7 questions you need answered to create the ideal diagnostic reagent blister

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The most obvious marker of a reagent blister product’s success is whether the test it helps perform provides fast, accurate results that guide patient care.

But clinical factors are only a small share of what ultimately determines the viability of reagent blister products. Developers might be less familiar with the design and manufacturing considerations that will establish how smoothly your products reach the marketplace.

The questions posed below are meant to help developers sharpen their understanding of those considerations earlier in the process to better leverage the expertise of reagent blister manufacturing partners.

Liquid blisters

What are your reagent’s chemical properties?

In  general, reagent blisters are made of foil layers backed by a polymer film which are welded together. Because different reagents have different chemical properties, they don’t always play nicely with blister materials.

Prior consultation with a manufacturer is essential to ensure that volatile, corrosive or degassed reagents are paired with materials that will not degrade in contact with the reagent over time.

J-Pac has developed a widely used reagent blister material set that has provided sufficient chemical resistance for the majority of our reagent blister customer applications. If that primary set won’t work, our team will then identify the ideal alternative materials that will yield better results.

Is your actuating force adequate for your blister design?

Two forces are required to successfully dispense reagents from blisters. The first is a one-time force required to puncture the blister. The second is a persistent force required to expel the reagent.

Obviously, an actuator must be strong enough to pierce a blister. But it also must be able to achieve the force required to continue expelling the reagent into the microfluidic consumable.

But the puncture force cannot be so strong that it overcomes the seal force created when blister layers were welded together. If the welded seal fails, reagent will escape into areas it’s not meant to go. This would invalidate a test and likely damage costly analyzing equipment.

Manufacturing partners are essential to choreographing the dance between blister design, manufacturing considerations and their relationship to actuating equipment.

Multiple dome shaped piercable reagent blisters

Have you accounted for reagent loss?

Once a blister is pierced, reagent is lost in transit from the blister to the analysis site.

Some reagent stays behind in the blister itself. Some remains in the reservoir below it. Some clings to the wetted surface of the microfluidic channel leading from the reservoir to its final destination.

Blisters must be designed with enough surplus reagent capacity to guarantee the appropriate amount reaches the analysis site.

What are your head space tolerances?

When a microfluidic reagent blister is filled, a meniscus is formed that prevents the blister to be 100%filled. Likewise, the film sealing process requires some fill tolerance to prevent fluid from migrating to the seal surface. J-Pac recommends designing for a blister fill volume of 80%, meaning the actual blister is larger than the amount of fluid dispensed. Many customers use the design of the microfluidic cards to handle gasses. If head space cannot be tolerated, J-Pac can provide a 100% fill through an alternate process that designers should recognize that is a slight premium to the conventional approach.

Head space is also related to the need for degassing as the gas within the head space will react with the reagent. This is common for mineral oil applications, for example. J-Pac can address this issue through its degassing and vacuum sealing process.

Do you require refrigerated storage?

Keeping reagents cool for the duration of their lifecycle introduces added storage, logistics and manufacturing concerns that drive up production costs.

Consider the lifecycle of a reagent formula:

  • It is blended in a manufacturing facility under refrigerated conditions
  • It must be kept in cold storage prior to shipping
  • It can only be shipped via refrigerated truck or air freight and not in bulk shipping containers
  • It must remain in cold storage prior to manufacturing
  • Heat sealing during blister manufacturing introduces the risk that reagents reach too high a temperature
  • Finished testing cartridges must stay in refrigerated storage until use

Developers must be fully aware of the added cost and difficulties that come with temperature-sensitive application.

What is your scale-up plan over time?

The way you plan to scale up production is an important manufacturing and cost consideration.

Will you only produce at low volumes of around tens of thousands of units to a few hundred thousand units per year? Will you scale up to mid-volume production of several hundred thousand units to a couple million annually? Will you achieve high-volume production of tens of millions of units or more?

Each volume differs in the capital required to secure supplies and equipment and the cost to manufacture each unit. Obviously, costs decrease as scale increases. Developers should be prepared for lower returns—or even losses—in early production stages. Gains at higher volumes will erase early losses.

Can your design leverage the J-Pac blister platform?

Because J-Pac Medical was among the first to develop reagent blister manufacturing technology, we’ve created a proven platform that’s brought tens of millions of reagent blisters to market.

Adopting a proven platform comes with three key advantages:

First, this eliminates most of the blister design and manufacturing process legwork, speeding the development timeline significantly.

Second, an existing platform means material procurement channels are already established. In addition to further speeding your program, this results in lower material costs.

Finally, a proven platform means our manufacturing infrastructure is already geared up to produce at any volume you require; the equipment and labor force responsible for manufacturing is already in place. Again, this reduces overall cost.

To learn whether the J-Pac diagnostic reagent blister platform will work for your product, order a sample kit now. We might be about to lift a great weight off your shoulders.

Get more guidance on reagent blister manufacturing

J-Pac Medical has been on the forefront of microfluidic testing products and processes ever since the technology began to emerge over two decades ago. For more detailed product planning information, read our reagent blister design development white paper.

And, our engineers would love to hear more about how your product planning is coming so far. To ask questions or brainstorm ideas with one of them, reach out here.