Design verification testing for an inhaler

Challenge

Our client asked us to perform comprehensive Design Verification Testing (DVT), under cGxP controls, for a breath-actuated pressurized metered dose inhaler (pMDI). We focused on the performance and reliability of the product’s mechanical function, in line with the latest standards and regulations.

Approach

We planned and completed a comprehensive DVT program to test the performance of hundreds of pMDI samples through their 120-shot use life. For every shot, our testing captured data for eight key functional requirements. To achieve this high fidelity testing in the most efficient way possible, we developed and validated over 30 bespoke test methods and commissioned and qualified two sophisticated semi-automated test instruments which were used in-house throughout the program.

Outcome

We successfully tested and analyzed data from more than 120,000 actuations from over 1,000 inhaler samples. The evidence we gathered and reported for this DVT program supported the launch of the product in Europe in September 2018 as an asthma treatment for adults and adolescents.

Sector
Drug delivery

Services
Device testing
Mechanical engineering
Electronics engineering
Quality assurance

A testing program within full cGxP controls

Our client partnered with Team for the industrialization, scale-up and Design Verification Testing (DVT) of their novel, breath-actuated pMDI for treatment of asthma. The product submission had already been filed which meant that the scope for change was extremely constrained and the project team had to work within full cGxP controls throughout.

We completed detailed tolerance analysis and built mathematical models to understand the design parameters of the device. Alongside this, we also carried out testing programs to de-risk the design and optimize performance prior to DVT.

person looking at an inhaler in a test rig

A unique drug delivery testing challenge

The inhaler’s design complexity presented a testing challenge because up to eight functions needed to be measured for each actuation, throughout each device’s 120 shot use life.

To meet statistical sampling requirements and the requirements of ISO 20072:2013, we needed to test and gather data from over 1,000 pMDI samples ‘through life’. We designed, commissioned and validated bespoke semi-automated test instruments which became the ‘work horses’ of DVT, outputting comprehensive data for detailed analysis.

All testing work was performed in Team’s laboratory facilities which could maintain the closely controlled ISO 20072 ‘standard atmosphere’ test environment needed for inhaler DVTs.

The amount of information we needed to gather and analyze during this DVT program was daunting and would not have been feasible with traditional, manual testing. Developing and commissioning test equipment suitable for high throughput testing meant we were able to gather large volumes of detailed information. This, coupled with the insights from our team of technicians and analysts, allowed us to capture comprehensive information about the inhaler’s key inhaler functions quickly and with a high level of confidence.
Jamie Greenwood, Senior Scientist, Team

Environment, health and safety matters during device testing

The potent nature of the drug product, coupled with the need to fire numerous doses in testing, meant that we had to implement containment measures to avoid exposure. To achieve this, we commissioned bespoke containment facilities and implemented ongoing environmental monitoring to ensure the health and wellbeing of our staff throughout testing.

A multidisciplinary design verification testing program

The analysts’ familiarity with the device characteristics brought the more subjective observations like the sounds and the feel of the device to the front. This helped the design and engineering team target specific solutions to optimize manufacturing parameters at the component level, thus ensuring capable molding and assembly processes leading to a robust product.

The analysts’ familiarity with the device characteristics brought the more subjective observations like the sounds and the feel of the device to the front. This helped the design and engineering team target specific solutions to optimize manufacturing parameters at the component level, thus ensuring capable molding and assembly processes leading to a robust product.
Chris Hurlstone, Director of Drug Delivery, Team

Automated dose counter assessment

The product includes an integrated, mechanical dose counter which indicates the number of puffs remaining. This information needs to be presented clearly and correctly to end users. This meant the dose counter was a performance-critical function and needed to be comprehensively tested to ensure it was accurate and reliable.

The challenge was to develop a test method which allowed for the dose counter to be assessed in an objective way while complying with current data integrity requirements. To achieve this, the dose counter display had to be captured by pictography after every actuation. To support the need for high throughput, we automated this process and the result was a validated methodology, built on our detailed understanding of the inhaler functions, which produced comprehensive and robust data to support detailed assessments of the dose counter’s performance in DVT.