Drug delivery to the lungs: challenges and opportunities

Formulation and clinical translation of inhalable nanomedicines for the treatment and prevention of pulmonary infectious diseases

Pulmonary infections caused by bacteria, viruses and fungi are a significant global health issue. Inhalation therapies are gaining interest as an effective approach to directly target infected lung sites and nanoparticle-based pulmonary delivery systems are increasingly investigated for this purpose. In this review, we provide an overview of common pulmonary infectious diseases and review recent work on the application of inhalable nanoparticle-based formulations for pulmonary infectious diseases, the formulation strategies, and the current research for delivering inhalable nanomedicines. We also evaluate the current clinical development status, market landscape, and discuss challenges that impede clinical translation and propose solutions to overcome these obstacles, highlighting promising opportunities for future advancements in the field. Despite advancements made and products reaching the market, notable gap persists in translational research, with challenges in achieving the target product profile, availability of appropriate in vivo disease models, scale-up, and market related questions, likely hindering research translation to the clinic.

Elucidating mixing process effects on pulmonary delivery efficiency of dry powder inhalers: A dual-dimensional macroscopic and microscopic perspective

Dry powder inhalers (DPIs) have been widely recommended in lung diseases on account of direct pulmonary delivery, desired drug stability, and satisfactory patient compliance. More than 90% of DPIs products consist of micronized drugs mixed with larger carrier particles for required dose delivery uniformity and desired pulmonary delivery efficiency. In formulation development, researchers often focus on the influence of mixing process on the macroscopic quantitative results of pulmonary drug delivery efficiency. However, the critical influence and underlying modulatory mechanisms of mixing parameters remain poorly understood, posing formidable challenges to the optimization of DPI formulations. In the present study, an internationally recognized cascade impactor method was employed to investigate the effects of mixing parameters on the ultimate pulmonary drug delivery efficiency from a macroscopic perspective. Subsequently, Confocal Microscopic Raman Spectroscopy (CMRS) was applied to innovatively investigate the material distribution and adhesive status of the mixed DPI particles. Meanwhile, the self-constructed Modular Process Analysis Platform (MPAP) was employed the detached behavior during pulmonary delivery, allowing us to explore the influence mechanisms from a microscopic perspective. Ultimately, correlations were established between the mixing parameters and the drug adhesive status, pulmonary drug delivery process and efficiency. This study was expected to provide novelty pioneering paradigms and dual-dimensional perspective for the direction development and optimization of DPIs.

Non-viral mRNA delivery to the lungs

The rapid advancement of mRNA therapeutics, exemplified by COVID-19 vaccines, underscores the transformative potential of non-viral delivery systems. However, achieving efficient and targeted mRNA delivery to the lungs remains a critical challenge due to biological barriers such as pulmonary mucus, nanoparticle instability, and off-target accumulation particularly in the liver. Addressing these challenges is crucial for advancing treatments for respiratory diseases, including cystic fibrosis, primary ciliary dyskinesia, and lung cancers. This review highlights emerging strategies to enhance lung-targeted mRNA delivery, focusing on lipid nanoparticles, polymeric nanoparticles, lipid-polymer hybrids, and peptide/protein conjugates. By discussing advances in bioinspired design and nanoparticle reformulation, this review provides a roadmap for overcoming current delivery limitations and accelerating the clinical translation of lung-targeted mRNA therapies.

Dynamics of nanoparticles in a 3D breathing lung-on-a-chip

The"Breathing Lung-on-a-Chip,"a novel microfluidic device featuring a stretchable membrane, replicates the natural expansion and contraction of the human lung. It provides a more realistic in-vitro platform to study respiratory diseases, particle deposition, and drug delivery mechanisms. This device enables investigations into the effects of inhaled nanoparticles (NPs) on lung tissue and supports the development of advanced inhalation therapies. Uniform and optimal concentration delivery of NPs to cultured cells within the chip is critical, particularly as membrane stretching significantly influences particle dynamics. To address this, we developed a 3D numerical model that accurately simulates NP behavior under dynamic conditions, overcoming experimental limitations. The model, validated against experimental data, explores the effects of flow dynamics, particle size, membrane porosity, and stretching frequency/intensity on NP deposition in the air channel and transfer through the porous membrane into the medium channel. The results indicate that increased membrane stretch enhances the sedimentation rate of NPs in the air channel, thereby promoting their transfer to the medium channel, particularly in membranes with initially low porosity. Additionally, excessive stretching frequencies or intensities can introduce reverse flow and stagnation, leading to a longer residence time for NPs and altering their sedimentation patterns. These insights advance our understanding of NP transport in dynamic lung environments, paving the way for more effective applications of lung-on-a-chip technology in toxicological assessments and respiratory therapy innovations.

