Inhalation devices: from basic science to practical use, innovative vs generic products

A path forward in the development of new aerosol drug delivery devices for pediatrics

Inhaled medications are widely accepted as being the optimal route for treating pediatric respiratory diseases, a leading cause of hospitalization and death. Despite jet nebulizers being the preferred inhalation device for neonates and infants, current devices face performance issues with most of the drug never reaching the target lung location. Previous work has aimed to improve pulmonary drug deposition, yet nebulizer efficiency remains low. The development of an inhalant therapy that is efficacious and safe for pediatrics depends on a well-designed delivery system and formulation. To accomplish this, the field needs to rethink the current practice of basing pediatric treatments on adult studies. The rapidly evolving pediatric patient (i.e. neonates to eighteen) needs to be considered because they are different from adults with respect to airway anatomy, breathing patterns, and adherence. Previous research approaches to improve deposition efficiency have been limited due to the complexity of combining physics, which drives aerosol transport and deposition, and biology, especially within the area of pediatrics. To address these critical knowledge gaps, we need a better understanding of how patient age and disease state affect deposition of aerosolized drugs. The complexity of the multiscale respiratory system makes scientific investigation very challenging. The authors have simplified the complex problem into five components with these three areas as ones to address first: how the aerosol is (i) generated in a medical device, (ii) delivered to the patient, and (iii) deposited inside the lung. In this review, we discuss the technological advances and innovations made from experiments, simulations, and predictive models in each of these areas. In addition, we discuss the impact on patient treatment efficacy and recommend a clinical direction, with a focus on pediatrics. In each area, a series of research questions are posed and steps for future research to improve efficacy in aerosol drug delivery are outlined.

Application of Secondary Electrospray Ionization Coupled with High-Resolution Mass Spectrometry in Chemical Characterization of Thermally Generated Aerosols

Inhalation as a route for administering drugs and dietary supplements has garnered significant attention over the past decade. We performed real-time analyses of aerosols using secondary electrospray ionization (SESI) technology interfaced with high-resolution mass spectrometry (HRMS), primarily developed for exhaled breath analysis with the goal to detect the main aerosol constituents. Several commercially available inhalation devices containing caffeine, melatonin, cannabidiol, and vitamin B12 were tested. Chemical characterization of the aerosols produced by these devices enabled detection of the main constituents and screening for potential contaminants, byproducts, and impurities in the aerosol. In addition, a programmable syringe pump was connected to the SESI-HRMS system to monitor aerosolized active pharmaceutical ingredients (APIs) such as chloroquine, hydroxychloroquine, and azithromycin. This setup allowed us to detect caffeine, melatonin, hydroxychloroquine, chloroquine, and cannabidiol in the produced aerosols. Azithromycin and vitamin B12 in the aerosols could not be detected; however, our instrument setup enabled the detection of vitamin B12 breakdown products that were generated during the aerosolization process. Positive control was realized by liquid chromatography-HRMS analyses. The compounds detected in the aerosol were confirmed by exact mass measurements of the protonated and/or deprotonated species, as well as their respective collision-induced dissociation tandem mass spectra. These results reveal the potential wide application of this technology for the real-time monitoring of aerosolized active pharmaceutical ingredients that can be administered through the inhalation route.

Aqueous dispersions of oxygen nanobubbles for potential application in inhalation therapy

Inhalation is a non-invasive method of local drug delivery to the respiratory system. This study analyzed the potential use of aqueous dispersion of oxygen nanobubbles (ADON) as a drug carrier with the additional function of oxygen supplementation to diseased lungs. The suitability of the membrane-based method of ADON preparation and, next, the stability of ADON properties during storage and after aerosolization in nebulizers of various designs (jet, ultrasonic, and two vibrating mesh devices) was investigated. The increased oxygen content in the aerosol generated in two mesh nebulizers suggests that the proposed concept may be helpful in the oxygen supplementation during drug delivery by aerosol inhalation without using an additional oxygen source. This application can increase the overall effectiveness of lung disease treatment and pulmonary rehabilitation.

