Industry News and Trends
6 February, 2025
What is the blistering process?
Blistering to the process of packaging products such as tablets, capsules, or other small items in packages called blisters. A blister is usually a plastic form with embossed compartments for individual products, covered with foil (e.g. aluminium) that creates a tight seal.
IOC has its own blistering lines for both hard capsules and softgel.
IOC offers certified packaging and blistering that meets standards ISO 22000, ISO 9001, GMP, Ghp, HACCP, supported by 17 years of experience.
What does a blister mean?
A blister pack is a type of tamper-evident packaging from which individual, sealed tablets are pressed through the foil to be taken. A blister pack is a form of secure packaging from which the patient presses individual tablets through the foil to take the medication.
In this article you will read about:
What is blistering?
Blistering is a technological process that involves packing products, usually small ones, in a specific type of packaging called blister (Ang. blister pack). This is one of the most popular methods of unit packaging, i.e. portioning and securing individual items of goods.
The blister packaging itself consists of two main parts:
Molded cavity: A transparent, rigid plastic “pocket” (e.g. PVC, PET) that is precisely fitted to the shape of the product.
Closing layers: A support usually made of cardboard, aluminum foil or other material, which is welded to the cavity, enclosing the product inside.
In everyday language, "blistering" simply means putting something in blisters.
A Comprehensive Guide to Blister Packing
Blistering is a technology for individually packaging products (most often tablets and capsules) by placing them in molded pockets (extrudates) and tightly sealing them with a protective foil. This process ensures hygiene, extends shelf life, and facilitates dosing.
Main functions and applications
- Protection (Barrier): Complete isolation of the product against moisture, oxygen, light (UV) and mechanical damage.
- Security: Tamper-evident guarantee – any attempt to extract the product leaves a permanent trace.
- Therapy control: Possibility of using calendar packaging (compliance packs), which makes it easier for patients to take medications systematically.
- Versatility: In addition to pharmaceuticals and dietary supplements, blisters are used in cosmetics, electronics (e.g. batteries) and the paper industry.
Production technologies
| Technology | Process flow | Application |
|---|---|---|
| Thermoforming | Heating the film (e.g. PVC, PET) to a plastic state and forming nests in it. | A fast, economical and effective solution for standard products. |
| Cold forming | Mechanical pressing of multi-layer foil (often with an aluminum core) without the use of heat. | Provides the highest possible tightness; ideal for products highly sensitive to moisture and light. |
Materials used
- Plastics: PVC, PVDC, PCTFE, PET – selected according to the required permeability and aesthetics.
- Aluminum foils and laminates: They guarantee an uncompromising protective barrier against environmental factors.
- Biodegradable materials: Future-proof, ecological alternatives currently under intensive research.
Quality, regulations and validation
For packaging to be eligible for the pharmaceutical market, the process must meet stringent GMP, ISO, and pharmacopeial guidelines. This requires a series of tests:
- Leak tests: Use of immersion, helium or bomb methods to verify blister integrity.
- Stability studies: Evaluation of the behavior of active substances under variable temperature and humidity conditions.
- Migration assessment: Guarantee that no chemical compounds from the material penetrate the product.
- Security (Child-Resistant): Designing mechanisms to protect against unauthorized opening by children.
Evolution and modern trends
Since the introduction of simple PVC packaging in the 60s, blister packaging has evolved steadily. Contemporary innovations include:
- Active packaging: The use of absorbent layers that actively absorb residual moisture and oxygen from inside the nest.
- Smart packaging: Built-in micro-sensors monitor storage conditions in real time.
- Digital integration: Equipping blisters with NFC or RFID modules that work with mobile applications to support therapy management.
- Sustainability and automation: Implementing modern, fast production lines and striving for full recycling of used materials.