Advanced drug delivery systems for the management of local conditions

Localized disorders, even though originally confined to a specific body part, can progress into potentially life-threatening systemic disorders if treated inappropriately. Local treatment is often highly challenging due to poor penetration of therapeutic agents from their vehicles into the affected body site. Systemic treatment on the other hand often comes with unspecific side effects. The skin is the largest organ of the body, and conditions such as wounds and bacterial or fungal infections disrupt its natural barrier properties, important for the homeostasis of the human body. Advanced drug delivery systems for treating these conditions could greatly improve the treatment outcome and patient compliance. Other parts of the body that are of interest regarding localized treatment are, for example, the eyes along with mucosal tissues which are present in the vagina and lungs. Rather than focusing on specific diseases or parts of the body, this review provides an overview of the different drug delivery platforms that have been employed for enhanced local treatment. The following systems will be discussed: nanoparticle-based systems, such as nanocrystals, polymeric, lipidic, and inorganic nanoparticles, and nanogels; cyclodextrin inclusion complexes; and several devices like microarray patches, wound dressings, and films.

Targeted delivery of TGF-β mRNA to murine lung parenchyma using one-component ionizable amphiphilic Janus Dendrimers

Current clinical strategies for the delivery of pulmonary therapeutics to the lung are primarily targeted to the upper portions of the airways, such as treatment with nebulized instillation and inhalation. However, targeted delivery to the lower regions of the lung is necessary for the treatment of parenchymal lung injury and disease. Here, we show the development of an mRNA therapeutic for the lower lung in mice using one-component Ionizable Amphiphilic Janus Dendrimers as a delivery vehicle. We deliver an anti-inflammatory cytokine mRNA, transforming growth factor-beta, to produce transient protein expression in the lower regions of the lung. This study highlights a method for precise, effective, and safe delivery of TGF-β mRNA to the lung in mice. This delivery system offers a promising approach for targeting therapeutics to the specific tissues, a strategy necessary to fill the current clinical gap in treating parenchymal lung injury and disease.

Fundamental and Targeted Approaches in Pulmonary Arterial Hypertension Treatment

Pulmonary arterial hypertension (PAH) is a chronic and progressive disease marked by vascular remodeling, inflammation, and smooth muscle cell proliferation, with limited treatment options focused primarily on symptom management. The multifactorial nature of PAH, encompassing genetic, autoimmune, and connective tissue contributions, complicates its treatment, while irreversible vascular changes, such as fibrosis, remain unaddressed by current therapies. Fundamental research on molecular pathways and targeted delivery systems has paved the way for advanced therapeutic strategies that aim to modify disease progression rather than merely manage symptoms. Nanoparticle-based drug delivery systems, leveraging controlled release and pulmonary targeting, offer a promising avenue to overcome these challenges. Such systems enable precise localization to pulmonary vasculature, minimize systemic side effects, and support emerging approaches like gene therapy and combination treatments. Future research should focus on refining nanoparticle formulations for personalized medicine, optimizing inhalation delivery systems, and integrating multi-target approaches to achieve curative outcomes in PAH. This review explores pathophysiology of PAH, current pharmacological strategies, and innovative nanoparticle-based therapies, emphasizing their potential to transform PAH treatment and address its underlying mechanisms.

Innovative approaches to asthma treatment: harnessing nanoparticle technology

In the domain of respiratory illnesses, asthma remains a critical obstacle. The heterogeneous nature of this chronic inflammatory disease poses challenges during its treatment. Glucocorticoid-based combination drug therapy now dominates clinical treatments for asthma; however, glucocorticoid resistance, numerous adverse effects, the incidence of inadequate drug delivery, and other factors need the development of more effective therapies. In recent years, there has been extensive research on nanotechnology in medicine. It has been shown in studies that these drug delivery systems can greatly enhance targeting and bioavailability and decrease the toxicity of medication. Nanoparticle drug delivery systems offer improved therapeutic efficacy compared to conventional administration techniques. Nanotechnology enables advancements in precision medicine, offering benefits for heterogeneous conditions such as asthma. This review will examine the critical factors of asthma to consider when formulating medications, as well as the role of nanomaterials and their mechanisms of action in pulmonary medicine for asthma treatment.

Does a carboxamide moiety alter the toxicokinetics of synthetic cannabinoids? A study after pulmonary and intravenous administration of cumyl-5F-P7AICA to pigs

