Speaker's Highlight

• Don Sin University of British Columbia, St. Paul Hospital (Canada)
  Kenneth R. Chapman Toronto General Hospital Research Institute (Canada)
• Parameswaran Nair McMaster University (Canada)
  Carolyn Calfee UCSF (U.S.A.)
• Gregory P. Downey University of Colorado School of Medicine (U.S.A.)
  David A. Schwartz University of Colorado School of Medicine (U.S.A.)
• Neil Schluger Tuberculosis Control Branch, California Department of Public Health (U.S.A.)
  Nick Kim Critical Care & Sleep Medicine, University of California San Diego (U.S.A.)
• Nicola Hananiah Baylor College of Medicine (U.S.A.)
  Jae-Joon Yim Seoul National University College of Medicine (Republic of Korea)
• Koichiro Asano Tokai University School of Medicine (Japan)
  Diahn-Warng Perng Taipei Veterans General Hospital (Taiwan)
• Konstantinos Kostikas University of Ioannina (Greece)
  Karin Klooster University Medical Center Groningen (Kingdom of the Netherlands)

• Novel inhaler devices for improved drug deposition

  Inhaled medicines work best when the right dose reaches the right part of the respiratory tract. That sounds straightforward, yet the journey from actuator to lung is affected by particle size, inspiratory flow, airway anatomy and the patient’s technique. A substantial proportion of each dose can remain in the mouth or throat instead of reaching the bronchi and smaller airways.

  Novel inhaler devices are designed to address these gaps. Advances include breath-actuated inhalers, soft-mist inhalers, digitally enabled systems and dry powder inhalers with improved resistance profiles. Their value lies in making aerosol delivery more consistent, especially for people who struggle to coordinate pressing and breathing.

  This is highly relevant to respiratory medicine in Australia, where clinicians manage asthma, chronic obstructive pulmonary disease, bronchiectasis and other conditions across major cities, regional centres and remote communities. A “puffer” may be familiar language in the consulting room, but familiarity does not guarantee correct use.

  For a congress audience connected with APSR and KATRD, device innovation also raises practical questions. Better deposition must be balanced with affordability, environmental impact, medicine availability through the Pharmaceutical Benefits Scheme and the realities of care in places such as Perth, Darwin, rural New South Wales and the Australian Capital Territory.

  Why deposition matters in respiratory care

  Drug deposition describes where inhaled particles settle after entering the airways. Larger particles tend to impact in the mouth and upper airway, while smaller particles can travel further into the bronchial tree. The ideal distribution depends on the medicine and disease target: some treatments need central airway delivery, while others benefit from reaching peripheral lung regions.

  Poor deposition can reduce clinical response and increase local adverse effects such as oral candidiasis or dysphonia with inhaled corticosteroids. It may also lead to unnecessary escalation when the real problem is that the medicine is not being delivered effectively.

  A patient may have an appropriate prescription but still receive an inconsistent dose because of poor hand-breath coordination, a weak inspiratory effort or an inadequate breath hold. Device selection is therefore part of treatment design rather than a minor packaging decision.

  Limitations of conventional inhalers

  Pressurised metered-dose inhalers release a suspension or solution propelled by a liquefied gas. They are compact, widely available and useful for patients who cannot generate a strong inhalation. Their main limitation is the need to actuate the device while beginning a slow, deep breath.

  Spacers reduce oropharyngeal deposition and make coordination easier, particularly for children and people experiencing an acute flare. However, spacers are bulky, can be misplaced and require cleaning. In Australian households, school bags and hot cars can create additional practical problems for storage and regular use.

  Dry powder inhalers remove the need for propellant coordination, but they depend on the patient’s inspiratory flow. A person with severe airflow obstruction, advanced COPD or marked fatigue may not generate enough energy to disperse the powder properly. Device resistance and formulation therefore need to match the patient’s capacity.

  Breath-actuated and soft-mist systems

  Breath-actuated inhalers release medication when the patient begins to inhale. This reduces the timing burden associated with a pressurised inhaler and can improve consistency for people who repeatedly press too early or too late. The device still requires an adequate inspiratory manoeuvre and careful instruction.

  Soft-mist inhalers create a slow-moving aerosol cloud with a longer plume duration than many pressurised devices. The lower velocity can reduce impaction in the throat and provide more time for the patient to inhale. For selected patients, this may improve lung deposition without relying on a high peak inspiratory flow.

  The clinical advantage is not automatic. Loading, priming and dose preparation can involve several steps, and some systems are less intuitive for people with arthritis, visual impairment or cognitive difficulties. Demonstration with a placebo device remains essential.

