Is there room for further innovation in inhaled therapy for airways disease?

Design, development, and technical considerations for dry powder inhaler devices

The dry powder inhaler (DPI) stands out as a highly patient-friendly and effective pulmonary formulation, surpassing traditional and other pulmonary dosage forms in certain disease conditions. The development of DPI products, however, presents more complexities than that of other dosage forms, particularly in device design and the integration of the drug formulation. This review focuses on the capabilities of DPI devices in pulmonary drug delivery, with a special emphasis on device design and formulation development. It also discusses into the principles of deep lung particle deposition and device engineering, and provides a current overview of the market for DPI devices. Furthermore, the review highlights the use of computational fluid dynamics (CFD) in DPI product design and discusses the regulatory environment surrounding these devices.

Designing inhaled small molecule drugs for severe respiratory diseases: an overview of the challenges and opportunities

INTRODUCTION

Inhaled drugs offer advantages for the treatment of respiratory diseases over oral drugs by delivering the drug directly to the lung, thus improving the therapeutic index. There is an unmet medical need for novel therapies for lung diseases, exacerbated by a multitude of challenges for the design of inhaled small molecule drugs.

AREAS COVERED

The authors review the challenges and opportunities for the design of inhaled drugs for respiratory diseases with a focus on new target discovery, medicinal chemistry, and pharmacokinetic, pharmacodynamic, and toxicological evaluation of drug candidates.

EXPERT OPINION

Inhaled drug discovery is facing multiple unique challenges. Novel biological targets are scarce, as is the guidance for medicinal chemistry teams to design compounds with inhalation-compatible features. It is exceedingly difficult to establish a PK/PD relationship given the complexity of pulmonary PK and the impact of physical properties of the drug substance on PK. PK, PD and toxicology studies are technically challenging and require large amounts of drug substance. Despite the current challenges, the authors foresee that the design of inhaled drugs will be facilitated in the future by our increasing understanding of pathobiology, emerging medicinal chemistry guidelines, advances in drug formulation, PBPK models, and in vitro toxicology assays.

Pulmonary Diseases in Older Patients: Understanding and Addressing the Challenges

As the global population ages, pulmonary diseases among older people have emerged as a significant and growing public health concern. The increasing incidence of these conditions has led to higher rates of morbidity and mortality among older adults. This perspective study offers a thorough overview of the prevalent pulmonary diseases affecting the elderly demographic. It delves into the challenges encountered during the diagnosis and management of these conditions in older individuals, considering factors such as comorbidities, functional limitations, and medication complexities. Furthermore, innovative strategies and personalized interventions such as precision medicine, advanced therapies, telemedicine solutions, and patient-centered support systems aimed at enhancing the care provided to older individuals grappling with pulmonary disorders are thoroughly explored. By addressing the unique needs and complexities of this vulnerable population, healthcare systems can strive towards improving outcomes and enhancing the quality of life for elderly individuals affected by pulmonary diseases.

Inhaler Adherence in COPD: A Crucial Step Towards the Correct Treatment

COPD is a typical example of chronic disease. As such, treatment adherence tends to be as low as between 30% and 50%, with specific issues in COPD due to the use of inhaled therapies. Decreased adherence in COPD is associated with worse outcomes, with increased risk for exacerbations and long-term mortality. Factors that impact adherence are multiple, some related to patient, some related to clinicians and finally some related to healthcare system. Among clinician factors, prescription of simplified treatment regimens delivered by an inhaler adapted to the patient's characteristics is crucial. Although it has been observed a huge improvement in the design and usability of inhaler devices for COPD in the last two centuries, there is still a clear gap in this field. Smart inhalers as well as simplified treatment regimens could improve adherence and therefore improve long-term outcomes in COPD.

