Revolutionising respiratory health: inhalation drug product testing
It’s estimated that around 545 million individuals worldwide live with chronic respiratory conditions. Given its prevalence, inhalation therapeutics are an integral focus within the R&D realm to evolve treatments.
With inhalation pharmaceutical developments comes a comprehensive range of testing methods and tools, used to validate and qualify each new product as safe and viable and provide critical insights into formulation and design.
Modern medicine transforms inhalation therapeutics
Innovation in inhalation products is driven by the need to manage life-threatening respiratory diseases. These therapeutics are widely executed within modern healthcare to manage the treatment of chronic respiratory conditions such as asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis.
Such conditions are a collective and global burden to our health, as they require continuous management to ensure a patient’s quality of life remains sufficient.
Inhalation therapies have a documented history dating back to ancient times, with the official development of inhalation chambers recorded during the 17th and 18th century. This laid the foundations for the commercialisation of steam-driven and powder inhalers. These then led to the most revolutionary step of inhalation therapeutic development; the first Metered-dose inhaler (MDI) devised in the 1950s.
Fast forward to today where a vast range of devices are available, from MDIs, Dry Powder Inhalers (DPIs), Nebulisers, Breath-Actuated Inhalers and Soft Mist Inhalers (SMIs) to name a few. Continuing the pursuit of identifying pharmaceuticals with ultimate convenience, efficiency and effectiveness, modern inhalation therapies continue to evolve, from advanced inhaler technology to targeted drug delivery, novel medications and new drug formulations.
Inhalation drug product testing
Innovative inhalation approaches are being targeted by researchers as they present an opportunity to deliver new medications. With this comes the regulatory range of testing measures that assess all aspects of inhalation products.
From metered dose inhalers (MDIs) to aerosol solutions for vaccines, insulin, gene therapies, and other innovative treatments, inhalation drug product testing is a vital stage in revolutionising modern medicine. It holds the potential to shape the way we approach therapeutic administration moving forward!
Vital parameters in inhalation therapeutic assessment
Standardised inhalation drug product testing methods ensure reliable assessment of chemical formulations and product designs, thus determining the overall quality, consistency and performance verification of new inhalation devices.
These testing methods investigate important factors, including particle size, fine particle fraction (FPF), disposition pattern, lung deposition efficiency, as well as dissolution, stability, and microbiological parameters. Factors such as particle size, formulation changes and device modifications can all impact drug delivery, and so with every modification to the drug compound or device, testing is employed again to validate its efficacy.
These testing methods require specialised inhalation equipment such as Next Generation Impactors (NGI), Andersen Cascade Impactors (ACI), Dosage Unit Sampling Apparatus (DUSA) and Breathing Simulators. We explore these in detail below:
Andersen Cascade Impactors (ACIs)
The original impactor, ACIs are widely used multistage impactors employed to separate particles based on their aerodynamic size. Researchers use this method to analyse particle size distributions and assess drug inhalation performance.
This method employs a series of plates and impactor stages to create high-velocity jets of air. These transport the particles through the impactor in a cascading pattern, with all particles separated out based on their aerodynamic sizes.
Next Generation Impactors (NGIs)
Next Generation Impactors (NGIs) are an evolution of the ACI, designed specifically for pharmaceutical testing and deployed as a higher throughput and less labour-intensive technique.
Used with metered-dose and dry-powder inhalers, nebulisers and nasal sprays, NGIs are often standard practice for assessing valuable parameters for drug efficiency and effective drug delivery.
The process involves dividing particles by their aerodynamic properties, achieved through inertial impaction. As the aerosol sample passes through the impactor, inertial forces cause particles of varying sizes to change direction.
This is often partnered with microscopy, or laser diffraction to assess particle characteristics such as size and particle morphology.
As well as qualifying the effectiveness of the therapy, NGIs play an important role in evaluating formulation changes or design modifications to achieve optimal drug delivery formulations.
Dosage Unit Sampling Apparatus
Dosage unit sampling Apparatus (DUSA) involve specialised equipment often used to collect representative samples for the evaluation of dosage quality and uniformity. This provides valuable insight into its overall consistency and performance.
The DUSA test involves sample collection via an adaptor, specifically designed to collect samples from inhalation and nasal spray devices. The sample is then analysed to determine the API content, using techniques such as HPLC or Spectroscopy.
Breathing simulators
Breathing simulators are highly efficient equipment that provides standardised and controlled testing conditions for drug evaluation. This process simulates human breathing patterns and characteristics by mimicking inhalation and exhalation patterns.
Breathing simulators provide a range of respiratory parameters to be measured and analysed, including tidal volume, breathing frequency, inspiratory flow rate and breath-hold times.
The simulators replicate breathing profiles by adjusting these parameters, simulating breathing patterns of people of all ages as well as those with specific respiratory conditions.
In a controlled and reproducible environment, these simulators provide valuable assessment into drug delivery efficiency, allowing analysts to assess drug performance during formulation development.
Safeguard your inhalation innovation with HMR
To facilitate manufacturers on their drug development journey, many vital tools are used to assess drug delivery efficiency, optimise formulation development, and comply with regulatory requirements.
The identification and evaluation of valuable parameters for inhaled drug effectiveness require thorough assessment, which can be tested with ease with HMR.
Our full range of inhalation drug product testing equipment includes multi-stage impactors, dosage unit sampling devices and breathing simulators. Partnered with our team of analytical scientists with extensive inhalation expertise, it allows for an effortless drug evaluation process, including strict quality assurance processes to ensure accurate and reliable results.
Looking to test your metered dose inhalers (MDIs), dry powder inhalers (DPIs), aqueous mist inhalers, nebuliser solutions, suspensions, or aerosols?
HMR is here to help you on your journey to the shelf. Partner with HMR today.