A Global Approach to Marketing Blister Packaging Services
| Sector | Key marketing message | Main priorities |
|---|---|---|
| Pharmacy | Leadership status and trusted partner. | Security, strict compliance with standards, regulatory expertise, building trust. |
| Dietary supplements | Comfort and visual appeal (shelf appeal). | Ease of dosing, aesthetic packaging, brand differentiation from the competition. |
| Medical food | Combining medical precision with nutritional value. | Precise dosing, nutrient protection, intuitive while maintaining pharmaceutical standards. |
Blistering with International Organic Company
choosing International Organic Company, you gain a partner who combines pharmaceutical precision with organicknown for their cleanliness. Our comprehensive blistering services include:
- Safety and standards: Production under GMP rigour and full compliance with international standards.
- Dedication to products organicknown: Certified, free from harmful substances materials that emphasize the natural composition of the product.
- Stability and innovation: Hermetic packaging protecting against external factors and optional child-proofing.
- Distinctive design: High aesthetics supporting brand recognition on the store shelf.
- Comprehensiveness and flexibility: Short lead times, full traceability (serialization, QR codes) and expert advice at every stage of the project.
You invest in packaging that protects what is most valuable and raises the profile of your product. Contact usto see how we can strengthen your brand value.
Blister Packaging: Construction, Types and Production
Construction and components
Blister packaging (English) blister pack) is a packaging system consisting of two main elements. It is precisely tailored to the shape of the product, ensuring its visibility and protection.
- Blister pack: A molded, transparent cavity made of plastic (PVC, PET or PVDC).
- Base (cover): The material that closes the packaging, made of cardboard, aluminum foil or other material, also serves as a carrier of information and branding.
Types of blister packaging
| Packaging type | Design and features | Application |
|---|---|---|
| Welded to the cardboard (Face Seal Blister) |
Plastic blister heat-sealed directly to the cardboard backing. | An economical solution for standard consumer goods. |
| With full coverage (Full-Face Seal Blister) |
The blister covers the entire front surface of the box, stiffening the structure. | Products requiring higher aesthetics and resistance to damage. |
| Clamshell | Two-piece packaging connected by a hinge, closed with a snap or heat-sealed. | Electronics, heavier items; ensures maximum safety. |
| Trapped Blister | A blister placed between two layers of cardboard glued together. | Products that require more difficult opening and large advertising space. |
| Slide Blister | A blister with folded edges into which a cardboard backing is inserted. | Reusable packaging. |
| Pharmaceutical (Push-through) |
Aluminum backing pierced during single dose extrusion. | Medicines, supplements; guarantees sterility and portion control. |
Stages of the production process
- Blister formation: Performed by the method thermoforming (heating the plastic and vacuum forming) or cold forming (pressing of aluminum laminate without heat – for products sensitive to light and moisture).
- Product placement: Automatic or manual insertion of products into formed cavities on the production line.
- Welding: Bonding the filled extrusion to the backing material using high temperature and pressure.
- Cutting and perforation: Cutting finished packages from a sheet and optionally adding perforations to facilitate blister separation.
Key benefits
- Security: An effective barrier against moisture, oxygen, light and pollution.
- Tamper-evident guarantee: Traces of any unwanted opening are immediately visible.
- Dosage precision: Strict control of individual portions (essential in pharmacy).
- Shelf appeal: The transparent material allows the consumer to visually evaluate the product.
- The economy: High profitability in large-scale production.
IOC has been offering packaging and blistering services for over 15 years. Find out more. Contact us!
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Advanced Blister Technologies and Process Control (Q&A)
When is it worth replacing cold-formed blisters (Alu-Alu) with Aclar® foils in the context of OTR/MVTR and cost optimization?
Alu-Alu (Cold Form Foil) blisters offer an absolute barrier to gases and moisture (MVTR and OTR of 0). However, due to the physical inflexibility of aluminum, they require very gentle forming angles. This creates significant "dead zones" between cavities, increasing the blister format by 30-50%.