Optimization and Application of an Efficient and Stable Inhalation Exposure System for Rodents

Inhalation is a promising and challenging method in pharmaceutical and biological science research. A stable environment is critical in dynamic inhalation administration. However, the establishment of a stable inhalation system is very challenging. Indacaterol glycopyrronium bromide inhalation powder (IM/GP mixed powder) is composed of indacaterol maleate and glycopyrronium bromide powder to treat chronic obstructive pulmonary disease (COPD). The aim of this study is to build suitable inhalation conditions and then to evaluate the pulmonary safety of this drug in Sprague-Dawley(SD) rats. In the research, through the coordination of the atomization flow, air pump flow, and scraper speed, aerosols were stabilized at 200 ± 20% mg/m³, and then rats were nose-only administered with the IM/GP mixed powder, Ultibro, and lactose-magnesium stearate mixed powder at 2.6 mg/kg/day for 14 days and 14 days of recovery period, respectively. After exposure, hematology, inflammatory cytokines in rats bronchoalveolar lavage fluid (BALF) and serum, histopathological examination were performed. Results showed that the stability of powder aerosols can be realized under the atomization generation flow: 10 L/min, sampling flow: 2 L/min, system pumping capacity: 10 L/min and powder scraper speed: 8-10 L/min, and there were no significant adverse effects on body weight, clinic signs, hematology, and pathology in rats. Overall, the results suggested that the IM/GP mixed powder inhalation at the dose of 2.6 mg/kg/d can be reached when the aerosol concentration is within the range of 200 ± 20% mg/m³, and there were no pulmonary toxicity effects in rats.

Analysis of the Consumption of Drugs Prescribed for the Treatment of Asthma in Belgian Children

(1) Asthma is one of the most common chronic diseases in the world among children. The main purpose of this study was to analyze the consumption of asthma medications in order to investigate asthma in children (2-18 years) and the association with health care consumption; (2) a retrospective study using anonymized administrative data for 2013-2018 from the third largest Belgian health insurer was conducted; (3) in 2018, 12.9% of children received at least one asthma medication and 4.4% received at least two packages with a minimum of 30 days between purchases. Preschool children (2-6 years) were three times more likely to take asthma medication than older children (7-18 years). ICS, in combination or not with LABA, were the most dispensed drugs among children. Children with asthma medications were almost twice as likely to receive antibiotics, more likely to end up in the emergency room, and twice as likely to be hospitalized; (4) most children took ICS, according to the GINA guidelines. High rates of nebulization in young children were observed, despite the recommendation to use an inhaler with a spacing chamber as much as possible. Finally, children who took asthma medications were more likely to end up in the ER or be hospitalized.

Nebulizer systems: a new frontier for therapeutics and targeted delivery

Drug delivery via the pulmonary route is a cornerstone in the pharmaceutical sector as an alternative to oral and parenteral administration. Nebulizer inhalation treatment offers multiple drug administration, easily employed with tidal breathing, suitable for children and elderly, can be adapted for severe patients and visible spray ensures patient satisfaction. This review discusses the operational and mechanical characteristics of nebulizer delivery devices in terms of aerosol production processes, their usage, benefits and drawbacks that are currently shaping the contemporary landscape of inhaled drug delivery. With the advent of particle engineering, novel inhaled nanosystems can be successfully developed to increase lung deposition and decrease pulmonary clearance. The above-mentioned advances might pave the path for treating a life-threatening disorder like severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which is also discussed in the current state of the art.

Dry Powder Inhalers in the Digitalization Era: Current Status and Future Perspectives

During the last decades, the term "drug delivery systems" (DDSs) has almost fully replaced previously used terms, such as "dosage forms", in an attempt to emphasize the importance of the drug carrier in ensuring the claimed safety and effectiveness of the product. However, particularly in the case of delivery devices, the term "system", which by definition implies a profound knowledge of each single part and their interactions, is not always fully justified when using the DDS term. Within this context, dry powder inhalers (DPIs), as systems to deliver drugs via inhalation to the lungs, require a deep understanding of the complex formulation-device-patient interplay. As of now and despite the progress made in particle engineering and devices design, DPIs' clinical performance is limited by variable patients' breathing patterns. To circumvent this pitfall, next-generation DPIs should ideally adapt to the different respiratory capacity of individuals across age, health conditions, and other related factors. In this context, the recent wave of digitalization in the health care and industrial sectors may drive DPI technology towards addressing a personalized device-formulation-patient liaison. In this review, evolving technologies are explored and analyzed to outline the progress made as well as the gaps to fill to align novel DPIs technologies with the systems theory approach.