  Advances in dry powder delivery

  Newer dry powder inhalers use engineered carrier particles, capsule-based systems or multidose reservoirs to improve powder deaggregation. When the patient inhales, the formulation separates into respirable particles that can travel deeper into the lungs. Device resistance is calibrated to produce adequate turbulence without demanding excessive effort.

  Some platforms provide feedback when the patient has inhaled correctly. Audible, visual or tactile signals may help patients recognise a complete dose, while dose counters reduce uncertainty about remaining medication. These features are particularly useful when symptoms fluctuate and patients use preventers and relievers differently.

  Digital inhalers can record actuation, inhalation timing and, in some models, inspiratory flow. Such information may support adherence discussions and remote review. Yet data should complement clinical assessment, not replace observation of technique or create a sense that every patient needs a connected device.

  Patient-centred device selection

  The best inhaler is the one a patient can use correctly and consistently. Clinicians should assess cognition, dexterity, vision, inspiratory flow, disease severity and the number of devices already prescribed. Repeatedly switching between different mechanisms can create confusion, especially when a reliever and preventer look similar but operate differently.

  Education should involve teach-back: the patient demonstrates the complete sequence while the clinician checks preparation, inhalation, breath hold and mouth rinsing where relevant. Technique needs review at follow-up, after hospitalisation and whenever control deteriorates unexpectedly.

  Australia’s geography makes flexibility important. A respiratory nurse in Cairns may need to consider heat, humidity and access to follow-up, while a patient in remote Western Australia may depend on a smaller number of local services. Devices should be practical for the patient’s daily routine, not selected solely because they have the newest features.

  Environmental and health-system considerations

  Propellants used in some pressurised inhalers have a climate impact, and manufacturers are developing lower-global-warming alternatives. Dry powder and soft-mist options may reduce reliance on propellants, although their environmental profile also includes manufacturing, packaging, transport and disposal.

  The Australian market is shaped by regulatory approval through the Therapeutic Goods Administration and reimbursement decisions under the PBS. A technically impressive inhaler has limited public-health value if it is difficult to obtain, expensive for the patient or unavailable in the strength required.

  Clinicians also need to consider medicine continuity. A device that improves deposition in laboratory testing may be unsuitable if pharmacies in regional Queensland or Tasmania cannot reliably stock it. Formularies, substitution practices and supply interruptions can influence whether a theoretical advantage becomes a real clinical benefit.

  Comparing delivery platforms

  Evidence should combine laboratory measures, pharmacokinetics, patient usability and clinical outcomes. Fine-particle fraction and lung deposition imaging can show how a device behaves, but these findings need to be interpreted alongside exacerbations, symptom control, adherence and adverse effects.

  Different technologies solve different problems. A soft-mist inhaler may help someone with poor coordination, whereas a high-resistance dry powder device may be unsuitable for a patient with very low inspiratory flow. A pressurised inhaler with a spacer can remain an excellent option when the patient is trained and the equipment is available.

  Device approach	Main deposition advantage	Key limitation	Suitable clinical consideration
  Pressurised metered-dose inhaler	Reliable aerosol output and broad medicine availability	Requires coordination; higher throat deposition without a spacer	Pair with a spacer when technique or coordination is difficult
  Breath-actuated inhaler	Releases dose during inhalation	Still requires correct inspiratory effort	Useful when actuation timing is the main barrier
  Soft-mist inhaler	Slow plume may improve inhalation time and reduce impaction	Priming and preparation can be more complex	Consider for patients who struggle with fast aerosol delivery
  Dry powder inhaler	Breath-driven delivery avoids propellant and actuation timing	Requires adequate inspiratory flow and correct loading	Match resistance and formulation to lung function
  Digitally enabled inhaler	Can provide adherence and technique-related feedback	Cost, privacy and technology burden	Use selectively where monitoring supports care

  The central principle is that improved drug deposition should translate into better treatment, not simply better engineering measurements. Device choice, inhaler training and access to the prescribed medicine must work together. What readers should remember is simple: the most advanced inhaler is valuable only when its design matches the patient, the medicine reaches the intended lung region and the treatment can be used reliably in everyday Australian life.

  Richard Russell Nuffield Department of Clinical Medicine, University of Oxford (United Kingdom)
• Mona Bafadhel King’s College London (United Kingdom)
  David Jackson Guy’s and St Thomas’ Hospital, King’s College London (United Kingdom)
• James Chalmers University of Dundee (United Kingdom)
  David Price University of Aberdeen (United Kingdom)