Synthetic cannabinoids (SCs) are consumed as an alternative to cannabis. Novel compounds are developed by minor modifications in their chemical structure, e.g. insertion of a carboxamide moiety as a linker, which can potentially lead to altered toxicokinetics (TK). Knowledge on the TK data of SCs, especially structural modified substances, is scarce. Hence, interpretation of toxicological results is challenging. Therefore, the aim of the present study was to evaluate the TK of cumyl-5F-P7AICA in a pig model, which was shown to be suitable for TK studies of SCs. A 200 µg/kg body weight dose of cumyl-5F-P7AICA was administered intravenously (n = 6) or inhalatively (n = 10) via an ultrasonic nebulizer to pigs. Blood specimens were repeatedly drawn over 6 h and the concentrations of cumyl-5F-P7AICA as well as its N-pentanoic acid (NPA) metabolite were determined using a fully validated LC-MS/MS method. Based on the concentration-time profiles, a population TK analysis yielded a three-compartment model for the TK of cumyl-5F-P7AICA, whilst a two-compartment model described the NPA best. The incorporation of transit compartments accounts for the time delay between the appearance of cumyl-5F-P7AICA and NPA in serum. Finally, the model was upscaled to humans using allometric scaling. In comparison to older SCs, a higher volume of distribution was determined for cumyl-5F-P7AICA. No further relevant differences of the TK properties were observed. Insertion of a carboxamide moiety into the chemical structure of SCs does not appear to have only minor influence on the TK.

A journey into siRNA therapeutics development: A focus on Pharmacokinetics and Pharmacodynamics

siRNA therapeutics are emerging novel modalities targeting highly specific mRNA via RNA interference mechanism. Its unique pharmacokinetics (PKs) and pharmacodynamics (PDs) are significant challenges for clinical use. Furthermore, naked siRNA is a highly soluble macromolecule with a negative charge, making plasma membrane penetration a significant hurdle. It is also vulnerable to nuclease degradation. Therefore, advanced formulation technologies, such as lipid nanoparticles and N-acetylgalactosamine conjugation, have been developed and are now used in clinical practice to enhance target organ delivery and stability. The innate complex biological mechanisms of siRNA, along with its formulation, are major determinants of the PK/PD characteristics of siRNA products. To systematically and quantitatively understand these characteristics, it is essential to develop and utilize quantitative PK/PD models for siRNA therapeutics. In this review, the effects of formulation on the PKs and PK/PD models of approved siRNA products were presented, highlighting the importance of selecting appropriate biomarkers and understanding formulation, PKs, and PDs for quantitative interpreting the relationship between plasma concentration, organ concentration, biomarkers, and efficacy.

Cannabidiol and Hydroxypropyl-β-Cyclodextrin for the Development of Deflated Spherical-Shaped Inhalable Powder

In addition to the known therapeutic indications for cannabidiol, its administration by inhalation appears to be of great interest. Indeed, there is evidence of cannabidiol's efficacy in several physiological pathways, suggesting its potential for a wide range of applications for both local and systemic pulmonary administration like cancers. Significant advances in pulmonary drug delivery have led to innovative strategies to address the challenges of increasing the respirable fraction of drugs and standardizing inhalable products. Among different devices, dry powder inhalers offer significant advantages including high stability and ease of use. Particle engineering using techniques such as spray drying is now the focus of research and is expected to improve upon, rather than completely replace, traditional carrier-based formulations. The development of carrier-free powders (without lactose-carrier) is mainly used for medicines with low active ingredient doses, which limits the technology. Previously, we demonstrated the benefits of using a cyclodextrin to obtain deflated spherical-shaped powders by spray drying. In this study the potential of this excipient with a very poorly water-soluble active molecule was investigated. Inhalable cannabidiol powders were developed by spray drying, using the solubility enhancers hydroxypropyl-beta-cyclodextrin and ethanol to optimize cannabidiol water-solubility. Electron microscopy images revealed consistent deflated spherical shapes, while particle size analysis showed low polydispersity and suitable sizes for deep lung deposition (2 µm). The selected engineered powders (without ethanol) had very high fine particle fractions (> 60%) due to their deflated surface. Finally, the powder was instantly solubilized leading to drug dissolution, which is important for therapeutic efficacy. In conclusion, this study successfully develops a cannabidiol inhalation powder by particle engineering having suitable aerosolization behavior. Due to the speed of the process and the performance of the finished product, this work opens the door for future studies. It has been shown that active molecules that are only slightly soluble in water can be formulated effectively as a powder for inhalation. Other molecules could be tested and subsequent in vivo studies conducted to demonstrate correlation with these in vitro results.

Nanomedicines for Pulmonary Drug Delivery: Overcoming Barriers in the Treatment of Respiratory Infections and Lung Cancer

The pulmonary route for drug administration has garnered a great deal of attention in therapeutics for treating respiratory disorders. It allows for the delivery of drugs directly to the lungs and, consequently, the maintenance of high concentrations at the action site and a reduction in systemic adverse effects compared to other routes, such as oral or intravenous. Nevertheless, the pulmonary administration of drugs is challenging, as the respiratory system tries to eliminate inhaled particles, being the main responsible mucociliary escalator. Nanomedicines represent a primary strategy to overcome the limitations of this route as they can be engineered to prolong pulmonary retention and avoid their clearance while reducing drug systemic distribution and, consequently, systemic adverse effects. This review analyses the use of pulmonary-administered nanomedicines to treat infectious diseases affecting the respiratory system and lung carcinoma, two pathologies that represent major health threats.

