Using Prototypes to Accelerate Autoinjector Innovation

Sally Maclachlan November 11, 2025

The demand for reliable, user-friendly autoinjectors continues to grow. These devices must ensure safe, consistent performance for users, including those with limited dexterity. A leading pharmaceutical client approached Sanner to help develop a critical mechanism within their next-generation autoinjector that safely and reliably removes the syringe’s rigid needle shield (RNS) just before use.

The challenge

The client’s autoinjector design required a scalable precision-engineered component to facilitate effective and safe function. This part needed to:

  • Function reliably across multiple device variants, use scenarios and user abilities
  • Be manufacturable at scale without compromising accuracy or performance
  • Integrate seamlessly with the existing design and assembly constraints of the autoinjector

The complexity lay in achieving repeatable mechanical performance within a confined and already defined space, achieving tight tolerances in production, and ensuring the device cap could still be easily removed by users.

Our approach

Sanner applied a combination of engineering expertise, rapid prototyping, and industry collaboration to accelerate the development of this critical component.

  1. Understanding Functional Requirements
    Our team began by mapping the exact sequence of mechanical actions during device operation – from cap removal to injection initiation – identifying where the component played a key functional role.
  2. Leveraging Industry Expertise
    By engaging trusted industry contacts in medical device manufacturing, we were able to identify the most appropriate materials, forming processes, and tolerance control methods early in development.
  3. Rapid Prototyping and Iteration
    We developed bespoke prototyping techniques that allowed for quick iteration cycles. Each prototype was evaluated for reliability, manufacturability, and ease of operation, leading to incremental refinements and performance improvements.
  4. User-Centric Testing
    Prototypes were assessed with the end user in mind that even individuals with limited dexterity could operate the mechanism comfortably and confidently.

The outcome

We were able to deliver a robust and manufacturable design that met all functional and regulatory requirements. The resulting mechanism consistently removed the RNS with high reliability, supporting the overall usability and safety of the device.

Sanner’s collaborative and technical approach enabled the client to move forward confidently into detailed design and verification stages significantly reducing both development time and technical risk.