A narrative review on the Synchrobreathe™: A novel breath-actuated pressurised metered-dose inhaler for the treatment of obstructive airway diseases

Pressurised metered-dose inhalers (pMDIs) and dry powder inhalers (DPIs), are widely used to deliver drugs for the treatment of asthma and chronic obstructive pulmonary disease (COPD). Incorrect use of inhalers is one of the main obstacles to achieving better clinical control. Indeed, with pMDIs, patients fail to synchronise actuation with inhalation due to a lack of coordination and with DPIs insufficient inspiratory effort compromises drug deposition in lungs. More than 50% of patients desire to switch their pMDIs and DPIs for a better device. This led to the development of pressurised breath-actuated inhalers (BAIs) with the aim of combining the beneficial features of pMDIs and DPIs and mitigating their problems. BAIs, e.g., Synchrobreathe™, are designed such that they are activated by a low inhalation effort and mechanically actuate the dose in synchrony to inspiration, thereby resolving the need to coordinate actuation with inspiration. BAIs have advantages, including ease of use, high lung deposition of medication, and greater patient preference. We discussed the design features, operating procedure, and clinical evidence of the Synchrobreathe™ device (Cipla Ltd, India), a BAI available with a wide range of drug combinations. Studies have shown that a higher number of patients (68.19%) used the Synchrobreathe™ without any error than the pMDI (56.21%), and that the vast majority of them (92%) found it easy to understand and use. The Synchrobreathe™ is an innovative, easy-to-use inhaler that may overcome many limitations associated with pMDIs and DPIs, thus potentially improving management of obstructive airway diseases and patients' quality of life.

COPD Patients' Behaviour When Involved in the Choice of Inhaler Device

BACKGROUND

Inhaler therapy plays a crucial role in controlling respiratory symptoms in patients with chronic obstructive pulmonary disease (COPD). Incorrect or partially correct use of inhaler devices causes many chronic obstructive pulmonary disease (COPD) patients to continue to have respiratory symptoms due to poor drug deposition in the airways as a result of poor inhaler technique, leading to increased healthcare costs due to exacerbations and multiple emergency room presentations. Choosing the right inhaler device for each individual patient is a bigger challenge for doctors and chronic obstructive pulmonary disease (COPD) patients. The type of inhaler device and the correct inhaler technique depends on the control of symptoms in chronic obstructive pulmonary disease (COPD). Physicians treating patients with chronic obstructive pulmonary disease (COPD) play a central role in educating patients about the correct use of inhalation devices. The steps for the correct use of inhalation devices should be taught to patients by doctors in the presence of the family so that if the patient has difficulties handling the device correctly, the family can support them.

METHODS

Our analysis included 200 subjects divided into two groups-recommended group (RG) and chosen group (CG)-and aimed primarily to identify the behaviour of chronic obstructive pulmonary disease (COPD) patients when faced with deciding which type of inhaler device is most suitable for them. The two groups were monitored three times during the 12-month follow-up period. Monitoring required the physical presence of the patient at the investigating physician's office. The study included patients who were smokers, ex-smokers, and/or with significant exposure to occupational pollutants, aged over 40 years diagnosed with chronic obstructive pulmonary disease (COPD), risk group B and C according to the GOLD guideline staging, and on inhaled ICS+LABA treatment, although they had an indication for LAMA+LABA dual bronchodilation treatment. Patients presented for consultation on their own initiative for residual respiratory symptoms under background treatment with ICS+LABA. The investigating pulmonologist who offered consultations to all scheduled patients, on the occasion of the consultation, also checked the inclusion and exclusion criteria. If the patient did not meet the study entry criteria, they were assessed and received the appropriate treatment, and if the study entry criteria were met, the patient signed the consent and followed the steps recommended by the investigating pulmonologist. As a result, patient entry into the study was randomised 1:1, meaning that the first patient was recommended the inhaler device by the doctor and the next patient entered into the study was left to decide for themselves which type of device was most suitable for them. In both groups, the percentage of patients who had a different choice of inhaler device from that of their doctor was statistically significant.

RESULTS

Compliance to treatment at T12 was found to be low, but compared to results previously published on compliance, in our analysis, compliance was higher and the only reasons identified as responsible for the better results were related to the selection of the target groups and the regular assessments, where, in addition to reviewing the inhaler technique, patients were encouraged to continue treatment, thus creating a strong bond between patient and doctor.

CONCLUSIONS

Our analysis revealed that empowering patients by involving them in the inhaler selection process increases adherence to inhaler treatment, reduces the number of mistakes in inhaler use of the inhaler device, and implicitly the number of exacerbations.