Inhaled aerosols: Their role in COVID-19 transmission, including biophysical interactions in the lungs

The high rate of spreading of COVID-19 is attributed to airborne particles exhaled by infected but often asymptomatic individuals. In this review, the role of aerosols in SARS-CoV-2 coronavirus transmission is discussed from the biophysical perspective. The essential properties of the coronavirus virus transported inside aerosol droplets, their successive inhalation, and size-dependent deposition in the respiratory system are highlighted. The importance of face covers (respirators and masks) in the reduction of aerosol spreading is analyzed. Finally, the discussion of the physicochemical phenomena of the coronavirus entering the surface of lung liquids (bronchial mucus and pulmonary surfactant) is presented with a focus on a possible role of interfacial phenomena in pulmonary alveoli. Information given in this review should be important in understanding the essential biophysical conditions of COVID-19 infection via aerosol route as a prerequisite for effective strategies of respiratory tract protection, and possibly, indications for future treatments of the disease.

Medical devices in allergy practice

Medical devices provide people with some health benefits in terms of diagnosis, prevention, treatment, and monitoring of disease processes. Different medical specialties use varieties of medical devices more or less specific for them. Allergology is an interdisciplinary field of medical science and teaches that allergic reactions are of systemic nature but can express themselves at the level of different organs across the life cycle of an individual. Subsequently, medical devices used in allergology could be regarded as: 1) general, servicing the integral diagnostic and management principles and features of allergology, and 2) organ specific, which are shared by organ specific disciplines like pulmonology, otorhinolaryngology, dermatology, and others. The present position paper of the World Allergy Organization (WAO) is meant to be the first integral document providing structured information on medical devices in allergology used in daily routine but also needed for sophisticated diagnostic purposes and modern disease management. It is supposed to contribute to the transformation of the health care system into integrated care pathways for interrelated comorbidities.

Preclinical Development of Orally Inhaled Drugs (OIDs)-Are Animal Models Predictive or Shall We Move Towards In Vitro Non-Animal Models?

Respiratory diseases constitute a huge burden in our society, and the global respiratory drug market currently grows at an annual rate between 4% and 6%. Inhalation is the preferred administration method for treating respiratory diseases, as it: (i) delivers the drug directly at the site of action, resulting in a rapid onset; (ii) is painless, thus improving patients' compliance; and (iii) avoids first-pass metabolism reducing systemic side effects. Inhalation occurs through the mouth, with the drug generally exerting its therapeutic action in the lungs. In the most recent years, orally inhaled drugs (OIDs) have found application also in the treatment of systemic diseases. OIDs development, however, currently suffers of an overall attrition rate of around 70%, meaning that seven out of 10 new drug candidates fail to reach the clinic. Our commentary focuses on the reasons behind the poor OIDs translation into clinical products for the treatment of respiratory and systemic diseases, with particular emphasis on the parameters affecting the predictive value of animal preclinical tests. We then review the current advances in overcoming the limitation of animal animal-based studies through the development and adoption of in vitro, cell-based new approach methodologies (NAMs).

An Efficient and Cost-Effective Nose-Only Inhalational Chamber for Rodents: Design, Optimization and Validation

The mainstay treatment of pulmonary disorders lies around the direct drug targeting to the lungs using a nebulizer, metered-dose inhaler, or dry powder inhaler. Only few inhalers are available in the market that could be used for inhalational drug delivery in rodents. However, the available rodent inhalers invariably require high cost and maintenance, which limits their use at laboratory scale. The present work, therefore, was undertaken to develop a simple, reliable, and cost-effective nose-only inhalation chamber with holding capacity of three mice at a time. The nebulized air passes directly and continuously from the central chamber to mouthpiece and maintains an aerosol cloud for rodents to inhale. Laser diffraction analysis indicated volume mean diameter of 4.02 ± 0.30 μm, and the next-generation impactor studies, however, revealed mean mass aerodynamic diameter of 3.40 ± 0.27 μm, respectively. An amount of 2.05 ± 0.20 mg of voriconazole (VRC) was available for inhalation at each delivery port of the inhaler. In vivo studies indicated the deposition of 76.12 ± 19.50 μg of VRC in the mice lungs when nebulized for a period of 20 min. Overall, the developed nose-only inhalation chamber offers a reliable means of generating aerosols and successfully exposing mice to nebulization.

