Pharmaceutical Blister Packaging: Benefits and Applications

Considering the sensitivity of pharmaceutical products to environmental factors, appropriate packaging is necessary to ensure the product retains all its qualities before the intended patient finally uses it. Over the years, various packaging technologies have been developed and employed in the pharmaceutical industry.

The first packaging materials used for pharmaceutical drugs were clay, natural fibers, stoneware, paper, and animal hides. Over time, these materials were replaced by glass bottles and ampules. After the invention of plastic in the 1900s, glass was replaced by plastic. Even today, most pharmaceutical products come in plastic packaging because it is versatile, lightweight, durable, and non-reactive with almost all medications.

From simple plastic bottles to plastic and aluminium blister packs, plastic packaging is used in various forms to protect pharmaceutical products. This article discusses one such plastic packaging that we, today, are most familiar with: blister packs.

What is Blister Packaging?

Pharmaceutical blister packaging, commonly known as blister packs, comprises pre-formed cavities or packets usually made from thermo-formed plastic and backed by a paperboard, aluminium foil, or a plastic sheet. The plastic cavities and backing are sealed via heat bonding to secure the product inside the cavities. Blister packs are used to package pharmaceutical products, consumer goods, and foods sensitive to environmental factors like humidity and contamination. However, blister packs are most commonly used in the pharmaceutical industry for tablets, pills, and capsules.

How is Pharmaceutical Blister Packaging Made?

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Pharmaceutical blister packaging is made via a multi-step process. While the exact manufacturing process depends on the materials used and application, here is a basic overview of the manufacturing process of blister packs:

Step 1: Material selection

The first step is material selection. Plastic films are used for thermoforming processes. Generally, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC)-coated PVC, or polyethylene terephthalate (PET) are used in the thermoforming process. Aluminum foils are used for cold-forming processes. The lidding or backing material used is most typically an aluminum foil.

Step 2: Forming blister cavities

In the thermoforming process, the plastic film is heated to a specific temperature (depending on the film material) to make it malleable. Then, the heated film is shaped into cavities of desired sizes using vacuum/pressure molding.

In the cold-forming process, the aluminum foil is directly pressed into a mold to form cavities. Only mechanical force is used to form the cavity-like shape on the aluminum foil, without any heat, as this preserves the properties of aluminum.

Step 3: Filling the cavities

The formed cavities in the plastic or aluminum foil are then filled with the drug. Most often, tablets, pills, and capsules are filled in pharmaceutical blister packs. All cavities are filled using automated systems to ensure there is no human contact and contamination.

Step 4: Sealing

After the cavities are filled, the backing or lidding material (i.e., aluminum foil) is sealed using heat and pressure. The sealing process is also automatic to ensure the packaging is airtight and even.

Step 5: Final touches

Once the sealing is complete, the sealed strips are cut into individual blister packs with the desired number of tablets, for example, 8×2 and 4×4. Perforations are added so that individual doses can be easily separated. The individual blister packs are labelled with branding information, packaging date, expiration date, and any other necessary information. Finally, they are inspected for deformities, missing tablets, and improper sealing before being boxed and distributed.

Over the years, pharmaceutical blister packs have become the most popular method of packaging materials. Of course, this is because of their numerous benefits.

Benefits of Blister Packaging

Here are some of the most common benefits of blister packaging:

Maintains product integrity

Blister packs can maintain the quality and efficacy of the product once it is packed. The airtight seal placed on the pharmaceutical product ensures that the product is not exposed to any environmental factors and remains under controlled conditions at all times. Hence, the pharmaceutical company can deliver their product to the patient without worrying about damage during transportation or storage.

Easy dosing

Because each pill or tablet is individually packed, the patient can consume the correct dose without removing too many products from the packaging. Hence, the remaining pills are not contaminated before they are consumed. The patient and caregiver can also easily figure out how many doses have been consumed by simply counting the number of empty cavities in the strip.

Tamper-proof packaging

The design of blister packs is quite simple, as you’ve gathered from the images shown above. However, this design also makes it very clear whether the package has been tampered with. Because each strip contains a continuous aluminium foil on the back and an unbreakable plastic sheet on the front, there’s only one way to get it out (break the aluminum foil for the tablet you want to consume). If the seal of any cavity is broken or cracked, it’s clear that the strip has been tampered with.

Inexpensive

Pharmaceutical blister packaging is inexpensive. As discussed in the previous section, the manufacturing of this material does not require any sophisticated materials, making the actual manufacturing process cheaper than that required for other packaging types like bottles. Furthermore, individual strips of blister packs are quite lightweight and, hence can be easily transported.

Prevents accidental misuse

Despite the simple design of blister packs, a specific action is required to open the cavity to access the product. To adults, this might seem relatively simple, but it prevents accidental consumption by children, who cannot easily cut the backing to access the drug. When the front cover is pulled away from the backing, individual pills do not all fall out of their cavities. Instead, they remain in the plastic cavity, which also prevents accidental ingestion by children.

These benefits of blister packaging make it an exceptional choice for packaging pharmaceutical products. There are many blister packaging applications.

Applications of Blister Packaging

Here are some common blister packaging applications:

• Pharmaceutical industry: Blister packing technologies are commonly used for packing over-the-counter medications and single-dose medications. They are used for the packaging of most tablets, pills, and capsules as they guarantee product quality and non-tampering during transportation.
• Consumer goods: Other types of blister packs are also used to package toys, hardware, and electrical items. However, instead of aluminum backing, cardboard or paperboard backings are used. The plastic is usually transparent so that the consumer can visually inspect the product before purchasing it.
• Foods: While blister packs are not very commonly used in the food industry, they are also used for some common food products like Jell-O and Lunchables. They are also used to separate individual chocolates or frozen cubes to ensure they retain their nutrition, quality, shape, and colour before consumption.

Bottom Line

Since their invention, blister packaging technologies have become the most trustworthy method of distributing solid-dose pharmaceutical medications. Today, blister packs are the go-to choice for packaging solid-dose medications as they ensure the product is not tampered with and has minimal movement during transportation. This, in addition to its other advantages like lightweight, low-cost, and safety, is the reason why, today, we’re very used to seeing pharmaceutical products in blister packs and can’t imagine other packing materials that were previously used, like paper, glass, and stoneware.

FAQs

1. What are the types of blister packs?

Blister packs are generally divided into thermoformed blister packs and cold-formed blister packs, as per the manufacturing process used to prepare them.

2. How can you tamper with a blister pack?

You cannot tamper with blister packs—that’s their advantage and selling point. Any tampering attempts are immediately identifiable, ensuring the patient receives the correct dose.

3. Can blister packs be recycled?

Blister packs are made of mixed materials (plastics and aluminium). Therefore, they cannot be directly recycled. While there has been research into recyclable blister packs, there are no options widely used in the market.