Salbutamol in the Management of Asthma: A Review

Asthma is a common inflammatory disease of the lungs. The prevalence of asthma is increasing worldwide, and the tendency indicates that the number of asthma sufferers will soar in the coming years for several reasons, in particular, the lifestyles we have adopted that expose us to risk factors. Salbutamol is the first selective short-acting β2-agonist (SABA) used as an alternative reliever in the treatment of asthma. Its therapeutic effect is based on its potent smooth muscle relaxant properties, which allow the inhibition of bronchial smooth muscle contraction and subsequent bronchodilation. Salbutamol can be administered orally, intravenously (IV), intramuscularly (IM), subcutaneously, or by inhalation. For this reason, the pharmacokinetic (PK) parameters-absorption, distribution, metabolism, and elimination-are highly diverse and, consequently, the efficacy and adverse effects also differ between each formulation. Here, we review the pharmacological profile of different salbutamol formulations, focusing on their efficacy and adverse effects for its original application, asthma.

Impact of Sex on Proper Use of Inhaler Devices in Asthma and COPD: A Systematic Review and Meta-Analysis

Despite females being more often affected by asthma than males and the prevalence of COPD rising in females, conflicting evidence exists as to whether sex may modulate the correct inhaler technique. The aim of this study was to assess the impact of sex on the proper use of inhaler devices in asthma and COPD. A pairwise meta-analysis was performed on studies enrolling adult males and females with asthma or COPD and reporting data of patients making at least one error by inhaler device type (DPI, MDI, and SMI). The data of 6,571 patients with asthma or COPD were extracted from 12 studies. A moderate quality of evidence (GRADE +++) indicated that sex may influence the correct use of inhaler device in both asthma and COPD. The critical error rate was higher in females with asthma (OR 1.31, 95%CI 1.14−1.50) and COPD (OR 1.80, 95%CI 1.22−2.67) using DPI vs. males (p < 0.01). In addition, the use of SMI in COPD was associated with a greater rate of critical errors in females vs. males (OR 5.36, 95%CI 1.48−19.32; p < 0.05). No significant difference resulted for MDI. In conclusion, choosing the right inhaler device in agreement with sex may optimize the pharmacological treatment of asthma and COPD.

Adherence and quality of life assessment in patients with asthma treatment with budesonide/formoterol via the Elpenhaler device: the COMPLETE study

Background

Asthma is a chronic inflammatory disease of the airways that causes recurring episodes of wheezing, breathlessness, chest tightness and coughing. Inhaled drugs on a daily basis are the cornerstone of asthma treatment, therefore, patient adherence is very important.

Methods

We performed a multicenter, open, non-interventional, observational, prospective study of 716 adult patients diagnosed with asthma receiving FDC (Fixed-dose combination) budesonide/formoterol via the Elpenhaler device. We assessed the adherence to treatment at 3 and 6 months (based on the MMAS-8: 8-item Morisky Medication Adherence Scale), the quality of life and change in forced expiratory volume in 1 s (FEV1) from baseline to follow-up.

Results

Approximately 80% of the patients showed medium to high adherence throughout the study. The mean (SD) MMAS-8 score at 6 months was 6.85 (1.54) and we observed a statistically significant shift of patients from the low adherence group to the high adherence group at 6 months. Moreover, after 6 months of treatment with FDC budesonide/formoterol, we observed an increase in the patients’ quality of life that as expressed by a change 2.01 (95%CI 1.93–2.10) units in Mini AQLQ (p < 0.0001) that was more pronounced in the high adherence group. The same trend was also observed in terms of spirometry (mean FEV1 2.58 L (0.85) at the end of the study, increased by 220 mL from baseline) with a higher improvement in the medium and high adherence groups.

Conclusions

Treatment with FDC of budesonide/formoterol via the Elpenhaler device was associated with improvement in asthma-related quality of life and lung function over 6 months that were more prominent in patients with higher adherence.

Trial registration: 2017-HAL-EL-74 (ClinicalTrials.gov Identifier: NCT03300076).

The Current and Future Role of Technology in Respiratory Care

Over the past few decades, technology and improvements in artificial intelligence have dramatically changed major sectors of our day-to-day lives, including the field of healthcare. E-health includes a wide range of subdomains, such as wearables, smart-inhalers, portable electronic spirometers, digital stethoscopes, and clinical decision support systems. E-health has been consistently shown to enhance the quality of care, improve adherence to therapy, and allow early detection of worsening in chronic pulmonary diseases. The present review addresses the current and potential future role of major e-health tools and approaches in respiratory medicine, with the aim of providing readers with trustful and updated evidence to increase their awareness of the topic, and to allow them to optimally benefit from the latest innovation technology. Collected literature evidence shows that the potential of technology tools in respiratory medicine mainly relies on three fundamental interactions: between clinicians, between clinician and patient, and between patient and health technology. However, it would be desirable to establish widely agreed and adopted standards for conducting trials and reporting results in this area, as well as to take into proper consideration potentially relevant pitfalls related to privacy protection and compliance with regulatory procedures.