Nanotherapy therapy for acute respiratory distress syndrome: a review

Acute respiratory distress syndrome (ARDS) is a complex and life-threatening disease characterized by severe respiratory failure. The lethality of ARDS remains alarmingly high, especially with the persistent ravages of coronavirus disease 2019 (COVID-19) in recent years. ARDS is one of the major complications of neocoronavirus pneumonia and the leading cause of death in infected patients. The large-scale outbreak of COVID-19 has greatly increased the incidence and mortality of ARDS. Despite advancements in our understanding of the causes and mechanisms of ARDS, the current clinical practice is still limited to the use of supportive medications to alleviate its progression. However, there remains a pressing need for effective therapeutic drugs to combat this devastating disease. In this comprehensive review, we discuss the commonly used therapeutic drugs for ARDS, including steroids, vitamin C, targeted inhibitors, and heparin. While these medications have shown some promise in managing ARDS, there is still a significant gap in the availability of definitive treatments. Moreover, we highlight the potential of nanocarrier delivery systems, such as liposomes, lipid nanoparticles, polymer nanoparticles, and inorganic nanoparticles, as promising therapeutic approaches for ARDS in the future. These innovative delivery systems have demonstrated encouraging results in early clinical trials and offer the potential for more targeted and effective treatment options. Despite the promising early results, further clinical trials are necessary to fully assess the efficacy and safety of nanotherapies for ARDS. Additionally, more in-depth research should be conducted to focus on the continuous development of precision therapies targeting different stages of ARDS development or different triggers. This will provide more ideas and rationale for the treatment of ARDS and ultimately lead to better patient outcomes.

The pharmacokinetics and tissue distribution of curcumin following inhalation administration in rats-A comparative analysis with oral and intravenous routes

A sensitive and simple method using ultra-liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed and validated to determine the concentration of curcumin in rat plasma and tissue samples. Emodin was selected as the internal standard (IS), and biological samples were pretreated with simple one-step acetonitrile precipitation. The calibration curves exhibited linearity within the range of 1-1000 ng/ml for both rat plasma and tissue samples. The accuracy and precision of intra-day as well as inter-day determinations ranged from 99.3% to 117.3% and from 98.2% to 105.1%, respectively. This method demonstrated excellent recovery rates ranging from 76.4% to 96.4% along with minimal matrix effect ranging from 86.5% to 99.6%. The effectiveness of this method was successfully demonstrated through its application in an in vivo pharmacokinetic and tissue distribution study after single administration via inhalation (100 mg/kg), oral gavage (100 mg/kg) and intravenous injection (2.5 mg/kg) of curcumin in rats. The results revealed that inhalation significantly improved the bioavailability of curcumin, with most of the drug being deposited in the lung. These findings highlight inhalation as an effective route for targeted delivery of drugs directly into lung tissues, thus suggesting potential future applications for treating pulmonary diseases utilizing inhaled curcumin.

Alginate/chitosan-based hemostatic microspheres loaded with doxorubicin liposomes for postoperative local drug delivery in solid tumor

In clinical solid tumor treatment, intraoperative bleeding, compromised postoperative recovery, and increased non-specific toxicity from chemotherapy are always challenges. To address these limitations, we developed and well characterized novel alginate/chitosan-based hemostatic microspheres loaded with doxorubicin liposomes. The multifunctional microspheres exhibited optimal drug loading capacity and excellent drug encapsulation efficiency. Remarkably, this unique structural composition enhanced the hemostatic performance by improving their swelling and adhesion properties, surpassing those of commercial hemostatic microspheres CELOX® in both rat tail amputation and hepatic injury models. In a tumor recurrence model, SCs-lip microspheres, designed with a multi-release in situ drug delivery system, achieved sustained release of doxorubicin over an extended period, effectively reducing its toxic side effects while enhancing therapeutic efficacy. Biocompatibility experiments further validated the safety profile of this multifunctional materials. The development of this drug delivery system presents a promising opportunity to bridge the "treatment gap" between solid tumor resection surgery and chemotherapy, offering a potentially transformative approach for the application of anti-tumor drugs.

Rapid deposition analysis of inhaled aerosols in human airways

A rapid data-driven method for determining regional deposition of inhaled medication aerosols in human airways is presented, which is patient specific. Inhalation patterns, device characteristics, and aerodynamic particle size distribution of medications are considered. The method is developed using dimensional analysis and Buckingham Pi theorem, and provides total, regional, and lobar distributions of aerosol deposition. 34 dimensionless quantities are selected, of which 22 encode features of the airway trees and segmented lobes, 14 pertain to the device and the drug formulation, and 13 the inhalation profile of the subject. The dimensionless correlations are obtained using a large database of computational fluid dynamics results on patient specific airways. The intraclass correlation coefficient between the current method and its training dataset is 0.92. The difference between the predicted average lobar deposition in the six asthma patients and the in-vivo data is 1.3%. The model has the potential to offer insights into the effectiveness of personalized drug delivery in clinical settings and can aid in drug development cycles.

