Mono PP Replaces PVC for Pharmaceutical Blisters

What most stood out to me when I had a chance to interact with a sample blister pack made from PharmaGuard polypropylene (PP) was how easy it was to push the pill through the lid. It surprised me so much that I had to immediately do it again to see if it was a fluke. It wasn’t.

While product manufacturer Südpack Medica AG does tout this easy-open feature, the company focuses on the sustainability and production benefits. There are plenty of those too.

But I mention the ease of pushing a tablet out of a blister because there is such a need for more of this. The older I get, the more drugs I seem to need (unfortunately). Unit-dose packaging does help with medication compliance, a necessary aid as memory fades with age, too.

Of course, I’m not alone in needing more meds as I age. And research consistently shows that easy-open packaging is near or at the top of consumers’ wish list — at any age and for any product.

But a pleasant user experience is just one of several benefits of this new material that Pieter van Gool, Business Development Manager for Südpack Medica AG, told me about. The other benefits are:

• Sustainability: the mono material is recyclable or recycle-ready;
• A wider sealing window offers production flexibility;
• Low shrink properties enable a smaller footprint;
• Moisture barrier protects sensitive products.

Let’s look at each benefit separately. But first a few more details about the product.

Extrusion is done in one of the largest packaging film extrusion plants in South Germany. The thermoform material is compliant with the Food and Drug Administration (FDA) and global pharmacopeias. It is supplied in rollstock to customers around the world.

Since its introduction, PharmaGuard innovation has earned a WorldStar Award from the World Packaging Organisation, and was the winner of a Sustainability Award in the 2024 German Packaging Award competition.

van Gool also tells me that, while PharmaGuard is designed primarily for oral solid dose products (pills), the material can be customized to be applicable for other formats, including as a sterilizable tray for prefilled syringes and vials.

The transparent material is used for both top and bottom webs for prescription and over-the-counter pharmaceuticals and nutraceuticals used in parenteral and enteral care and lifesciences. Standard bottom webs are 300 microns (µm) thick; lidding is 90 microns. But other thicknesses are available on request.

Because of the material’s enhanced processability, blister cavities can be closer together vs. regular polypropylene, which minimizes the package’s size and overall environmental footprint.

Speaking of environmental footprint …

• Sustainability.

Polypropylene is a mature and quite large waste stream in Europe, where it is often collected and recycled with high-density polyethylene. The US still struggles to get #5 recycling numbers up but has seen positive activity here. But replacing polyvinyl chloride (PVC), globally, with a material less intrusive to the environment is a high priority for most companies.

Blisters made with PharmaGuard top-and-bottom webs are “recycle ready” and an eco-alternative to PVC or polyvinylidene chloride (PVDC) blisters. PharmaGuard, film and sheet, is also flourine-free, phthalate-free, and halogen-free.

Another point: Südpack Medica now has a controlling interest in Carboliq GmbH, a chemical recycling company using advanced conversion. This technology uses lower temperatures (below 400-degrees C.) than other advanced recycling processes, which saves energy and adds to the sustainable footprint.

van Gool tells me the company is piloting a program where Carboliq is handling Südpack Medica’s post-industrial waste. Carboliq’s Circular Liquid Resource (CLR) product, for example, is in accordance with REACH regulations and establishes proof of sustainability through the ISCC-Plus certificate.

According to the company’s literature: “A life cycle assessment conducted by Sphera has proven that the packaging concept is associated with a greatly reduced climate impact (in CO2-eq) of up to 47% as well as lower energy and water consumption compared to other commonly used PVC / PVdC and aluminum blister solutions.”

• Production flexibility.

Instead of a 5°C. thermoform window of traditional PP, PharmaGuard boasts a 15°C. thermoforming window. On top of that, it offers a wider sealing window as well.

It’s this wider thermoform window, wider sealing window, and low shrink that enables PharmaGuard PP to run on a lot of existing PVC lines. At interpack 2023, Südpack Medica proved this out by running PharmaGuard on a PVC tool on an IMA blister thermoformer. Ask to see the video!

“PharmaGuard’s shrink is so low and [the material] has such a wide thermoforming window that machine modifications are not needed,” says van Gool.

According to the product data sheet, PharmaGuard Form 300 (at 300 µm) has a melting point of 166°C. (+/- 4°C.), based on differential scanning calorimetry (DSC) test method DIN EN ISO 11357-3.

This may be too basic to mention, but consider, too, that sealing performance is optimized, as both webs are made from the same compatible material.

• Low and controlled shrink.

Production flexibility is further enhanced because the material’s low and controlled shrink ensures uniformity during thermoforming. Additionally, its wide thermoforming window means that the material’s behavior “results in high dimensional stability, which in turn guarantees a smooth packaging process, even on standard packaging machines.” This performance is reproducible from batch to batch.

Notable also is how this high dimensional stability eases subsequent packing into cartons. Other applications benefit as well — thicker thermoformed trays for prefilled syringes, vials, or ampules, for example, that need to withstand demanding downstream processes such as autoclaving.

• Barrier.

Polypropylene has a natural moisture barrier that PharmaGuard can leverage.

At a thickness of 300 micron, the bottom web has a water vapor transmission rate (WVTR) of ≤1 gram per meters squared a day per ASTM F1249 test at 38°C 90% RH.

At a thickness of 90 mils, the lidding offers WVTR ≤1.2 g/m² day, as at 38°C 90% RH per ASTM F1249.

Specs from the company explain: “The more evenly the material thickness is distributed in the cavity, the better the plastic’s barrier effect will be maintained. Since the barrier effect in polypropylene is created by the material itself and not by means of a comparatively thin coating, the measurement of the residual wall thickness provides more reliable information about the expected barrier effect.”

Other barriers — for oxygen and UV protection — can be added, too, upon request.