A roadmap to pulmonary delivery strategies for the treatment of infectious lung diseases

Pulmonary drug delivery is a highly attractive topic for the treatment of infectious lung diseases. Drug delivery via the pulmonary route offers unique advantages of no first-pass effect and high bioavailability, which provides an important means to deliver therapeutics directly to lung lesions. Starting from the structural characteristics of the lungs and the biological barriers for achieving efficient delivery, we aim to review literatures in the past decade regarding the pulmonary delivery strategies used to treat infectious lung diseases. Hopefully, this review article offers new insights into the future development of therapeutic strategies against pulmonary infectious diseases from a delivery point of view.

Analysis of improved oral drug delivery with different helical stream inhalation modes

A challenging aspect of pulmonary drug delivery devices, e.g., metered dose inhalers (MDIs), is to deliver therapeutic drugs to prescribed target locations at the required dosage level. In this study, validated computer simulations of micron-drug inhalation with angled or radially positioned helical fluid-particle streams are simulated and analyzed. For a suitable swirl number significant improvements in drug delivery, especially to deeper lung regions, have been achieved. Specifically, considering realistic polydisperse particle distributions at the mouth inlet for a subject-specific upper lung airway geometry, a 10-degree angled helical stream increased the local efficacy by up to 26% in comparison to a conventional helical stream, causing an overall dosage of about 60% to the deep lung. Considering lobe-specific drug targeting scenarios, while using an off-center, i.e., radially well positioned, helical-flow mouthpiece, the local particle-deposition efficacy increased from 9% to 24% in the left lobe and from 25% to 38% in the right lobe in comparison to conventional drug-aerosol stream released from the central position. The efficacy of helical streams for pulmonary drug delivery applications has been established.

Rational Development of a Carrier-Free Dry Powder Inhalation Formulation for Respiratory Viral Infections via Quality by Design: A Drug-Drug Cocrystal of Favipiravir and Theophylline

Formulating pharmaceutical cocrystals as inhalable dosage forms represents a unique niche in effective management of respiratory infections. Favipiravir, a broad-spectrum antiviral drug with potential pharmacological activity against SARS-CoV-2, exhibits a low aqueous solubility. An ultra-high oral dose is essential, causing low patient compliance. This study reports a Quality-by-Design (QbD)-guided development of a carrier-free inhalable dry powder formulation containing a 1:1 favipiravir-theophylline (FAV-THP) cocrystal via spray drying, which may provide an alternative treatment strategy for individuals with concomitant influenza infections and chronic obstructive pulmonary disease/asthma. The cocrystal formation was confirmed by single crystal X-ray diffraction, powder X-ray diffraction, and the construction of a temperature-composition phase diagram. A three-factor, two-level, full factorial design was employed to produce the optimized formulation and study the impact of critical processing parameters on the resulting median mass aerodynamic diameter (MMAD), fine particle fraction (FPF), and crystallinity of the spray-dried FAV-THP cocrystal. In general, a lower solute concentration and feed pump rate resulted in a smaller MMAD with a higher FPF. The optimized formulation (F1) demonstrated an MMAD of 2.93 μm and an FPF of 79.3%, suitable for deep lung delivery with no in vitro cytotoxicity observed in A549 cells.

Characterizing attributes of innovation of technologies for healthcare: a systematic review

OBJECTIVES

Characterizing and evaluating the holistic value of innovative healthcare technologies (e.g. treatments, services) constitutes a crucial goal to maximize limited resources. However, the characteristics of innovation have not been well identified. This review aims to describe the characteristics of healthcare innovation.

METHODS

We performed a comprehensive systematic search using PubMed, Embase, PsycINFO, and Econlit from inception to July 2022. Articles were included if they described innovation or the characteristics of innovation of the technologies in healthcare. Characteristics or definitions of innovation directly or indirectly described as innovation were extracted from the included articles. Two independent reviewers then conceptualized the identified characteristics of innovation to generate innovation attributes in healthcare.

RESULTS

In total, 103 articles were included in this review. Eight attributes describing innovation, i.e. novelty, step change, substantial benefits, an improvement over existing technologies, convenience and/or adherence, added value, acceptable cost, and uncounted benefits, were conceptualized. Most of the identified innovation attributes were based on the researchers' perspective.

