By Melissa Fassbender, Associate Editor, PD&D
More than 235 million people worldwide suffer from asthma, according to the World Health Organization. So, when Italian pharmaceutical company,
ChiesiFarmaceutici, developed a new medicine in the form of a
powder, they turned to product development firm Cambridge
Consultants for a revolutionary inhaler design. The result of the
collaboration is the NEXThaler, a dry powder inhaler with an innovative design.
“Our brief from ChiesiFarmaceutici was to design an intuitive and
simple to use inhaler. We started with
a blank sheet of paper, and worked
our way through a number of dif-
ferent concepts,” explains Matthew
Allen, drug delivery program director at
Cambridge developed many
ways to achieve the
the primary focus
was to keep the
device simple and
easy to use.
“There were many
stages of development,” explains Allen.
The first stages includ-
ed conversations and sketches on whiteboards. Next, the team
began molding foam prototypes for handling. "We used engineer-
ing foam that was hand formed with a scalpel, that way we could
have a physical model to demonstrate size and shape of different
Using such prototyping tools allowed the designers to iterate
models quickly, and to get physical designs into the hands of users
for feedback. “As the concepts became more refined, we held early
stage user studies using 'looks like' prototypes manufactured with
stereolithography,” he adds. The proof of principle models were
used to further test the functionality of the device.
The NEXThaler was then modeled using both ProENGINEER and
Solid Works CAD packages. ANSYS FLUENT Computational Fluid
Dynamics (CFD) modeling software was used to design the aerosolization engine and air paths, and some finite element analysis
(FEA) modules packaged with 3D CAD, were carried out early on
to assist in designing the flexible features of the device. Finally,
Cambridge Consultants used a Bespoke Software tool for statistical
tolerance analysis. "These manufacturing techniques offer efficiency and fast turn around, which is useful during the development
phase of a device,” says Allen.
The device comprises functional groups of components coupled
together. The dosing mechanisms meter the drug from a reservoir,
and the counting mechanisms, which include the breath actuated
mechanism, activates the dosing group under a certain air flow,
allowing the dose to be taken.
In the final stages of the design process, the team built two cavity injection mold tools and used the parts to verify the design. “In
order to scale up the design to commercial level, further tools were
built, including soft tools, to both explore the design space, investigate potential design improvements for scale up, and to build
devices for development of the assembly process,” Allen adds.
Designing for simplicity, using the NEXThaler is easy. "All you
have to do is open, inhale, and then close it; there is nothing else
the patient has to do.” There is no active aerosolisation engine;
instead, the aerosolization is produced by the patient breathing—a
primary design challenge, according to Allen.
A reservoir inside of the device houses the medicine, and each
time a patient opens the cover and breathes through it, the right
dose of the powder formulation is dispensed. To sense the user’s
breath, the device is equipped with a small vane that moves when
the patient breathes, triggering the dispensing mechanisms.