Enhancing peptide and PMO delivery to mouse airway epithelia by chemical conjugation with the amphiphilic peptide S10

Delivery of antisense oligonucleotides (ASOs) to airway epithelial cells is arduous due to the physiological barriers that protect the lungs and the endosomal entrapment phenomenon, which prevents ASOs from reaching their intracellular targets. Various delivery strategies involving peptide-, lipid-, and polymer-based carriers are being investigated, yet the challenge remains. S10 is a peptide-based delivery agent that enables the intracellular delivery of biomolecules such as GFP, CRISPR-associated nuclease ribonucleoprotein (RNP), base editor RNP, and a fluorescent peptide into lung cells after intranasal or intratracheal administrations to mice, ferrets, and rhesus monkeys. Herein, we demonstrate that covalently attaching S10 to a fluorescently labeled peptide or a functional splice-switching phosphorodiamidate morpholino oligomer improves their intracellular delivery to airway epithelia in mice after a single intranasal instillation. Data reveal a homogeneous delivery from the trachea to the distal region of the lungs, specifically into the cells lining the airway. Quantitative measurements further highlight that conjugation via a disulfide bond through a pegylated (PEG) linker was the most beneficial strategy compared with direct conjugation (without the PEG linker) or conjugation via a permanent thiol-maleimide bond. We believe that S10-based conjugation provides a great strategy to achieve intracellular delivery of peptides and ASOs with therapeutic properties in lungs.

A comparative study of passive drug diffusion through human skin via intercellular and sweat duct route: effect of aging

A method of drug delivery that could provide control over medicine reaching the bloodstream for systemic circulation would be of immense importance. This work presents a comparative study of the temporal and spatial variation of drugs diffusing passively through two separate routes of human skin, namely intercellular (ICR) and sweat duct route (SDR). An analysis is carried out for two age groups (young < 40 years and old > 60 years of age). Governing equations based on Fick's law for mass transfer have been solved numerically using an in-house developed code. The code has been validated thoroughly with numerical and experimental work from the literature. Each skin route is modeled into three compartments sandwiched between the donor and receiver compartments. To understand the role of diffusion and partition coefficient on drug permeation, four drugs, namely hydrocortisone, trans-cinnamic acid, caffeine, and benzoic acid, are considered. The drug diffusion rate is found greater through ICR as compared to SDR. Further, the amount of drugs diffusing through both routes increases with age. Desirable drug characteristic is inferred to be a lower value of partition coefficient and a higher value of diffusion coefficient. This study could lead to real-time assessment of drugs reaching the bloodstream and beyond.

The Role of Pulmonary Drug Delivery in Modern Therapeutics: An Overview

The pulmonary drug delivery system is a promising and evolving technology in which the prescribed medicine is breathed through the lungs, and subsequently, it enters the circulation via the alveolar epithelium. This category of pulmonary drug delivery system is an appealing and non-invasive administration method. Pulmonary drug delivery is most commonly utilized to treat airway problems by providing locally active medicines directly to their site of action. The dose required to have a pharmacological effect is reduced when medicines are delivered directly to their site of action. In addition to locally acting medications, the pulmonary route can be utilized to deliver compounds with systemic effects, such as in the case of insulin inhalation therapy for systemic absorption. Particle size, bioavailability, device compatibility, and other aspects must be addressed, including the formulation of drugs into an acceptable dosage for inhalation with sufficient stability. This formulation must also be used in conjunction with a suitable inhaler device that produces an aerosol with a particle or droplet size that assures deposition in the required targeted area of the pulmonary system. Recent advancements in pulmonary drug delivery include the development of targeted nanoparticles and inhalable biologics, which enhance drug absorption and efficacy while minimizing systemic side effects. Future directions focus on personalized medicine approaches and advanced inhalation technologies, although limitations such as variable patient adherence and the need for precise dosing continue to pose challenges.

Development of a Formulation and In Vitro Evaluation of a Pulmonary Drug Delivery System for a Novel Janus Kinase (JAK) Inhibitor, CPL409116

The pursuit of targeted therapies for cytokine-dependent diseases has led to the discovery of Janus kinase (JAK) inhibitors, a promising class of drugs. Among them, CPL409116, a selective dual JAK and rho-associated protein kinase inhibitor (ROCK), has demonstrated potential for treating conditions such as pulmonary fibrosis exacerbated by the COVID-19 pandemic. This study investigated the feasibility of delivering CPL409116 via inhalation, with the aim of minimizing the systemic adverse effects associated with oral administration. Two micronization methods, jet milling and spray drying, were assessed for CPL409116, with spray drying chosen for its ability to produce an amorphous form of the compound. Moreover, parameters such as the mixing energy, drug load, and force control agent significantly influenced the fine particle fraction (FPF), a critical parameter for pulmonary drug delivery. This study provides insights into optimizing the formulation parameters to enhance the delivery efficiency of CPL409116 to the lungs, offering potential for improved therapeutic outcomes in cytokine-dependent pulmonary diseases.