CONCLUSIONS

This study conceptualized innovation attributes in healthcare based on the characteristics of healthcare innovation as defined in the literature. Further research is warranted to obtain a complete understanding of the perspectives of researchers and other stakeholders, including patients, healthcare providers, healthcare payers, and the pharmaceutical industry, on recognizing innovation in healthcare.KEY POINTSThis is the first systematic review to conceptualize attributes of healthcare innovation.We conceptualized eight attributes describing innovation, i.e. novelty, step change, substantial benefits, an improvement over existing technologies, convenience and/or adherence, added value, acceptable cost, and uncounted benefits based on the similar concept.In existing literature, patients' and caregivers' perspectives were less frequently found to describe the innovation attributes.Future research is needed to identify, measure, and value various stakeholders, including patients' and caregivers' perspectives on healthcare innovation.

The future of inhalation therapy in chronic obstructive pulmonary disease

The inhaled route is critical for the administration of drugs to treat patients suffering from COPD, but there is still an unmet need for new and innovative inhalers to address some limitations of existing products that do not make them suitable for many COPD patients. The treatment of COPD, currently limited to the use of bronchodilators, corticosteroids, and antibiotics, requires a significant expansion of the therapeutic armamentarium that is closely linked to the widening of knowledge on the pathogenesis and evolution of COPD. The great interest in the development of new drugs that may be able to interfere in the natural history of the disease is leading to the synthesis of numerous new molecules, of which however only a few have entered the stages of clinical development. On the other hand, further improvement of inhaled drug delivery could be an interesting possibility because it targets the organ of interest directly, requires significantly less drug to exert the pharmacological effect and, by lowering the amount of drug needed, reduces the cost of therapy. Unfortunately, however, the development of new inhaled drugs for use in COPD is currently too slow.

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Inhalation therapy is central when treating patients with COPD.

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There has been and still there is a substantial evolution in inhaler devices.

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New targets possibly useful for the development of new drugs have been identified.

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Only very few of new drugs are being evaluated for inhaled administration.

Improving the risk-to-benefit ratio of inhaled corticosteroids through delivery and dose: current progress and future directions

INTRODUCTION

Inhaled corticosteroids (ICS) are known to increase the risk of systemic and local adverse effects, especially with high doses and long-term use. Hence, considerable resources are invested to improve pharmacokinetic/pharmacodynamic (PK/PD) properties of ICS, effective delivery systems and novel combination therapies to enhance the risk-to-benefit ratio of ICS.

AREAS COVERED

There is an unmet need for new solutions to achieve optimal clinical outcomes with minimal dose of ICS. This paper gives an overview of novel treatment strategies regarding the safety of ICS therapy on the basis of the three most recent molecules introduced to our everyday clinical practice - ciclesonide, mometasone furoate, and fluticasone furoate. Advances in aerosol devices and new areas of inhalation therapy are also discussed.

EXPERT OPINION

Current progress in improving the risk-to-benefit ratio of ICS through dose and delivery probably established pathways for further developments. This applies both to the improvement of the PK/PD properties of ICS molecules but also includes technical aspects that lead to simplified applicability of the device with simultaneous optimal drug deposition in the lungs. Indubitably, the future of medicine lies not only in the development of new molecules but also in technology and digital revolution.

Role of new digital technologies and telemedicine in pulmonary rehabilitation : Smart devices in the treatment of chronic respiratory diseases

BACKGROUND

Asthma and chronic obstructive pulmonary diseases are conditions characterized by a variable progression. Some individuals experience longer asymptomatic periods while others acute worsening periods and/or exacerbations triggered by symptom multiplication factors. Medications are adjusted to the patients' respiratory function, self-assessment of health and emerging certain physical changes. A more effective treatment may be applied by real-time data registered during the patient's everyday life.

AIM AND METHODS

Introducing new modern digital technology in pulmonary rehabilitation (PR) to help tracking the patients' medication, thus we systematically reviewed the latest publications on telemedicine and pulmonary telerehabilitation.

