Beyond the Barrel: A Dual-Cartridge Improvement to Traditional Dual-Chamber Devices

As featured in On Drug Delivery

Dr Brent Buchine of Windgap Medical explores how the company’s devices transform dual-chamber systems with a modular, scalable and remarkably simple approach to reconstitution and complex drug delivery.

HAVE DUAL-CHAMBER DEVICES HAD THEIR DAY?

Monoclonal antibodies. Depot suspensions. Long-acting biologics. As R&D pipelines swell with increasingly complex injectable therapies, so does the need for delivery systems that can administer them safely, simply and swiftly at the point of care.

However, while drug formulations have advanced, many of the delivery systems supporting them have not. Once considered a breakthrough, traditional dual-chamber cartridges (DCCs) – glass barrels separated by stoppers with internal bypasses – are now becoming a bottleneck. Their rigid formats, intricate filling and assembly requirements and limited capacity can slow down development, drive up costs and frustrate end-users.

At the same time, dual-chamber pens and autoinjector platforms face their own constraints, often requiring manual shaking, awkward orientations and complicated steps that introduce new risks for patients and providers alike.

The industry is at a turning point. The delivery systems that once reduced complexity are now introducing it. For biopharma teams advancing the next generation of inj

ectables, this shift demands more than a retrofit. It calls for a fundamental reimagining of delivery architecture, designed to meet modern development demands and patient realities, side by side.

THE CASE FOR EVOLVING THE DUAL-CHAMBER STANDARD

Traditional DCCs were designed to solve a specific problem: keeping a drug and diluent separate until the moment of injection. For many applications, they succeeded. But as drug formulations have grown more complex, the limitations of this architecture have become harder to engineer around.

Formulations Face Physical Limitations: With drug and diluent housed end to end, teams must work within fixed volumes, constrained geometries and rigid process sequences – all of which can complicate formulation development for viscous biologics, lyophilised compounds or suspensions.

Manufacturing Requires a Multistep Fill Process: Where each chamber must be filled, lyophilised, stoppered and inspected independently, often on specialised equipment with limited global capacity.

Supply Chain Constraints Introduce Added Vulnerability: Only a small number of vendors supply DCCs, creating concentration risk at a critical point in the manufacturing process.

The Device Itself: To mix and deliver the drug, DCC-based devices must break internal stoppers or open internal bypasses. This adds mechanical complexity to the device, increases the potential for particulate generation and limits the design flexibility available to drug delivery engineers.

While DCCs have played a significant role in extending the application of injectables, the question for biopharma teams is no longer whether dual-chamber capability is needed, but whether the existing architecture is still the right way to deliver it.

THE PARALLEL DUAL-CARTRIDGE ADVANTAGE

Windgap Medical’s portfolio of devices takes a fundamentally different approach: rather than combining drug and diluent in a single glass barrel, the two components are housed in separate cartridges and brought together as part of an integrated injection system.

Independent Fill and Lyophilisation: Each cartridge is filled and lyophilised separately using standard equipment and processes, reducing manufacturing complexity and opening access to a broader range of contract manufacturers.

Flexible Volumes and Geometries: Without the dimensional constraints of a shared barrel, formulators have greater freedom to optimise drug and diluent volumes independently – a significant advantage for high-concentration biologics or lyophilised compounds that require specific reconstitution conditions.

Reduced Supply Chain Risk: Standard, commercially available glass cartridges replace proprietary DCCs, distributing sourcing across a wider supplier base and reducing concentration risk.

Simplified Device Mechanics: Instead of breaking internal stoppers or opening bypasses, the Windgap platform uses a precise plunger sequence to mix and deliver the drug – reducing particulate risk and simplifying the device architecture.

The result is a system that delivers dual-chamber functionality without dual-chamber constraints.

ARCHITECTURE MEETS APPLICATION

The Windgap portfolio currently includes four platform devices, each designed to address a specific segment of the dual-chamber delivery landscape.

DualFlo Autoinjector: A fixed-dose autoinjector for subcutaneous delivery of reconstituted biologics. DualFlo uses a parallel dual-cartridge system to keep drug and diluent separate until actuation, enabling simple, one-step reconstitution and injection without the mechanical constraints of traditional DCCs.

OneMix Autoinjector: A platform for subcutaneous delivery of viscous or lyophilised drugs that require more controlled reconstitution. OneMix incorporates a mixing mechanism that ensures complete and consistent reconstitution before injection, supporting drugs with more demanding mixing requirements.

MultiMix Autoinjector: A platform for combination drug products that require the mixing of more than two components. MultiMix extends the dual-cartridge architecture to support more complex formulations while maintaining the simplicity and usability standards of the Windgap platform.

DuraMix Reusable Autoinjector: A reusable platform for drug products requiring long-term administration. DuraMix is designed to reduce device waste while maintaining the precision and reliability needed for chronic or depot therapy regimens.

THE SMARTER PATH FROM DEVELOPMENT TO DELIVERY

Windgap’s dual-cartridge platform is not just a mechanical improvement – it is a lifecycle advantage, designed to reduce development and manufacturing friction from formulation to final dose.

Early Development – Flexibility and Forward Progress: Standard cartridge formats allow formulation teams to iterate quickly and run preclinical studies without the need to lock complex packaging. Reconstitution steps can be validated early, accelerating regulatory filings and the path to first-in-human trials.

Manufacturing – Streamlined and Synchronised: As drug and diluent are filled separately, teams can work across an established, trusted and validated supply base – easing co-ordination with CDMOs and minimising delays.

Commercialisation – One Format, Many Front Doors: Having a common dual-cartridge platform makes it easier to launch device variants for multiple indications, dosing regimens and patient populations – without starting from scratch. This reduces the time to market, cost of goods, complexity and overall risk.

Patient and Provider Use – Simplicity that Scales: Most importantly, these devices are designed with the end-user in mind. Both patients and healthcare providers benefit from fewer steps, shorter preparation times and less opportunity for error. This leads to lower risk and improved outcomes, whether they’re at a clinic, a kitchen table, or anywhere in between.

Few platforms deliver measurable benefits across development, manufacturing and user experience. Windgap’s does, by design.

CONTAINING COMPLEXITY: SOLVING THE NEED FOR MODULAR, SCALABLE AND SIMPLE

Modern injectable therapies are more viscous, more sensitive and harder to deliver than ever before – and the pressure to mix and administer them safely at the point of care is only growing.

Conventional thinking says rising complexity demands more complex devices. In fact, the more challenging the formulation, the more critical it becomes to have a system that simplifies delivery – creating new opportunities for formulation teams, patients and the industry as a whole.

The industry has long sought a platform that does more than deliver drugs. By rethinking the architecture at the core, Windgap’s platforms show how a single innovation can streamline formulation, simplify manufacturing, improve sustainability and elevate the patient experience.

By building on the trusted principles of dual-chamber delivery, Windgap’s platform evolves a familiar foundation into a modern solution, one designed to meet today’s complexity and tomorrow’s breakthroughs with greater ease, flexibility and scalability.

Dr Brent Buchine is the Co-founder and Chief Business Officer of Windgap Medical.