Lung Deposition and Inspiratory Flow Rate in Patients with Chronic Obstructive Pulmonary Disease Using Different Inhalation Devices: A Systematic Literature Review and Expert Opinion

Budesonide/formoterol turbuhaler vs pMDI salbutamol for acute asthma in outpatient emergency department: a prospective, randomized, open-label study

BACKGROUND

The Global Initiative for Asthma (GINA) has suggested the need for more studies on inhaled corticosteroid (ICS)-formoterol in the Emergency Department (ED).

OBJECTIVES

We aimed to compare the outcomes of budesonide/formoterol (160/4.5 mcg/inhalation) turbuhaler versus pressurized metered-dose inhaler (pMDI) salbutamol (100 mcg/puff) in acute asthma in the outpatient ED.

METHODS

This single-centre, prospective, randomized, and open-label study involved adult asthma patients with mild to moderate asthma exacerbation who attended the outpatient ED of a tertiary hospital in Malaysia. The intervention arm received budesonide/formoterol (Symbicort® 160/4.5 mcg) turbuhaler, while the control arm received pMDI salbutamol with a valved holding chamber. Stratified randomization with variable baseline ICS use was employed. Direct discharge rate from outpatient ED was the primary outcome. Vital signs pre- and post-treatment between the two arms were also compared.

RESULTS

Seventy-four (n = 37 for each arm) asthma patients were recruited. Baseline clinical characteristics were comparable between the two arms. Direct discharge rates from ED were comparable between the intervention (94.6%) and the control (91.9%) arms (p = 1.000). Post-treatment outcomes (respiratory rate, oxygen saturation, peak expiratory flow rate) were similar between the two arms, except for the higher increment of heart rate (p < 0.001) and lesser reduction of blood pressure in the control arm (p = 0.013). Intravenous hydrocortisone use was significantly higher in the control arm (n = 19, 51.4%) than in the budesonide/formoterol arm (n = 6, 16.2%) (p = 0.001).

CONCLUSION

Budesonide/formoterol turbuhaler is as effective as pMDI salbutamol in treating asthma exacerbation in the outpatient ED with less effect on heart rate and lower usage of intravenous corticosteroids.

Scale-Up and Postapproval Changes in Orally Inhaled Drug Products: Scientific and Regulatory Considerations

Approved drug products may be subject to change(s) for a variety of reasons. The changes may include, but are not limited to, increase in batch size, alteration of the drug product constituent(s), improvement in the manufacturing process, and shift in manufacturing sites. The extent of pharmaceutical testing and the regulatory pathway for timely implementation of any change in the approved product and/or process depends upon the nature and extent of change. The U.S. Food and Drug Administration (FDA) has published guidelines that outline its expectations for the Scale-Up and Postapproval Changes (SUPAC) in the solid oral immediate and modified release (MR) products, and semisolid formulations. However, to date, no such guidelines have been issued to address SUPAC in the orally inhaled drug products (OIDPs), and this article represents a seminal contribution in this direction. It is hoped that it will inspire contributions from the relevant multidisciplinary experts from the pharmaceutical industry and the agency in accomplishing formal regulatory guidelines relevant to the OIDP SUPAC. The OIDPs are complex drug-device combination products. Therefore, a conceptualization of SUPAC guidelines for these products warrants consideration of contributions of effect of change(s) in individual components (drug substance, formulation, device) as well as a compound effect that a single or multiple changes may have on product performance, and its safety and efficacy. This article provides a discussion of scientific aspects and regulatory bases relevant to the development of SUPAC for OIDPs, and it attempts to outline considerations that may be applicable in addressing issues related to the OIDP SUPAC in the context of human drugs. The authors' statements should not be viewed as recommendations from any regulatory agency, as the applicable guidelines would be determined on case-by-case evaluation by the relevant authorities.