CONCLUSION

The use of the latest digital technologies in PR is very exciting and offers great opportunities while treating patients affected by specific conditions. On the one hand, adherence to medication can be improved in patients with chronic respiratory diseases by using these new state of the art devices; on the other hand, digital devices will also be able to monitor various physiological parameters of patients during their usual everyday activities. Data can be stored on a smartphone and shared with the provider. Relying on this information, physicians will be able to tailor medications and dosage to the specific needs of individual patients. Telerehabilitation may be a sustainable solution to the growing burden of chronic respiratory disease worldwide. However, PR must keep its cornerstones, such as education and motivations, which are most successful when conducted in person. Many issues remain to be resolved in the future, e.g. cybersecurity while using smart devices since they offer unique opportunities for PR.

Oral inhalation for delivery of proteins and peptides to the lungs

Oral inhalation is the preferred route for delivery of small molecules to the lungs, because high tissue levels can be achieved shortly after application. Biologics are mainly administered by intravenous injection but inhalation might be beneficial for the treatment of lung diseases (e.g. asthma). This review discusses biological and pharmaceutical challenges for delivery of biologics and describes promising candidates. Insufficient stability of the proteins during aerosolization and the biological environment of the lung are the main obstacles for pulmonary delivery of biologics. Novel nebulizers will improve delivery by inducing less shear stress and administration as dry powder appears suitable for delivery of biologics. Other promising strategies include pegylation and development of antibody fragments, while carrier-encapsulated systems currently play no major role in pulmonary delivery of biologics for lung disease. While development of various biologics has been halted or has shown little effects, AIR DNase, alpha1-proteinase inhibitor, recombinant neuraminidase, and heparin are currently being evaluated in phase III trials. Several biologics are being tested for the treatment of coronavirus disease (COVID)-19, and it is expected that these trials will lead to improvements in pulmonary delivery of biologics.

Pharmacokinetic/pharmacodynamic approaches to drug delivery design for inhalation drugs

Introduction: Inhaled drugs are important in the treatment of many lung pathologies, but to be therapeutically effective they must reach unbound concentrations at their effect site in the lung that are adequate to interact with their pharmacodynamic properties (PD) and exert the pharmacological action over an appropriate dosing interval. Therefore, the evaluation of pharmacokinetic (PK)/PD relationship is critical to predict their possible therapeutic effect.Areas covered: We review the approaches used to assess the PK/PD relationship of the major classes of inhaled drugs that are prescribed to treat pulmonary pathologies.Expert opinion: There are still great difficulties in producing data on lung concentrations of inhaled drugs and interpreting them as to their ability to induce the desired therapeutic action. The structural complexity of the lungs, the multiplicity of processes involved simultaneously and the physical interactions between the lungs and drug make any PK/PD approach to drug delivery design for inhalation medications extremely challenging. New approaches/methods are increasing our understanding about what happens to inhaled drugs, but they are still not ready for regulatory purposes. Therefore, we must still rely on plasma concentrations based on the axiom that they reflect both the extent and the pattern of deposition within the lungs.

Delivery and adherence with inhaled therapy in asthma

The benefits of inhaled medication for the treatment of respiratory diseases are immense. Inhalers are unquestionably the most important medical devices for the treatment of asthma and in Europe today there are more than 230 different device and drug combinations of inhaled therapies many of which are available for the treatment of asthma. They are designed to alleviate the symptoms of asthma by controlling inflammation and minimising exacerbations and are intended to be simple enough to operate by all patients regardless of their age and education. However, it is still a huge challenge for patients to use their inhaler correctly and consistently and achieving asthma control continues to be an elusive goal for most patients worldwide. The reality is that despite advances in the diagnosis of asthma, the availability of comprehensive asthma management guidelines and potent asthma medications combined with efficient delivery systems, uncontrolled disease is still linked to substantial morbidity and mortality. Despite the enormous benefits of delivering topically acting medication directly to the site of disease in the lungs adherence to treatment still remains one of the biggest challenges in asthma control. This current review looks at why patients have difficulty in using their inhalers and why adherence is so poor and how this may be improved through the use of innovation in inhaler design.