Thermoformable films made of polychlorotrifluoroethylene (PCTFE, e.g. Aclar®) provide barrier properties similar to aluminum, but allow for deep drawing with steep walls. This results in denser cavity packing, drastically reducing the size of individual cartons, and facilitates 100% visual inspection on the packaging line thanks to the full cavity transparency.
How to eliminate micro-leaks at welds and optimize the so-called Golden Welding Triangle?
Microleaks and channeling phenomenon (channeling) most often arise as a result of disturbances in Critical Process Parameters (CPP) in the welding station. These include: Temperature, Time contact (Dwell Time) and Downforce.
Microchannels form when the temperature is too low to fully activate the heat-sealable varnish (HSL) on the lidding film, or when the pressure is asymmetric due to the development of knurling rollers (rotary sealing) or plates (platen sealing). Another extremely common cause of leaks is contamination of the seal zone with tablet dust – this problem is solved by implementing dedicated vacuum systems (dedusters) and replacing brush feeders with vibratory tube feeders for highly abrasive products.
How can the phenomenon of blisters "curling" (bowing/rolling out) be eliminated using machinery after leaving the cutting station?
Curling is a nightmare on packaging lines, leading to constant jams in cartoner feeders. It's the result of stress asymmetry and differential thermal expansion between the base film (e.g., PVC/PVDC) and the cover film (hard aluminum). After leaving the sealing die and cooling, polymers shrink at a different rate than metal.
To eliminate this defect on the line, it is necessary to: precisely calibrate the unwinder brakes to perfectly equalize the web tension (web tension control), optimization and extension of the cooling plate zone (cooling plates) immediately after welding, as well as the use of a foil annealing station just before the die-cutting section.
Why does thinning occur in deep thermoforming and how can the cavity barrier be protected?
Due to the physics of polymer thermoforming, the bottom and lower radii of the cavity are the last to stretch, accumulating the most plasticized material (thinning to 70-80% of the base film thickness). This drastically reduces the barrier properties (MVTR) in a localized manner.
To protect yourself from relegation quality, it is necessary to apply mechanically assisted thermoforming (plug-assist)Special punches (usually Teflon) mechanically pre-press the heated foil into the die. They evenly distribute the material thickness on the side walls for a fraction of a second before the final blow-out occurs and the cavity is formed with compressed air.
CCIT and GMP Guidelines: Why is the industry forced to move away from the methylene blue test?
Traditional dye test (Blue Dye Test) is a destructive, probabilistic, and highly subjective method (it relies on the operator's visual inspection), which in practice often misses leaks below 15-20 µm. In accordance with contemporary guidelines, including USP <1207> and the updated GMP Annex 1, deterministic non-destructive testing (NDT) methods are becoming the standard. These include:
- Vacuum Decay: A method that non-invasively measures micrometric pressure drops (according to ASTM F2338). Fully sealed, tested blisters can be returned to the line.
- TDLAS (Headspace Analysis) Laser Spectroscopy: Advanced technology that non-invasively measures oxygen concentration or shielding gas loss inside each closed cavity – mainly used in the pharmaceutical industry for Alu-Alu blisters filled in a nitrogen blanket.
What technological challenges does the conversion to monomaterials (e.g. Mono-PP) pose to the blister machine due to the PPWR directive?
The ecological pressure to replace difficult-to-recycle laminates (e.g., PVC/Al) with polypropylene (PP/PP)-based structures is currently the biggest engineering challenge. Polypropylene (PP) is characterized by extreme narrow process window (thermal window) – the buffer between optimal plasticity and complete melting of the material is only a few degrees Celsius. Furthermore, PP exhibits enormous post-process shrinkage.
Its correct implementation requires the modernization of the blister machine: installation of advanced zone temperature controllers of heaters (PID), absolute use of supporting punches (plug-assist), covering the matrices with Teflon coatings to prevent sticking and complex redesign of the die-cutting tools (different material expansion profile).