Recalibrating Perceptions and Attitudes Toward Nebulizers versus Inhalers for Maintenance Therapy in COPD: Past as Prologue

Aerosol therapy administered via handheld inhaler or nebulizer device has long been standard for the treatment of chronic obstructive pulmonary disease (COPD), both for maintenance therapy and for management of acute exacerbations. Of the 2 options for drug delivery, inhaler devices are the most widely used for ambulatory patients with COPD as they are small, portable, and convenient and offer an array of medication options. They are, however, prone to suboptimal inhalation technique and use errors, which decrease the amount of medication delivered, compromise efficacy, and adversely affect clinical outcomes. Nebulizers are less often employed for aerosol delivery than inhalers, particularly in the home environment. Considered bulky and expensive, nebulizers have historically had limited medication options compared with inhalers. Nonetheless, nebulizers may be preferred over inhalers in specific patient populations, such as in patients with poor lung function, lack of hand-breath coordination, or cognitive impairment. Furthermore, technological advances and development of new nebulizer-compatible medications are shifting the benefit equation for nebulizers versus inhalers in a way that merits reconsideration of the role of nebulizers in the maintenance treatment of COPD. Using the available literature, this state-of-the-art review critically evaluates the benefits and limitations of aerosol therapy delivery via inhaler or nebulizer for patients with COPD; describes the factors that may influence the benefit equation, including current advances in nebulizer technology and future developments; and provides insights on implementation of nebulizer therapy in clinical practice.

Challenges and Opportunities in COPD Management in Latin America: A Review of Inhalation Therapies and Advanced Drug Delivery Systems

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide, particularly in low- and middle-income countries, where it poses a significant burden. In Latin America, the estimated prevalence of COPD is notably high, but the management and treatment of the disease have progressed slowly. This review examines the current status of inhalation therapy for COPD in Latin America, focusing on pharmacological therapies, inhalation devices, and the potential of advanced drug delivery systems. Pharmacological management predominantly relies on inhaled bronchodilators and corticosteroids, though access to these therapies varies considerably across the region. Inhalation devices, such as metered-dose inhalers (MDIs) and dry powder inhalers (DPIs), play a critical role in effective treatment delivery. However, their usage is often compromised by incorrect technique, low adherence, and limited availability, especially for DPIs. Emerging technologies, including nanoformulations, represent a promising frontier for the treatment of COPD by improving drug delivery and reducing side effects. However, significant barriers, such as high development costs and inadequate infrastructure, hinder their widespread adoption in the region. This review highlights the need for a multifaceted approach to enhance COPD management in Latin America, including optimizing access to existing inhalation therapies, strengthening healthcare infrastructure, improving provider training, and engaging patients in treatment decisions. Overcoming these challenges is crucial to improving COPD outcomes across the region.

Inhalational Drug Devices: Revisiting the Linchpin of Asthma Management

Asthma remains a prevalent condition among all age groups globally. First-line treatment requires the delivery of medications into the distal respiratory tract via inhalers. Using appropriate inhaler techniques is a significant challenge in achieving disease control. A variety of inhalers are available for treating asthma, and selecting the appropriate inhaler type for any given patient is crucial to achieving and maintaining symptomatic control. This review will discuss the anatomy and physiology behind drug delivery via inhalers, the types of inhalers currently available for use, nebulizers, and future directions in the delivery of inhaled medications for asthma.

The effects of airway disease on the deposition of inhaled drugs

INTRODUCTION

The deposition of inhaled medications is the first step in the pulmonary pharmacokinetic process to produce a therapeutic response. Not only lung dose but more importantly the distribution of deposited drug in the different regions of the lung determines local bioavailability, efficacy, and clinical safety. Assessing aerosol deposition patterns has been the focus of intense research that combines the fields of physics, radiology, physiology, and biology.

AREAS COVERED

The review covers the physics of aerosol transport in the lung, experimental, and in-silico modeling approaches to determine lung dose and aerosol deposition patterns, the effect of asthma, chronic obstructive pulmonary disease, and cystic fibrosis on aerosol deposition, and the clinical translation potential of determining aerosol deposition dose.

EXPERT OPINION

Recent advances in in-silico modeling and lung imaging have enabled the development of realistic subject-specific aerosol deposition models, albeit mainly in health. Accurate modeling of lung disease still requires additional refinements in existing imaging and modeling approaches to better characterize disease heterogeneity in peripheral airways. Nevertheless, recent patient-centric innovation in inhaler device engineering and the incorporation of digital technology have led to more consistent lung deposition and improved targeting of the distal airways, which better serve the clinical needs of patients.

