Balancing act: Developing a child-resistant, senior-friendly blister

December 20, 2015

10 Min Read
Balancing act: Developing a child-resistant, senior-friendly blister

Pharmaceutical & Medical Packaging News staff

By Erik Swain, Senior Editor

When the Consumer Product Safety Commission (CPSC) revised its protocol requiring that drug packages be senior friendly as well as child resistant, blister package designers were faced with a challenge.

Many had previously sealed their packages very tightly to keep children out, not taking senior friendliness into account at all. Some blister packages will continue to be made that way, because the protocol allows a unit-dose package to pass the senior-friendliness test by being cut open with scissors, provided that the instructions call for it.

Mindful of senior frustration and child poisonings, blister makers are experimenting with new package designs that require cognitive skills to open them. Dosepak photo courtesy Westvaco.
 

But that solution will not suffice for other packages, whose compliance and barrier features could be compromised if allowed to be attacked with scissors. It will not work for the growing numbers of new drugs that must be packaged in blisters because of their high toxicity levels. In some cases, if a senior citizen skips a dose or stops taking the drug altogether because of frustration over the packaging, it could mean the difference between life and death.

As a result, there is a new wave of blister package designs whose opening features are using an entirely different set of parameters. Instead of relying on force—which stymies seniors as well as children—to get the package open, these designs accommodate certain qualities that seniors have but children do not, such as reading comprehension, the ability to follow a multistep process, and, to a lesser extent, dexterity.

It will be important for these designs to achieve their goals, says John Bitner, manager of packaging design and development for drugmaker Searle (Skokie, IL). "A number of people would like to see the blister be the preferred package," he says. "But until they address certain issues, the blister can never be the preferred package." A lot of seniors, he notes, have grown to hate all blister packages because of previous bad experiences with trying to open them. Consequently, many seniors don't even bother to try to figure out how to open a blister properly; instead they cut it open and put the drug in another container. If the blister was needed to show them when to take each dose or to protect the drug from moisture, heat, or light, its purpose has been defeated—and its child resistance is probably gone, too.

Peter Mayberry, executive director of the Healthcare Compliance Packaging Council (Falls Church, VA), agrees that industry urgently needs a senior-friendly, child-resistant blister.

"One of the biggest barriers to blister acceptance is public perception," he says. "In certain cases where a product has come out of a bottle and into a blister, not a lot of thought has been put into the blister design. When blisters are made inconvenient to open, it defeats the compliance purpose."

NEW DESIGNS

Efforts to design such a blister are still in the development stage, but 2000 should see the market debut of several new designs.

One design scheduled to debut commercially this year is the Dosepak from Westvaco (New York City). It features an inner blister sealed to an outer paperboard carton that provides child resistance through a locking mechanism that children don't seem to realize exists. The carton also has a tear-resistant laminate, because ripping is the most common way children try to get into a blister package.

Once the locking mechanism is released and the package is opened, the individual blisters are not difficult for seniors to open. In addition, says Westvaco's category manager Michael Hubble, the carton provides ample room for compliance-related information, and the paperboard is hard to dispose of because it is attached to the blister, meaning that the child-resistant feature and the labeling always remain.



The Envelope Package from algroup wheaton pharma center shelbyville opens without the use of force.

"We realized that blisters offer a certain level of child resistance, but at the same time, we heard a lot of complaints about peel-push blisters being too difficult for seniors to open," says Brad Jones, project engineer at Westvaco.

After several redesigns, Jones says, the package was able to pass the CPSC testing protocol without children gaining access to any pills, so it can be used for the most toxic drugs.

It also means that the package can be used in clinical trials, where the toxicity of a drug may still be unknown. It also "allows you to conduct clinical trials and to commercialize in the same package," says Westvaco's John Smit, market specialist—healthcare. "It's just a matter of changing the graphics."

Another design is the Slide Pack from Packaging Coordinators Inc. (PCI; Philadelphia). It looks like a regular blister on a folded card, but the pills can't be pushed out until one moves a sliding mechanism within the package. Sliding appears to be another activity that children can't do but seniors can.

The Slide Pack is also appropriate for drugs that treat chronic conditions as well as for the most toxic drugs, says Dan Gerner, president of PCI. It is also being touted for its portability.

Another company working on child-resistant, senior-friendly blister designs is algroup wheaton pharma center shelbyville (Shelbyville, KY). At a seminar held in June 1999 in Princeton, NJ, the company unveiled several concepts for blisters that would be complex to open but would not require force.

One, now called the Envelope Package, requires unfolding the package and pulling out a carton piece from the middle of it before the tablet can be pushed through. The piece also provides an extra billboard for marketing and compliance purposes. The package has attracted interest and is now about to go through test protocols, says Olivier Muggli, market development manager.

Three other designs are in earlier stages of development, while two have been dropped because of concerns that seniors would find them too complicated to open. "We've limited the scope to three or fewer movements until you reach the product," Muggli says. "Otherwise, people might not remember how to open it."