Aerosol Characteristics and Physico-Chemical Compatibility of Combivent® (Containing Salbutamol and Ipratropium Bromide) Mixed with Three Other Inhalants: Budesonide, Beclomethasone or N-Acetylcysteine

Inhalation therapy with a nebulizer is widely used in chronic respiratory disease. Mixing inhalation solutions/suspensions for simultaneous inhalation is more convenient and might simplify the administration procedure. However, there are no data available to address the in vitro aerosol characteristics and physico-chemical compatibility of Combivent^® (containing Salbutamol and Ipratropium bromide) with other inhalation solutions/suspensions. In order to investigate the in vitro aerosol characteristics and physico-chemical compatibility of Combivent^® with Budesonide, Beclomethasone, and N-acetylcysteine, the appearance, pH, osmotic pressure, chemical stability, mass median aerodynamic diameter (MMAD), fine particles fraction (FPF), particle size corresponding to X50 (particle size, which accounts for 50% of the total cumulative percentage of volume of all particles), delivery rate, and total delivery of the mixed inhalation solution/suspension were tested. There was no change in the appearance such as a change in color or precipitation formation at room temperature. The pH, osmolality, and chemicals of the mixtures were stable for 24 h after mixing. There were no significant differences between Combivent^®, Budesonide, Beclomethasone, N-acetylcysteine, and the mixtures in MMAD, FPF, X50, the delivery rate, and the total delivery. This indicates that the mixtures were physically and chemically compatible. The mixing did not influence the particle size, distribution, or delivery compatibility of the mixtures.

Recent advances in aerosolised drug delivery

Pulmonary route is extensively studied for the diagnosis and treatment of pulmonary and extra pulmonary disease conditions such as asthma, tuberculosis, emphysema, and bronchitis. Formulation design, inhalation device and particle size play key role in determining the aerosol performance. The lack of desired clinical outcome along with the problem regarding efficacy or any adverse drug effect may arise due to improper training and education in use of the device to control the actuation and aerosol inhalation. This review summarizes the difference in the mechanistic features of current marketed aerosol delivery devices with respect to mechanism of aerosol generation with possible advancements in the aerosol design. The delivery options in the pulmonary route and its merits together with the limitations are also discussed. An update is provided regarding the current research and clinical outcome of the use of inhalational technology.

Inspiromatic-safety and efficacy study of a new generation dry powder inhaler in asthmatic children

BACKGROUND

Dry powder inhalers (DPI) are effective but forceful inhalation required to fluidize the powder may be difficult for children and patients with airway disease. Inspiromatic is a new generation active DPI that actively suspends drugs in synchrony with inhalation. We evaluated safety and efficacy of Formoterol delivery via Inspiromatic, compared to Aerolizer, a conventional DPI, in pediatric asthmatic subjects.

METHODS

A phase I/II, randomized, single-center, double-blind, double-dummy, placebo-controlled, cross-over study. Subjects aged 8-18 years with FEV₁ 40-80% predicted were included. Patients were randomized to inhale Formoterol via the Inspiromatic, immediately followed by the placebo via the Aerolizer or vice versa, in a double-blind fashion. Spirometry, blood pressure, and heart rate were measured at baseline and 15, 30, and 60 min after drug administration. Capsule emptying, comfort of use, confidence in efficacy, and patient satisfaction were assessed. At a subsequent visit, three months later, patients inhaled the active drug via the other DPI.

RESULTS

Twenty-nine patients, aged 12.6 (±2.3) years, mean (SD), completed the study. Baseline FEV₁ was 69.1 (±6.7) % at visit one and 65.3 (±9) % at visit two. Maximal FEV₁ increase was 16.6 (±7.1) % with Inspiromatic and 15.5 (±7.5) % with Aerolizer (P = 0.47). No differences in heart rate or blood pressure were observed; 24/28 capsules were emptied using the Inspiromatic and 19/28 with the Aerolizer (P = 0.5); 21/28 preferred the Inspiromatic and 7/28 the Aerolizer (P < 0.001). There were no adverse events.

CONCLUSIONS

Formoterol inhalation via the Inspiromatic is safe and as efficacious as with the Aerolizer. The device is well accepted by asthmatic subjects.