Effect of fluticasone propionate/formoterol and fluticasone furoate/vilanterol on adolescents with chronic bronchial obstruction

Background

The combination of an inhaled corticosteroid (ICS) and long-acting β-agonist (LABA) (ICS/LABA) has shown superiority in improving lung function (FEV1) compared with an ICS alone. The clinical effect of a ICS/LABA combination depends on the fine-particle fraction and the pulmonary deposition.

Objective

We sought to compare the efficacy of 2 combinations of an ICS and LABA, namely, fluticasone propionate (FP) and formoterol (FORM) (FP/FORM) and fluticasone furoate (FF) and vilanterol (VI) (FF/VI), in asthmatic adolescents with chronic bronchial obstruction.

Methods

FP/FORM (125 μg/5 μg, 2 doses twice daily via the k-haler [Mundipharma, Cambridge, UK]) and FF/VI (92 μg/22 μg, once daily via the Ellipta inhaler [GlaxoSmithKline]) were administered to adolescents aged 12 to 17 years who required regular antiasthmatic medication and had a ratio of FEV1 to forced vital capacity (FEV1/FVC) less than -1.65 SD in a 2-sequence, 16-week crossover trial. The primary efficacy end point was change in FEV1 compared with baseline. Secondary end points were FEV1/FVC ratio, maximal expiratory flow at 50% of the FVC, impulse oscillometry indices respiratory resistance at 5 Hz (R5), difference between R5 and respiratory resistance at 20 Hz (R20), area of reactance, and Asthma Control Test score.

Results

Both ICS/LABA combinations resulted in a significant improvement in FEV1 and maximal expiratory flow at 50% of the FVC z scores without any significant difference between FP/FORM and FF/VI, with 40% of patients with either treatment achieving a normal prebronchodilator FEV1/FVC z score. Neither area of reactance nor difference between R5 and R20 improved significantly with either treatment.

Conclusion

Both ICS/LABA combinations demonstrated significant improvements in FEV1z score. More than one-third of the asthmatic adolescents with prolonged bronchial obstruction achieved a normal prebronchodilator FEV1/FVC ratio.

Salvianolic acid B in fibrosis treatment: a comprehensive review

Fibrosis is a public health issue of great concern characterized by the excessive deposition of extracellular matrix, leading to the destruction of parenchymal tissue and organ dysfunction that places a heavy burden on the global healthcare system due to its high incidence, disability, and mortality. Salvianolic acid B (SalB) has positively affected various human diseases, including fibrosis. In this review, we concentrate on the anti-fibrotic effects of SalB from a molecular perspective while providing information on the safety, adverse effects, and drug interactions of SalB. Additionally, we discuss the innovative SalB formulations, which give some references for further investigation and therapeutic use of SalB's anti-fibrotic qualities. Even with the encouraging preclinical data, additional research is required before relevant clinical trials can be conducted. Therefore, we conclude with recommendations for future studies. It is hoped that this review will provide comprehensive new perspectives on future research and product development related to SalB treatment of fibrosis and promote the efficient development of this field.

Construction of the pulmonary bio-adhesive delivery system of nintedanib nanocrystalline for effective treatment of pulmonary fibrosis

Pulmonary fibrosis (PF) is a chronic, progressive, and fatal lung disease with a high mortality rate. Nintedanib, as a multi-tyrosine kinase inhibitor, is widely used as the first line drug for PF patients. However, only nintedanib oral formulations are used currently in clinic and show a low drug selectivity, significant first-pass effect and low bioavailability with 4.7%, thus limiting the clinical outcome of nintedanib. In this study, nintedanib was prepared in the form of nintedanib nanocrystalline (Nib-NC) and then encapsulated with hyaluronic acid (HA) to construct a nanocrystalline-in-adhesive delivery system Nib-NC@HA with high drug loading efficacy and pulmonary bio-adhesive properties, which could avoid the first-pass effects, increase the bioavailability and reduce the systemic side effects of nintedanib. After inhalation administration of Nib-NC@HA, due to the bio-adhesive properties of HA, Nib-NC@HA could prolong the retention time of drug in the lungs and inhibit the expression of inflammation associated factors such as IL-6, IL-1β and TNF-α in lung tissue, reduce the release of pro-fibrotic growth factor, and improve the lung function, thus showing enhanced anti-fibrotic effect than Nib-NC. The results suggested that Nib-NC@HA is an efficient and optimal targeted bio-adhesive delivery system for the lungs to treat pulmonary fibrosis.