Pulmonary Delivery of Biological Drugs

In the last decade, biological drugs have rapidly proliferated and have now become an important therapeutic modality. This is because of their high potency, high specificity and desirable safety profile. The majority of biological drugs are peptide- and protein-based therapeutics with poor oral bioavailability. They are normally administered by parenteral injection (with a very few exceptions). Pulmonary delivery is an attractive non-invasive alternative route of administration for local and systemic delivery of biologics with immense potential to treat various diseases, including diabetes, cystic fibrosis, respiratory viral infection and asthma, etc. The massive surface area and extensive vascularisation in the lungs enable rapid absorption and fast onset of action. Despite the benefits of pulmonary delivery, development of inhalable biological drug is a challenging task. There are various anatomical, physiological and immunological barriers that affect the therapeutic efficacy of inhaled formulations. This review assesses the characteristics of biological drugs and the barriers to pulmonary drug delivery. The main challenges in the formulation and inhalation devices are discussed, together with the possible strategies that can be applied to address these challenges. Current clinical developments in inhaled biological drugs for both local and systemic applications are also discussed to provide an insight for further research.

Peak Inspiratory Flow Measured at Different Inhaler Resistances in Patients with Asthma

BACKGROUND

Patients' peak inspiratory flow rate (PIFR) may help clinicians select an inhaler device.

OBJECTIVE

To determine the proportion of patients with asthma who could generate correct PIFRs at different inhaler resistance settings.

METHODS

During a UK asthma review service, patients' PIFR was checked at resistance settings matching their current preventer inhaler device, at R5 (high-resistance dry powder inhaler [DPI]) and at R0 (low resistance, pressurized metered dose inhaler [pMDI]). Correct PIFR ("pass") was defined for R5 as 30 to 90 L/min and for R0 as 20 to 60 L/min. A logistic regression model examined the independent predictors of incorrect PIFR ("fail") at R5 and R0. Asthma severity was assessed retrospectively from treatment level.

RESULTS

A total of 994 adults (females 64.3%) were included, of whom 90.4% currently used a preventer inhaler (71.5% pMDI). PIFR pass rates were 93.7% at R5 compared with 70.5% at R0 (P < .0001). All patients failing the R0 PIFR breathed in too fast (>60 L/min), and 20% of patients currently using pMDI failed for this reason. Independent risk factors for failing R5 were female sex, older age group, and current preventer pMDI and for failing R0 included male sex, younger age group, current preventer DPI, and mild versus severe asthma.

CONCLUSIONS

This study demonstrates that most patients with asthma can achieve adequate inspiratory flow to activate high-resistance DPIs, whereas approximately a third of patients breathe in too fast to achieve recommended inspiratory flows for correct pMDI use, including one-fifth of patients who currently use a pMDI preventer.

Nebulized Therapies in COPD: Past, Present, and the Future

Current guidelines recommend inhalation therapy as the preferred route of drug administration for treating patients with chronic obstructive pulmonary disease (COPD). Inhalation devices consist of nebulizers and handheld inhalers, such as dry-powder inhalers (DPIs), pressurized metered-dose inhalers (pMDIs), and soft mist inhalers (SMIs). Although pMDIs, DPIs and SMIs may be appropriate for most patients with COPD, certain patient populations may have challenges with these devices. Patients who have cognitive, neuromuscular, or ventilatory impairments (and receive limited assistance from caregivers), as well as those with suboptimal peak inspiratory flow may not derive the full benefit from handheld inhalers. A considerable number of patients are not capable of producing a peak inspiratory flow rate to overcome the internal resistance of DPIs. Furthermore, patients may have difficulty coordinating inhalation with device actuation, which is required for pMDIs and SMIs. However, inhalation devices such as spacers and valved holding chambers can be used with pMDIs to increase the efficiency of aerosol delivery. Nebulized treatment provides patients with COPD an alternative administration route that avoids the need for inspiratory flow, manual dexterity, or complex hand-breath coordination. The recent approval of two nebulized long-acting muscarinic antagonists has added to the extensive range of nebulized therapies in COPD. Furthermore, with the availability of quieter and more portable nebulizer devices, nebulization may be a useful treatment option in the management of certain patient populations with COPD. The aim of this narrative review was to highlight recent updates and the treatment landscape in nebulized therapy and COPD. We first discuss the pathophysiology of patients with COPD and inhalation device considerations. Second, we review the updates on recently approved and newly marketed nebulized treatments, nebulized treatments currently in development, and technological advances in nebulizer devices. Finally, we discuss the current applications of nebulized therapy in patients with COPD.