Particle Size Dynamics: Toward a Better Understanding of Electronic Cigarette Aerosol Interactions With the Respiratory System

The knowledge of possible acute and long-term health effects of aerosols inhaled from electronic cigarettes (ECs) is still limited partially due to incomplete awareness of physical phenomena related to EC-aerosol dynamics. This short review discusses the basic processes of aerosol transformation (dynamics) upon inhalation, indicating also the need for the accurate determination of the size of droplets in the inhaled EC-mist. The significance of differences in the aerosol particle size distribution for the prediction of regional deposition of inhaled mist in the respiratory system is highlighted as a decisive factor in the interactions of inhaled EC-aerosols with the organism.

The impact of nasal aspiration with an automatic device on upper and lower respiratory symptoms in wheezing children: a pilot case-control study

Background

The impact of proper aspiration of nasal secretions during upper respiratory infection on the frequency and severity of symptoms of lower airways has never been investigated. The study was aimed at testing if cleaning the nasal cavities of children with recurrent wheezing using an automatic nasal aspirator improves the upper and lower respiratory symptoms during the cold season.

Methods

Parents of wheezing children (age 3-72 mo.) answered questionnaires and learned using a nebulizer equipped (cases) or not equipped (controls) with an automatic nasal aspirator (DuoBaby, OMRON, Japan). During a 90-days monitoring period parents filled an electronic diary (BreathMonitor, TPS, Rome, Italy) on their child’s symptoms of the upper and lower airways.

Results

Eighty-nine/91 patients (43 cases, 46 controls) completed the study. Less days with upper (25.0% vs 46.4%, p = 0.004) or lower (21.8% vs 32.8%, p = 0.022) airways symptoms and less days with salbutamol inhalation (12.2% vs 16.9%, p < 0.001) were reported by cases than by controls. The episodes of upper respiratory symptoms were shorter [4.3 days (95%CI:3.8–4.9) vs 5.7 days (95%CI:5.0–6.4), p = 0.007] but not less frequent [2.3 (95%CI: 1.8–2.8) vs 2.6 (95%CI:2.2–3.0), p = 0.122] among cases than among controls. Similarly, the episodes of lower respiratory symptoms tended to be shorter [3.8 days, (95%CI: 3.4–4.2) vs 4.4 days, (95%CI: 4.4–6.0), p = 0.067] but not less frequent [1.9 (95%CI:1.5–2.3) vs 2.1 (95%CI:1.7–2.4), p = 0.240] among the group using the nasal aspirator.

Conclusions

In our pilot study, the use of an automatic nasal aspirator in children with a history of recurrent wheezing was associated with an improved respiratory health during the cold season.

Electronic supplementary material

The online version of this article (10.1186/s13052-018-0489-6) contains supplementary material, which is available to authorized users.

Objective Assessment of Patient Inhaler User Technique Using an Audio-Based Classification Approach

Many patients make critical user technique errors when using pressurised metered dose inhalers (pMDIs) which reduce the clinical efficacy of respiratory medication. Such critical errors include poor actuation coordination (poor timing of medication release during inhalation) and inhaling too fast (peak inspiratory flow rate over 90 L/min). Here, we present a novel audio-based method that objectively assesses patient pMDI user technique. The Inhaler Compliance Assessment device was employed to record inhaler audio signals from 62 respiratory patients as they used a pMDI with an In-Check Flo-Tone device attached to the inhaler mouthpiece. Using a quadratic discriminant analysis approach, the audio-based method generated a total frame-by-frame accuracy of 88.2% in classifying sound events (actuation, inhalation and exhalation). The audio-based method estimated the peak inspiratory flow rate and volume of inhalations with an accuracy of 88.2% and 83.94% respectively. It was detected that 89% of patients made at least one critical user technique error even after tuition from an expert clinical reviewer. This method provides a more clinically accurate assessment of patient inhaler user technique than standard checklist methods.

Efficacy and usability of a novel nebulizer targeting both upper and lower airways

Background

Upper and lower airways diseases share in part their pathogenic mechanisms and frequently occur simultaneously as “United Airway Disease.” Local treatment with nebulizers delivers anti-symptomatic drugs in either the upper or the lower airways, according to the particle size generated by the nebulizer. To our knowledge, no nebulizer combines both application ways.

The aim of this study is to test the efficacy and usability of a new nebulizer (OMRON A3 complete), generating aerosols with particles diameters of 2-4.5 μm, 4.5-7.5 μm or >7.5 μm, according to the user’s choice.