Current approaches in smart nano-inspired drug delivery: A narrative review

Background and Aim

The traditional drug delivery approach involves systemic administration of a drug that could be nonspecific in targeting, low on efficacy, and with severe side-effects. To address such challenges, the field of smart drug delivery has emerged aiming at designing and developing delivery systems that can target specific cells, tissues, and organs and have minimal off-target side-effects.

Methods

A literature search was done to collate papers and reports about the currently available various strategies for smart nano-inspired drug delivery. The databases searched were PubMed, Scopus, and Google Scholar. Based on selection criteria, the most pertinent and recent items were included.

Results

Smart drug delivery is a cutting-edge revolutionary intervention in modern medicines to ensure effective and safe administration of therapeutics to target sites. These hold great promise for targeted and controlled delivery of therapeutic agents to improve the efficacy with reduced side-effects as compared to the conventional drug delivery approaches. Current smart drug delivery approaches include nanoparticles, liposomes, micelles, and hydrogels, each with its own advantages and limitations. The success of these delivery systems lies in engineering and designing them, and optimizing their pharmacokinetics and pharmacodynamics properties.

Conclusion

Development of drug delivery systems that can get beyond various physiological and clinical barriers, as observed in conventionally administered chemotherapeutics, has been possible through recent advancements. Using multifunctional targeting methodologies, smart drug delivery tries to localize therapy to the target location, reduces cytotoxicity, and improves the therapeutic index. Rapid advancements in research and development in smart drug delivery provide wider and more promising avenues to guarantee a better healthcare system, improve patient outcomes, and achieve higher levels of effective medical interventions like personalized medicine.

Aerosol Plumes of Inhalers Used in COPD

INTRODUCTION

The selection of inhaler device is of critical importance in chronic obstructive pulmonary disease (COPD) as the interaction between a patient's inhalation profile and the aerosol characteristics of an inhaler can affect drug delivery and lung deposition. This study assessed the in vitro aerosol characteristics of inhaler devices approved for the treatment of COPD, including a soft mist inhaler (SMI), pressurized metered-dose inhalers (pMDIs), and dry powder inhalers (DPIs).

METHODS

High-speed video recording was used to visualize and measure aerosol velocity and spray duration for nine different inhalers (one SMI, three pMDIs, and five DPIs), each containing dual or triple fixed-dose combinations of long-acting muscarinic receptor antagonists and long-acting β2-agonists, with or without an inhaled corticosteroid. Measurements were taken in triplicate at experimental flow rates of 30, 60, and 90 l/min. Optimal flow rates were defined based on pharmacopoeial testing requirements: 30 l/min for pMDIs and SMIs, and the rate achieving a 4-kPa pressure drop against internal inhaler resistance for DPIs. Comparison of aerosol plumes was based on the experimental flow rates closest to the optimal flow rates.

RESULTS

The Respimat SMI had the slowest plume velocity (0.99 m/s) and longest spray duration (1447 ms) compared with pMDIs (velocity: 3.65-5.09 m/s; duration: 227-270 ms) and DPIs (velocity: 1.43-4.60 m/s; duration: 60-757 ms). With increasing flow rates, SMI aerosol duration was unaffected, but velocity increased (maximum 2.63 m/s), pMDI aerosol velocity and duration were unaffected, and DPI aerosol velocity tended to increase, with a more variable impact on duration.

CONCLUSIONS

Aerosol characteristics (velocity and duration of aerosol plume) vary by inhaler type. Plume velocity was lower and spray duration longer for the SMI compared with pMDIs and DPIs. Increasing experimental flow rate was associated with faster plume velocity for DPIs and the SMI, with no or variable impact on plume duration, whereas pMDI aerosol velocity and duration were unaffected by increasing flow rate.

