Pharmapack 2026: Solving the Intradermal Delivery Puzzle

To efficiently and accurately target the immune-rich dermal layer, drug delivery devices must overcome user-dependent variables, explains Michele Guasti from Terumo Medical Care Solutions.

The next generation of potent biologics and vaccines require a delivery route that maximizes immunogenicity, often leading researchers straight to the dermis. However, the traditional Mantoux technique is notoriously difficult to standardize. In an exclusive interview with The Pharma Navigator, ahead of Pharmapack 2026, Michele Guasti, Global Product Manager within the Pharmaceutical Solutions Division of Terumo Medical Care Solutions, discusses the critical geometric parameters — from needle bevel geometry to perpendicular insertion — that allow modern devices to achieve consistent dermal deposition.

Focusing on Eliminating Variables

TPN: Intradermal delivery is often used for highly potent vaccines or biologics, how does the Human Factors Engineering strategy for a specialized device differ from a standard subcutaneous autoinjector, particularly in ensuring correct engagement to achieve the target layer?

Guasti: A Human Factors Engineering strategy for an intradermal‑specific device must solve a fundamentally different problem than a standard subcutaneous autoinjector. Subcutaneous systems are designed with a wide margin for anatomical variability — if the needle reaches the fatty layer beneath the skin, the device has succeeded. Intradermal delivery, however, requires the needle to stop within a very narrow band only a couple of millimeters below the surface. Missing that layer by even a small amount can compromise the intended immune response or therapeutic effect.

Because of this, the strategy for an intradermal device focuses on eliminating user‑dependent variables such as angle and needle penetration depth. Traditional intradermal techniques require the practitioner to manage these factors manually, and outcomes vary significantly with skill and experience. A specialized device therefore must be engineered so that correct placement is achieved through its physical design rather than user technique.

This is why intradermal‑specific systems incorporate features such as a fixed, extremely short needle, a controlled insertion angle, and physical stops that prevent the device from penetrating too deeply. These elements ensure that when the user presses the device against the skin, the needle naturally seats itself within the dermis. Human factors validation for such a device focuses on confirming that it can consistently achieve correct dermal engagement without errors that would compromise safety or delivery accuracy.

A Specific Set of Geometric Constraints

TPN: What are the key geometric design parameters that are most critical to guaranteeing consistent deposition specifically within the dermal layer versus the subcutaneous tissue?

Guasti: To consistently deliver a formulation into the dermis rather than the subcutaneous layer, the device must be engineered around a very specific set of geometric constraints. Unlike subcutaneous delivery — where the target tissue is broad — the dermis is thin, shallow, and requires millimeter‑level precision. That means the geometry of the needle and the physical interface of the device become the primary determinants of success.

Needle Length: The most critical parameter is the exposed needle length. The dermis is only a couple of millimeters thick, so the needle must be short enough that, even when fully inserted, it cannot pass through into the subcutaneous fat. A fixed, shallow penetration length ensures that the tip remains within the dermal layer regardless of user force or skin variability.

Needle Gauge and Bevel Geometry: A very fine gauge and a short bevel help the needle seat itself within the dermis rather than going deeper. A small outer diameter reduces insertion force and tissue displacement, while a short bevel minimizes the risk of the tip extending beyond the intended layer. Together, these features help the needle remain anchored in the dermis during injection.

Perpendicular Insertion Orientation: The device’s geometry must enforce a perpendicular angle relative to the skin. This eliminates the variability seen in traditional angled intradermal techniques and ensures that the needle enters the skin at a predictable depth. A perpendicular approach also reduces the chance of sliding under the epidermis or penetrating too deeply.

In essence, intradermal‑specific devices rely on a tightly controlled combination of needle length, gauge, bevel geometry, and insertion angle. These parameters work together to ensure that correct dermal deposition is achieved by design, not by user technique.

A Great Opportunity

TPN: Finally, what are you most looking forward to at Pharmapack 2026 and, if you are exhibiting, where can visitors find you during the show?

Guasti: I’m looking forward to Pharmapack 2026 as it’s one of the rare moments in the year where the global drug‑delivery and packaging community comes together, and the level of innovation on display is always inspiring.

As exhibitors, we’re especially excited to present our primary container solutions alongside our full portfolio of injection and infusion systems. It’s a great opportunity to exchange with international partners, explore new collaborations, and discuss how smarter, safer delivery technologies can shape the future of patient care.

Terumo Pharmaceutical Solutions Division will be exhibiting at booth 4C21. See you there!

About the Interviewee

Michele Guasti is the Global Product Manager within the Pharmaceutical Solutions Division of Terumo Medical Care Solutions. He holds a Master’s degree in Mechanical Engineering from the University of Brescia in Italy, and has spent more than a decade working in primary packaging for the pharmaceutical industry.

Over the past five years, Michele’s focus has expanded into fill/finish processes for injectable drugs and the technologies that support them. Throughout his career, he has been deeply involved in building strong partnerships across the industry and helping pharmaceutical companies address their daily technical and operational challenges.

Before joining Terumo, Michele worked in strategic product management at Stevanato Group, which further strengthened his expertise in drug‑delivery and container solutions. In Michele’s current role, he is responsible for guiding the development and strategy of Terumo’s CDMO activities, ensuring they meet the evolving needs of customers and ultimately contribute to safer, more reliable therapies for patients worldwide.

Image Credit: © Christian Horz - stock.adobe.com