Targeted delivery of TGF-β mRNA to lung parenchyma using one-component ionizable amphiphilic Janus Dendrimers

Current clinical strategies for the delivery of pulmonary therapeutics to the lung are primarily targeted to the upper portions of the airways. However, targeted delivery to the lower regions of the lung is necessary for the treatment of parenchymal lung injury and disease. Here, we have developed an mRNA therapeutic for the lower lung using one-component Ionizable Amphiphilic Janus Dendrimers (IAJDs) as a delivery vehicle. We deliver an anti-inflammatory cytokine mRNA, transforming growth factor-beta (TGF-β), to produce transient protein expression in the lower regions of the lung. This study highlights IAJD's potential for precise, effective, and safe delivery of TGF-β mRNA to the lung. This delivery system offers a promising approach for targeting therapeutics to the specific tissues, a strategy necessary to fill the current clinical gap in treating parenchymal lung injury and disease.

Physical characteristics of quercetin pulmospheres using combination of alginate-carrageenan: Effect of polymer concentration

Indonesia is the second country with the highest number of tuberculosis (TB) cases in the world and the first in Southeast Asia, according to WHO Global Report 2020. Quercetin has been tried as an alternative therapy and was found effective. This study aims to optimize quercetin pulmospheres using combination polymers and study its characteristics as an inhalation delivery system. Combination polymers provide the advantages of safe, mucoadhesive, and compact pulmospheres. Pulmospheres were made as formula F1, F2, and F3 (polymer ratios of 1:1, 1:2, and 1:3), respectively. Pulmospheres were made with quercetin 0.2%, alginate-carrageenan (total concentration of 1.8%), and CaCl2 0.5 M. Characterization of particle size, morphology, moisture content (MC), yield, drug loading, and entrapment efficiency (EE) were conducted. The yield range was from 83.89 to 86.30% ± 4.59%. MC range was from 4.23 to 5.12% ± 0.05%. Particle size was <3 µm (between 2.19 and 2.76 ± 0.149 µm), spherical shape and smooth surface. EE range was 60.69% ± 4.45% to 77.86% ± 1.74% and the drug loading range was 1.66-2.09% ± 0.15%. F2 formula with a polymer ratio of 1:2 was the best quercetin pulmospheres. Potential pulmospheres will then be recommended for in vitro release and in vivo study.

Nanostructure-Mediated Transport of Therapeutics through Epithelial Barriers

The ability to precisely treat human disease is facilitated by the sophisticated design of pharmacologic agents. Nanotechnology has emerged as a valuable approach to creating vehicles that can specifically target organ systems, effectively traverse epithelial barriers, and protect agents from premature degradation. In this review, we discuss the molecular basis for epithelial barrier function, focusing on tight junctions, and describe different pathways that drugs can use to cross barrier-forming tissue, including the paracellular route and transcytosis. Unique features of drug delivery applied to different organ systems are addressed: transdermal, ocular, pulmonary, and oral delivery. We also discuss how design elements of different nanoscale systems, such as composition and nanostructured architecture, can be used to specifically enhance transepithelial delivery. The ability to tailor nanoscale drug delivery vehicles to leverage epithelial barrier biology is an emerging theme in the pursuit of facilitating the efficacious delivery of pharmacologic agents.

A Review on Micro and Nanoengineering in Powder-Based Pulmonary Drug Delivery

Pulmonary delivery of drugs has emerged as a promising approach for the treatment of both lung and systemic diseases. Compared to other drug delivery routes, inhalation offers numerous advantages including high targeting, fewer side effects, and a huge surface area for drug absorption. However, the deposition of drugs in the lungs can be limited by lung defence mechanisms such as mucociliary and macrophages' clearance. Among the delivery devices, dry powder inhalers represent the optimal choice due to their stability, ease of use, and absence of propellants. In the last decades, several bottom-up techniques have emerged over traditional milling to produce inhalable powders. Among these techniques, the most employed ones are spray drying, supercritical fluid technology, spray freeze-drying, and thin film freezing. Inhalable dry powders can be constituted by micronized drugs attached to a coarse carrier (e.g., lactose) or drugs embedded into a micro- or nanoparticle. Particulate-based formulations are commonly composed of polymeric micro- and nanoparticles, liposomes, solid lipid nanoparticles, dendrimers, nanocrystals, extracellular vesicles, and inorganic nanoparticles. Moreover, engineered formulations including large porous particles, swellable microparticles, nano-in-microparticles, and effervescent nanoparticles have been developed. Particle engineering has also a crucial role in tuning the physical-chemical properties of both carrier-based and carrier-free inhalable powders. This approach can increase powder flowability, deposition, and targeting by customising particle surface features.