Reynolds Metals Co. (Richmond, VA), a provider of blister foils, presented a variety of concepts at the WorldPharm 99 conference October 27 in Philadelphia, including:

  • Clean Cut blisters with units that can't be peeled until separated from the blister. Each cavity's lidding is independent, so a break or tear in one cavity does not damage the rest.  

  • No Tear films that can't be torn by children's teeth and that are targeted for "scissors-only" packages.  

  • Bitpak paper with denatonium benzoate, a bitter substance. It is overcoated so it can't be transferred to the hands but remains saliva soluble. Not only will children be thwarted when they bite into the package, but they may associate the unpleasant experience with all blister packages and never try to bite into any again.  

  • The Break Tab, which requires a break in the perforation in the blister to expose a peel opportunity. It is targeted for fragile tablets and other products where the peel-push action won't work.  

  • A peel-peel-push blister, which is like a peel-push design, except that one must peel two layers to get to the medicine. In addition, Searle has come up with a peel-turn-push concept and has enlisted Reynolds to help develop it.

"The focus of these concepts is on cognitive ability," says Patrick H. Dent, technical coordinator—pharmaceutical and healthcare markets for Reynolds's Global Packaging Group. "Many seniors don't have the dexterity or strength to open conventional packages."

MATERIAL NEEDS

All of these projects require special material considerations, and material suppliers say they are being consulted on how best to implement them.

"The most critical thing we are asked about is heavier thicknesses for bite resistance," says Kevin Carter, technical service—pharmaceutical blister films at Klöckner Pentaplast of America Inc. (Gordonsville, VA). "We also have to consider the impact strength of the materials in relation to the perforations. You may need to have lower impact strength so the perforations tear more easily, but then you run the risk of the perforation fracturing into the cavity."

With designs that rely on peel access, Carter says, "you have to be sure that your heat-seal coatings are compatible with your seal surface, particularly PVdC (polyvinylidene chloride), which sometimes bonds too aggressively to peelable heat-seal coatings. One customer got to the product launch phase before they found that they couldn't open the package because of that."

Foils in these designs, says David R. Sciubba, healthcare sales manager for Hueck Foils LLC (Wall, NJ), need to be bite resistant for children but peelable enough for seniors. However, he says, "a lot of our experience has been that for a product launch with time sensitivity, industry falls back on the old standby, the peel-push design. We admit that it's not particularly senior friendly, and we are looking for something on the cutting edge. One of the biggest challenges blister packagers face is the protocol test itself, as some of us in industry believe that blisters are inherently child resistant in many ways."

TESTING DEVELOPMENTS

Although most of the rest of the world does not have child-resistant, senior-friendly protocols for nonreclosable packages along the lines of those in the United States, the European Committee for Standardization (CEN) is trying to develop them. If successful, they would form the basis of an ISO guidance document. Until now, many other countries have declared blisters inherently child resistant as long as the package is opaque so the pills can't be mistaken for candy.

In the interest of global harmonization, ISO may adopt a testing protocol similar to that of the CPSC. However, those familiar with the discussions say that there are several points of contention. For instance, some CEN and ISO members working on the project are opposed to testing with children, arguing that it encourages them to go home and play with drug packages.

Also, the Poison Prevention Packaging Act prevents the CPSC from dictating package designs, so industry must rely on field tests of each package. ISO, however, is looking to develop standards for the packages, which would enable it to specify, for example, the force and thickness of a given package and could allow mechanical tests to determine what meets the standard.

Muggli of algroup says that a solution can be reached. "The feedback I'm getting from colleagues who sit on the committees in Europe is that it's only a question of time, and the European regulation would not be very different from the North American one. In 5 to 10 years, the two markets will be very much alike, and that will help. More companies will be working on the issue, so there will be better ideas and better machinery, a bigger market to sell in, and lower prices."

Suzanne Barone, PhD, project manager of poison prevention for the CPSC, notes that the CPSC staff may revisit some issues with blister testing, particularly the provision that defines a failure as the child gaining access to one toxic dose or more than eight units, whichever is lower. They may also look at clarifying how to present the package to the child, among other issues.

BEYOND PROTOCOL

Bitner of Searle says, however, that a solution will only come when industry looks beyond passing the protocol.

Ironically, the senior citizens who have the most problems opening blisters are the ones who are exempt from the protocol test. They are the ones who contribute to the perception that no blister is easy to open and who are most likely to remove their drugs from the package and leave them unsecured. The test does not cover people older than 70, those who are illiterate or cannot see well enough to read the instructions, or those who are unable to open non—child-resistant packages because of arthritis or other reasons.

"If they can't read above a fourth-grade level, don't exempt them, but make the package so it will accommodate them, not eliminate them," Bitner says. "Healthy adults 50 to 70, as the protocol says, do not represent what it's like out there. Adults have the reason and logic to understand what to do if we give them a package they can use in their home. Right now, they don't realize the consequences of not using it properly. We have to educate them."

Gerner of PCI agrees that a major outreach effort needs to take place. "You can write all the regulations you want, but the problem is that none can be enforced when the patient takes the medication home and doesn't use the package as intended," he says. "Pharmaceutical companies, government, pharmacists, and physicians all need to educate the population."

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