-reclosable formats.
Need deeper technical detail?The full InnovaPax blister packaging guide covers forming, sealing, machinery, and regulatory considerations.
Read the full guide →