Methods

Seventy-seven patients between 5 and 17 years of age with a diagnosis of rhinitis or asthma were examined. Oxymetazoline or Salbutamol were prescribed according to best clinical practice guidelines. Both drugs were administered through the OMRON A3 Complete nebulizer, with a particle dimension of >7.5 μm to treat nasal obstruction and 2-4.5 μm for bronchial obstruction. The efficacy of treatment was assessed by total nasal inspiratory airflow and FEV-1, Tiffeneau index (FEV1/FVC) and MMEF 25/75 respectively, 10 min before and after treatment. Symptom improvement and usability were measured by patients’ and doctors’ questionnaires.

Results

Overall, 77 patients seeking care for acute respiratory symptoms were assigned to the upper (n = 39) or lower (n = 38) airways disease group. For symptoms of the upper airways, 92% (95% CI, 77-97%) of the patients reported subjective improvement, while 87% (95% CI, 73-94%) did so for the lower airways. The average total nasal inspiratory airflow improved significantly (p = 0.030) among the patients with upper airways symptoms, from 275 ml/s (95% CI, 207-342 ml/s) to 359 ml/s (95% CI, 300-419 ml/s) after Oxymetazoline administration. All selected lung function parameters (FEV1, Tiffeneau Index and MMEF25-75) significantly improved among the patients with lower airways symptoms after inhalation of Salbutamol (p < 0.001). The nebulizer was assessed as “easy to use” by over 95% of participants in both groups.

Conclusions

The OMRON A3 efficiently delivers anti-symptomatic drugs in both upper and lower airways in a user-friendly way. This device may be useful to facilitate adherence to a complete treatment of respiratory symptoms in patients with symptoms of the so-called United Airway Disease.

Considerations in establishing bioequivalence of inhaled compounds

INTRODUCTION

Generic inhalers are often perceived as inferior to their branded counterparts; however, they are safe and effective if they can meet the regulatory requirements. The approach to assess bioequivalence (BE) in oral dosage form products is not sufficient to address the complexities of inhalational products (e.g., patient-device interface); hence, more considerations are needed and caution should be applied in determining BE of inhaled compounds.

AREAS COVERED

This review outlines the evaluation process for generic inhalers, explores the regulatory approaches in BE assessment, and highlights the considerations and challenges in the current in vitro and in vivo approaches (lung deposition, pharmacokinetic, pharmacodynamic/clinical studies, and patient-device interface) for establishing BE of inhaled compounds.

EXPERT OPINION

The ultimate goals in this field are to establish uniformity in the regulatory approaches to speed the drug submission process in different regions, clear physicians' misconception of generic inhalers, and have meaningful clinical endpoints such as improvement in patient quality of life when compared to placebo and brand name drugs. As inhalational drugs become more common for other indications such as antibiotics, the technologies developed for inhaled compounds in the treatment of chronic pulmonary diseases may be extrapolated to these other agents.

Advances in Audio-Based Systems to Monitor Patient Adherence and Inhaler Drug Delivery

Hundreds of millions of people worldwide have asthma and COPD. Current medications to control these chronic respiratory diseases can be administered using inhaler devices, such as the pressurized metered dose inhaler and the dry powder inhaler. Provided that they are used as prescribed, inhalers can improve patient clinical outcomes and quality of life. Poor patient inhaler adherence (both time of use and user technique) is, however, a major clinical concern and is associated with poor disease control, increased hospital admissions, and increased mortality rates, particularly in low- and middle-income countries. There are currently limited methods available to health-care professionals to objectively and remotely monitor patient inhaler adherence. This review describes recent sensor-based technologies that use audio-based approaches that show promising opportunities for monitoring inhaler adherence in clinical practice. This review discusses how one form of sensor-based technology, audio-based monitoring systems, can provide clinically pertinent information regarding patient inhaler use over the course of treatment. Audio-based monitoring can provide health-care professionals with quantitative measurements of the drug delivery of inhalers, signifying a clear clinical advantage over other methods of assessment. Furthermore, objective audio-based adherence measures can improve the predictability of patient outcomes to treatment compared with current standard methods of adherence assessment used in clinical practice. Objective feedback on patient inhaler adherence can be used to personalize treatment to the patient, which may enhance precision medicine in the treatment of chronic respiratory diseases.