June 14, 2021 | Jeff Trail

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5 Key Considerations When Designing Drug Delivery Devices


In the current highly competitive medical device marketplace, drug delivery devices are among the fastest growing segment. Drug delivery and fluid management devices are used across the medical device and biotechnology markets. These devices store, transfer, and process liquid media and include products such as pre-filled syringes, auto-injectors, infusion pumps, transdermal drug delivery, gels, process aids, and other liquid media solutions.

Many of these devices are launched as combination products and strictly regulated by the FDA via 21 CFR Part 4, which guarantees the drug is introduced to customers in a safe and viable way. This piece is focused on the primary considerations to keep in mind when designing drug delivery devices.


What Is a Combination Product?

The adoption of 21 CFR Part 4 came along with the term "combination product." A combination product refers to a medical device that comprises two or more different types of products, for example, a combination of a drug, device, and biological product. In essence, this means the device has to be co-developed alongside the drug or biological. Other considerations include reduced manufacturing cost, increased labor productivity and machine efficiency, improved product quality, increased system reliability, shorter lead times, and improved production rate. This has to be tuned to specific drug product features, primary container, and fill volume.



Key Considerations


Adaptive Manufacturing

An adaptive manufacturing strategy provides the flexibility needed to develop, produce and deliver demand-driven medical devices while leveraging existing resources. It focuses on the logistics of efficiently deploying finite resources to assemble, transport, sustain and distribute products while managing supply chain disruption effectively. Medical device manufacturers who prioritize an adaptive manufacturing process stand to gain from increased machine efficiency, improved product quality, reduced parts inventory, shorter lead times, and increased production rate.


Concurrent Engineering

When designing a combination drug delivery product, there is a need to keep in mind key aspects of concurrent engineering to ensure the delivery device will be developed alongside the drug product. Essentially, the choice of primary container components and specifications can have a massive impact on the entire device development, and performance should not be overlooked. In addition, the suitable container or applicator should guarantee that the drug product is protected and delivered seamlessly by the device.

During the design and development, one should also factor in their supply chain strategy and commercial interests. Selecting a primary container will also involve the following assessments and considerations:

  • The primary container material's impact on drug stability over the product's shelf life
  • The drug's interaction with the primary container
  • Compatibility of the primary container system with the selected device and manufacturing process
  • The container closure and sterilization process
  • The filling process as it relates to the behavior of drug
  • The product assembly steps


Packaging and Shipping

Additionally, it is worth noting that a significant percentage of challenges with combination products are packaging-related. During design, manufacturers should evaluate the device for packageability and shipping risks as part of their device evaluation and selection process. Prioritizing the packaging process early in the design stage helps identify defective device designs to avoid massive program risks when the devices had passed all other considerations.



Biocompatibility, and measures that guarantee patient/user safety, focus on the device's direct and indirect user interface elements that ensure it is safe for users to handle. The FDA takes biocompatibility considerations very seriously, and device manufacturers should carefully analyze their vendor's biocompatibility data to guarantee they meet the biocompatibility guidelines set in the 2016 FDA-issued guidance on ISO 10993.


Clinical Needs

As more combination products are increasingly being paired with digital solutions, the patient's clinical needs are one key area that should be considered during the design and development of a combination device. An ideal method should leverage digital solutions to ensure enhanced medication adherence and compliance to trial protocols and regimens. 



In this rapidly growing market segment, drug delivery device R&D is constantly innovating. As a result, device systems are becoming more user-friendly, less risky, and are available at decreasing cost. The main goal of a device designer is to develop a delivery system that guarantees high usability with more comfort and less pain for the user. The considerations discussed in this piece will help ensure a device's robustness, safety, and reliability.


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