Demystifying Dry Powder Inhaler Resistance with Relevance to Optimal Patient Care

The selection of an inhaler device is a key component of respiratory disease management. However, there is a lack of clarity surrounding inhaler resistance and how it impacts inhaler selection. The most common inhaler types are dry powder inhalers (DPIs) that have internal resistance and pressurised metered dose inhalers (pMDIs) that use propellants to deliver the drug dose to the airways. Inhaler resistance varies across the DPIs available on the market, depending largely on the design geometry of the device but also partially on formulation parameters. Factors influencing inhaler choice include measures such as flow rate or pressure drop as well as inhaler technique and patient preference, both of which can lead to improved adherence and outcomes. For optimal disease outcomes, device selection should be individualised, inhaler technique optimised and patient preference considered. By addressing the common clinically relevant questions, this paper aims to demystify how DPI resistance should guide the selection of the right device for the right patient.

Implementing an Evidence-Based COPD Hospital Discharge Protocol: A Narrative Review and Expert Recommendations

Discharge bundles, comprising evidence-based practices to be implemented prior to discharge, aim to optimise patient outcomes. They have been recommended to address high readmission rates in patients who have been hospitalised for an exacerbation of chronic obstructive pulmonary disease (COPD). Hospital readmission is associated with increased morbidity and healthcare resource utilisation, contributing substantially to the economic burden of COPD. Previous studies suggest that COPD discharge bundles may result in fewer hospital readmissions, lower risk of mortality and improvement of patient quality of life. However, evidence for their effectiveness is inconsistent, likely owing to variable content and implementation of these bundles. To ensure consistent provision of high-quality care for patients hospitalised with an exacerbation of COPD and reduce readmission rates following discharge, we propose a comprehensive discharge protocol, and provide evidence highlighting the importance of each element of the protocol. We then review care bundles used in COPD and other disease areas to understand how they affect patient outcomes, the barriers to implementing these bundles and what strategies have been used in other disease areas to overcome these barriers. We identified four evidence-based care bundle items for review prior to a patient's discharge from hospital, including (1) smoking cessation and assessment of environmental exposures, (2) treatment optimisation, (3) pulmonary rehabilitation, and (4) continuity of care. Resource constraints, lack of staff engagement and knowledge, and complexity of the COPD population were some of the key barriers inhibiting effective bundle implementation. These barriers can be addressed by applying learnings on successful bundle implementation from other disease areas, such as healthcare practitioner education and audit and feedback. By utilising the relevant implementation strategies, discharge bundles can be more (cost-)effectively delivered to improve patient outcomes, reduce readmission rates and ensure continuity of care for patients who have been discharged from hospital following a COPD exacerbation.

Drug combinations for inhalation: Current products and future development addressing disease control and patient compliance

Pulmonary delivery is an alternative route of administration with numerous advantages over conventional routes of administration. It provides low enzymatic exposure, fewer systemic side effects, no first-pass metabolism, and concentrated drug amounts at the site of the disease, making it an ideal route for the treatment of pulmonary diseases. Owing to the thin alveolar-capillary barrier, and large surface area that facilitates rapid absorption to the bloodstream in the lung, systemic delivery can be achieved as well. Administration of multiple drugs at one time became urgent to control chronic pulmonary diseases such as asthma and COPD, thus, development of drug combinations was proposed. Administration of medications with variable dosages from different inhalers leads to overburdening the patient and may cause low therapeutic intervention. Therefore, products that contain combined drugs to be delivered via a single inhaler have been developed to improve patient compliance, reduce different dose regimens, achieve higher disease control, and boost therapeutic effectiveness in some cases. This comprehensive review aimed to highlight the growth of drug combinations by inhalation over time, obstacles and challenges, and the possible progress to broaden the current options or to cover new indications in the future. Moreover, various pharmaceutical technologies in terms of formulation and device in correlation with inhaled combinations were discussed in this review. Hence, inhaled combination therapy is driven by the need to maintain and improve the quality of life for patients with chronic respiratory diseases; promoting drug combinations by inhalation to a higher level is a necessity.

