According to the World Health Organization, an estimated 262 million people around the world suffer from asthma, leading to almost half a million deaths. For sufferers of breathing issues such as asthma or Chronic Obstructive Pulmonary Disease (COPD), an inhalation device is required to make breathing easier. Inhaled medication can control asthma symptoms and allow people with asthma to lead a normal, active life. Unfortunately, access and affordability are barriers for many, especially the uninsured and those in lower income countries. Studies published in the Annals of American Thoracic Society and the Journal of Allergy and Clinical Immunology estimated the annual costs per person for asthma treatment between $1,800 and $4,900 for inhalers and medications prescriptions alone, including direct costs (e.g. medicine and visits to the doctor) -- and indirect costs (e.g. time off from work). A 2005 Health Costs Survey found that 44% of all people with asthma stopped taking their medicine or visiting the doctor in an effort to save money.
UK-based medical device company Coalesce Product Development seeks to address some of these issues. The company develops novel, innovative drug delivery devices including inhalers and injectors, for use in generic inhalation products that offer significantly better value than brand name alternatives that can cost over $380 per month.
Inhalers need to be usable by a wide cross-section of society, from adolescents to elderly patients with comorbidities. Therefore, the precise size, shape, and user interface of each new inhaler needs to be very carefully designed and tested. In order to achieve this, the Coalesce team has turned to using in-house 3D printers to prototype, test, and create various devices in a multitude of different shapes and sizes. To test each product in development, the company also develops its own 3D printed test rigs, jigs, and fixtures.
Coalesce first invested in SLA 3D printers in 2015. At that time, the team was still heavily relying on outsourcing for prototypes, waiting days at a time for their parts to arrive in the mail. Before long, the team had multiple 3D printers and had significantly reduced their reliance on outsourcing.
Coalesce used the 3D printers to develop and prototype the crucial architecture for several inhaler and auto injector devices. For example, for caseworks of its electronic Breath Profiling Device (BPD), the designers chose White Resin for its smooth finish and mechanical properties, which allowed them to drill and add brass inserts.
Vinnay said at the time that “stereolithography offers a good balance of feature resolution, surface finish, durability, choice of materials, and dimensional accuracy. Because we develop devices with moving parts, we needed an effective way to prototype small mechanisms in-house. We kept an eye on advances in 3D printing technology over the past few years, and we liked the Formlabs approach. When the Form 2 was released, we ordered one immediately, followed by a second just a few weeks later.”
Initially, the 3D printed prototypes were used to develop the BPD’s exterior architecture. When the design was stable, the printed parts were painted and taken to the Drug Delivery to the Lungs (DDL) conference, an annual gathering of pulmonary and nasal drug delivery specialists. The BPD prototypes looked so realistic that they were often mistaken for a final, end-use product.
Eventually, the same device prototypes were used in a pulmonary function clinical study. The results showed how much variation can occur between different uninstructed inhalation profiles.
Using third party vendors would have cost approximately 20 times more than the raw cost of printing the parts in-house. The caseworks of the BPD cost £11 to produce on the Form 2 compared to around £250 when outsourced. According to Vinnay, however, the real benefit is the time saved: the parts took only eight hours to print and could be finished and painted within a few days. The same process would take an external contractor a week or two.
After bringing most of their 3D printing in-house with the Form 2, and using the machines as workhorses for years, the team upgraded their fleet by purchasing three Form 3s.
With the Form 3, Coalesce was ready to move from purely aesthetics and looks-like prototypes, to actually integrating 3D printing into the development of their devices, including creating minute internal features. Due to the accuracy of Low-Force Stereolithography (LFS) 3D printing delivered by the Form 3, the team has been able to solve major problems facing inhaler development, notably analyzing fine particle distribution of the delivered dry powder formulations using analytical testing to ensure a smooth and accurate delivery of various drugs.
Vinnay put it succinctly, saying that the new 3D printers "allowed us to print fine features and delicate meshes, and to optimise the device during the design phase. We have the ability to model a part, change it on the fly, and have the physical part in a few hours. We can cut out the third-party supplier, and we get the parts more quickly. The Form 3s are absolutely essential to us. I can’t imagine not having them.”
Today, the team is running three Form 3s nonstop, five days per week, making them an inseparable part of the development process. Use cases for 3D printing have continued to expand, with the team now printing tooling to help test their devices. An example is printing different mouth pieces in BioMed Clear Resin, a biocompatible, skin safe material, for patient trials. 3D printing allows the team to skip the creation of expensive injection molded plastic parts.