Feasibility of Aerosolized Alpha-1 Antitrypsin as a Therapeutic Option

Inhalation therapy is integral in the management of patients with chronic obstructive pulmonary disease (COPD). Specifically, intravenous augmentation therapy is available to patients with alpha-1 antitrypsin deficiency (AATD), although there is insufficient alpha-1 antitrypsin (AAT) delivery to the lungs to modify airways inflammation. In contrast, the inhaled route allows replacement therapy to reach the target site of action and with higher AAT levels. Patients certainly support the inhalation route as an alternative to intravenous injections, obviating repetitive needle insertion and allowing treatment empowerment rather than dependency on traveling to specialized units. The difficulty with inhalation has been the ability to target the formulation to the pathophysiological site of disease: the emphysematous lung parenchyma of the small alveolated airways. Recent advances have suggested nebulizers as being able to deliver an adequate dose, consistently and reproducibly, and, coupled with developments in formulation science, allowed replacement therapy to reach the epithelial lining fluid of the small airways. The bench science has been translated to the first randomized, placebo-controlled clinical trial to study the effects of nebulized AAT, which, although not meeting the primary endpoint of prolonging time to first exacerbation, showed this treatment modality was safe and achievable in a large patient cohort. Indeed, learning from this trial suggests the importance of choosing the right clinical endpoints, and recent key advances in lung physiology indices allow better assessment of the "silent zone" of small airways disease. Knowledge from other respiratory diseases will complement treating patients with AATD, where there is considerable innovation in aerosol science and inhalation medicine directed at utilizing the inhaled route. Indeed, it could be postulated that the inhaled route may not only achieve local pulmonary therapeutic benefit, but through systemic absorption and controlled pharmacokinetic profiling, the formulation may reach and treat liver disease.

Asthma management with breath-triggered inhalers: innovation through design

Background

Asthma affects the lives of hundred million people around the World. Despite notable progresses in disease management, asthma control remains largely insufficient worldwide, influencing patients’ wellbeing and quality of life. Poor patient handling of inhaling devices has been identified as a major persistent problem that significantly reduces inhaled drugs’ efficacy and is associated with poor adherence to treatment, impairing clinical results such as asthma control and increasing disease-related costs. We herein review key research and development (R&D) innovation in inhaler devices, highlighting major real-world critical errors in the handling and inhalation technique with current devices and considering potential solutions. Furthermore, we discuss current evidence regarding breath-triggered inhalers (BTI).

Main body

The two most common significant problems with inhalers are coordinating actuation and inhalation with pressurized metered-dose inhalers (pMDIs), and the need to inhale forcibly with a dry powder inhaler. BTI R&D plans were designed to overcome these problems. Its newest device k-haler® has several other important features, generating a less forceful aerosol plume than previous pMDIs, with efficient drug delivery and lung deposition, even in patients with low inspiratory flow. The local and systemic bioavailability of fluticasone propionate and formoterol (FP/FORM) administered via k-haler® has been shown to be therapeutically equivalent when administered via the previous FP/FORM pMDI. This device requires very few steps and has been considered easy to use (even at first attempt) and preferred by the patients in a randomized crossover study. In our country, FP/FORM k-haler is available without additional costs compared to FP/FORM pMDI. All devices continue to require education and regular checking of the correct inhalation technique.

Conclusion

BTI R&D can bring advantage over current available inhalers, avoiding the two most common identified critical errors in inhalation technique. K-haler® BTI is currently available, without an increased cost, and approved for adolescents and adults with asthma in whom treatment with inhaled combined therapy with long-acting beta₂-agonists and corticosteroids is indicated. Its attractive and practical design to facilitate its use has been awarded. K-haler® represents added value through innovation to fulfill actual asthma patient needs, thus with potential relevant impact in asthma management and effective control.

Biological Obstacles for Identifying In Vitro-In Vivo Correlations of Orally Inhaled Formulations

Oral inhalation of drugs is the classic therapy of obstructive lung diseases. In contrast to the oral route, the link between in vitro and in vivo findings is less well defined and predictive models and parameters for in vitro-in vivo correlations are missing. Frequently used in vitro models and problems in obtaining in vivo values to establish such models and to identify the action of formulations in vivo are discussed. It may be concluded that major obstacles to link in vitro parameters on in vivo action include lack of treatment adherence and incorrect use of inhalers by patients, variation in inhaler performance, changes by humidity, uncertainties about lung deposition, and difficulties to measure drug levels in epithelial lining fluid and tissue. Physiologically more relevant in vitro models, improvement in inhaler performance, and better techniques for in vivo measurements may help to better understand importance and interactions between individual in vitro parameters in pulmonary delivery.