Predicting Inhaled Drug Dose Generated by Mesh Nebulizers

Background: The lung dose of nebulized drugs for spontaneous breathing is influenced by breathing patterns and nebulizer performance. This study aimed to develop a system for measuring breath patterns and a formula for estimating inhaled drugs, and then to validate the hypothesized prediction formula. Methods: An in vitro model was first used to determine correlations among the delivered dose, breath patterns, and doses deposited on the accessories and reservoirs testing with a breathing simulator to generate 12 adult breathing patterns (n = 5). A pressure sensor was developed to measure breathing parameters and used along with a prediction formula that accounted for the initial charge dose, respiratory pattern, and dose on the accessory and reservoir of a nebulizer. Three brands of nebulizers were tested by placing salbutamol (5.0 mg/2.5 mL) in the drug holding chamber. Ten healthy individuals participated in the ex vivo study to validate the prediction formula. The agreement between the predicted and inhaled doses was analyzed using the Bland-Altman plot. Results: The in vitro model showed that the inspiratory time to total respiratory cycle time (Ti/Ttotal; %) was significantly directly correlated with the delivered dose among the respiratory factors, followed by inspiratory flow, respiratory rate, and tidal volume. The ex vivo model showed that Ti/Ttotal was significantly directly correlated with the delivered dose among the respiratory factors, in addition to the nebulization time and accessory dose. The Bland-Altman plots for the ex vivo model showed similar results between the two methods. Large differences in inhaled dose measured at the mouth were observed among the subjects, ranging from 12.68% to 21.68%; however, the difference between the predicted dose and inhaled dose was lower, at 3.98%-5.02%. Conclusions: The inhaled drug dose could be predicted with the hypothesized estimation formula, which was validated by the agreement between the inhaled and predicted doses of breathing patterns of healthy individuals.

Modeling of pulmonary deposition of agents of open and fixed dose triple combination therapies through two different low-resistance inhalers in COPD: a pilot study

Introduction

Inhalation therapy is a cornerstone of treating patients with chronic obstructive pulmonary disease (COPD). Inhaler devices might influence the effectiveness of inhalation therapy. We aimed to model and compare the deposition of acting agents of an open and a fixed dose combination (FDC) triple therapy and examine their repeatability.

Methods

We recruited control subjects (Controls, n = 17) and patients with stable COPD (S-COPD, n = 13) and those during an acute exacerbation (AE-COPD, n = 12). Standard spirometry was followed by through-device inhalation maneuvers using a pressurized metered dose inhaler (pMDI) and a soft mist inhaler (SMI) to calculate deposition of fixed dose and open triple combination therapies by numerical modeling. Through-device inspiratory vital capacity (IVC_d) and peak inspiratory flow (PIF_d), as well as inhalation time (t_in) and breath hold time (tbh) were used to calculate pulmonary (PD) and extrathoracic deposition (ETD) values. Deposition was calculated from two different inhalation maneuvers.

Results

There was no difference in forced expiratory volume in 1 s (FEV1) between patients (S-COPD: 42 ± 5% vs. AE-COPD: 35 ± 5% predicted). Spiriva^® Respimat^® showed significantly higher PD and lower ETD values in all COPD patients and Controls compared with the two pMDIs. For Foster^® pMDI and Trimbow^® pMDI similar PD were observed in Controls, while ETD between Controls and AE-COPD patients did significantly differ. There was no difference between COPD groups regarding the repeatability of calculated deposition values. Ranking the different inhalers by differences between the two deposition values calculated from separate maneuvers, Respimat^® produced the smallest inter-measurement differences for PD.

Discussion

Our study is the first to model and compare PD using pMDIs and an SMI as triple combination in COPD. In conclusion, switching from FDC to open triple therapy in cases when adherence to devices is maintanined may contribute to better therapeutic effectiveness in individual cases using low resistance inhalers.

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.

Pollen-Inspired Shell-Core Aerosol Particles Capable of Brownian Motion for Pulmonary Vascularization

Nebulization is the most widely used respiratory delivery technique with non-invasive properties. However, nebulized drugs often fail to function due to the excretion and immune clearance of the respiratory system. In this work, inspired by pollen in nature, novel shell-core aerosol particles (APs) capable of Brownian motion are constructed for respiratory delivery. Drugs-loaded poly(lactic-co-glycolic acid) nanoparticles are prepared by emulsification to form the inner core, and the membranes of macrophages are extracted to form the outer shell. The optimized size and the shell-core structure endow APs with Brownian motion and atomization stability, thus enabling the APs to reach the bronchi and alveoli deeply for effective deposition. Camouflaging the macrophage membranes equips the APs with immune evasion. In vitro experiments prove that deferoxamine (DFO)-loaded APs (DFO@APs) can promote the angiogenesis of human umbilical vein endothelial cells. A hyperoxia-induced bronchopulmonary dysplasia (BPD) model is constructed to validate the efficiency of DFO@APs. In BPD mice, DFO@APs can release DFO in the alveolar interstitium, thus promoting the reconstruction of microvasculature, ultimately inducing lung development for treating BPD. In conclusion, this study develops "pollen"-inspired shell-core aerosol particles capable of Brownian motion, which provides a novel idea and theoretical basis for respiratory administration.

A reappraisal of inspiratory capacity in chronic obstructive pulmonary disease: clinical correlates and role of long-acting muscarinic antagonists and long-acting β2 agonists

INTRODUCTION

In patients with chronic obstructive pulmonary disease (COPD), static and dynamic hyperinflation, together with expiratory flow limitation and gas exchange abnormalities, is one of the major causes of dyspnea, decreased exercise performance and ventilatory failure. An increase in functional residual capacity (FRC) is accompanied by a decrease in inspiratory capacity (IC), which is a volume readily available, repeatable, and simple to measure with any spirometer. Changes in IC and FRC after bronchodilation, contrary to changes in FEV₁, have been closely associated with improvements in dyspnea and exercise performance. We systematically searched PubMed and Embase databases for clinical trials that assessed the effects of dual bronchodilation on inspiratory capacity in patients with COPD.

AREAS COVERED

Despite their pivotal role in COPD, IC and static volumes have rarely been considered as primary outcomes in randomized clinical trials assessing the efficacy of bronchodilators. Available studies on dual bronchodilation have shown a significant and persistent positive impact on IC focusing mainly on patients with moderate-to-severe COPD, whereas dynamic hyperinflation is also present at milder disease stages.

EXPERT OPINION

This narrative review discusses the pathophysiological and clinical importance of measuring IC in patients with COPD and how IC can be modified by maximizing bronchodilation combining long-acting muscarinic antagonists and long-acting β2 agonists.

FIDEPOC: Consensus on Inspiratory Flow and Lung Deposition as Key Decision Factors in COPD Inhaled Therapy

Purpose

The pharmacological treatment of chronic obstructive pulmonary disease (COPD) is largely based on inhaled bronchodilators. Inspiratory flow and lung deposition are key parameters to be considered in inhaled therapy; however, the relationship between these two parameters, the patient specificities, and the suitability of the inhaler type for COPD management has not been fully addressed. The present study follows a Delphi Panel methodology to find expert consensus on the role of inspiratory flow and lung deposition as key decision factors in COPD inhaled therapy.

Methods

A two-round Delphi Panel, consisting of 38 statements (items) and completed by 57 Spanish pulmonologists, was carried out to measure the experts' consensus degree with each item.

Results

A high degree of consensus was reached on most of the items consulted, among these inspiratory flow or inspiratory capacity should be periodically considered when choosing an inhalation device and to ensure the suitability of the inhaler used; the outflow velocity and particle size of the different devices should be considered to ensure adequate lung deposition; an active device (pressurized metered-dose inhalers (pMDI) or soft mist inhalers (SMI)) should be used in patients with low inspiratory flow to achieve adequate lung deposition; and, the use of dry powder inhalers (DPI) should be re-evaluated in patients with severe obstruction and severe exacerbations.

Conclusion

This study shows the relevance of inspiratory flow and the degree of particle deposition in the lung in the choice of an inhalation device for COPD management, as well as the convenience of an SMI type device in cases of low inspiratory flow. Moreover, it highlights the scarcity of information on the specific features of inhalation devices in COPD guidelines.