Nanomaterials-assisted gene editing and synthetic biology for optimizing the treatment of pulmonary diseases

The use of nanomaterials in gene editing and synthetic biology has emerged as a pivotal strategy in the pursuit of refined treatment methodologies for pulmonary disorders. This review discusses the utilization of nanomaterial-assisted gene editing tools and synthetic biology techniques to promote the development of more precise and efficient treatments for pulmonary diseases. First, we briefly outline the characterization of the respiratory system and succinctly describe the principal applications of diverse nanomaterials in lung ailment treatment. Second, we elaborate on gene-editing tools, their configurations, and assorted delivery methods, while delving into the present state of nanomaterial-facilitated gene-editing interventions for a spectrum of pulmonary diseases. Subsequently, we briefly expound on synthetic biology and its deployment in biomedicine, focusing on research advances in the diagnosis and treatment of pulmonary conditions against the backdrop of the coronavirus disease 2019 pandemic. Finally, we summarize the extant lacunae in current research and delineate prospects for advancement in this domain. This holistic approach augments the development of pioneering solutions in lung disease treatment, thereby endowing patients with more efficacious and personalized therapeutic alternatives.

Pulmonary drug delivery devices and nanosystems as potential treatment strategies for acute respiratory distress syndrome (ARDS)

Despite advances in drug delivery technologies, treating acute respiratory distress syndrome (ARDS) is challenging due to pathophysiological barriers such as lung injury, oedema fluid build-up, and lung inflammation. Active pharmaceutical ingredients (API) can be delivered directly to the lung site of action with the use of aerosol-based drug delivery devices, and this circumvents the hepatic first-pass effect and improves the bioavailability of drugs. This review discusses the various challenges and barriers for pulmonary drug delivery, current interventions for delivery, considerations for effective drug delivery, and the use of nanoparticle drug delivery carriers as potential strategies for delivering therapeutics in ARDS. Nanosystems have the added benefit of entrapping drugs, increase pulmonary drug bioavailability, and using biocompatible and biodegradable excipients that can facilitate targeted and/or controlled delivery. These systems provide an alternative to existing conventional systems. An effective way to deliver drugs for the treatment of ARDS can be by using colloidal systems that are aerosolized or inhaled. Drug distribution to the deeper pulmonary tissues is necessary due to the significant endothelial cell destruction that is prevalent in ARDS. The particle size of nanoparticles (<0.5 μm) makes them ideal candidates for treating ARDS as they can reach the alveoli. A look into the various potential benefits and limitations of nanosystems used for other lung disorders is also considered to indicate how they may be useful for the potential treatment of ARDS.

Nucleotide-Binding Oligomerization Domain 1 (NOD1) Agonists Prevent SARS-CoV-2 Infection in Human Lung Epithelial Cells through Harnessing the Innate Immune Response

The lung is prone to infections from respiratory viruses such as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). A challenge in combating these infections is the difficulty in targeting antiviral activity directly at the lung mucosal tract. Boosting the capability of the respiratory mucosa to trigger a potent immune response at the onset of infection could serve as a potential strategy for managing respiratory infections. This study focused on screening immunomodulators to enhance innate immune response in lung epithelial and immune cell models. Through testing various subfamilies and pathways of pattern recognition receptors (PRRs), the nucleotide-binding and oligomerization domain (NOD)-like receptor (NLR) family was found to selectively activate innate immunity in lung epithelial cells. Activation of NOD1 and dual NOD1/2 by the agonists TriDAP and M-TriDAP, respectively, increased the number of IL-8+ cells by engaging the NF-κB and interferon response pathways. Lung epithelial cells showed a stronger response to NOD1 and dual NOD1/2 agonists compared to control. Interestingly, a less-pronounced response to NOD1 agonists was noted in PBMCs, indicating a tissue-specific effect of NOD1 in lung epithelial cells without inducing widespread systemic activation. The specificity of the NOD agonist pathway was confirmed through gene silencing of NOD1 (siRNA) and selective NOD1 and dual NOD1/2 inhibitors in lung epithelial cells. Ultimately, activation induced by NOD1 and dual NOD1/2 agonists created an antiviral environment that hindered SARS-CoV-2 replication in vitro in lung epithelial cells.

Impact of Nebulization on the Physicochemical Properties of Polymer-Lipid Hybrid Nanoparticles for Pulmonary Drug Delivery

Nanoparticles (NPs) have shown significant potential for pulmonary administration of therapeutics for the treatment of chronic lung diseases in a localized and sustained manner. Nebulization is a suitable method of NP delivery, particularly in patients whose ability to breathe is impaired due to lung diseases. However, there are limited studies evaluating the physicochemical properties of NPs after they are passed through a nebulizer. High shear stress generated during nebulization could potentially affect the surface properties of NPs, resulting in the loss of encapsulated drugs and alteration in the release kinetics. Herein, we thoroughly examined the physicochemical properties as well as the therapeutic effectiveness of Infasurf lung surfactant (IFS)-coated PLGA NPs previously developed by us after passing through a commercial Aeroneb® vibrating-mesh nebulizer. Nebulization did not alter the size, surface charge, IFS coating and bi-phasic release pattern exhibited by the NPs. However, there was a temporary reduction in the initial release of encapsulated therapeutics in the nebulized compared to non-nebulized NPs. This underscores the importance of evaluating the drug release kinetics of NPs using the inhalation method of choice to ensure suitability for the intended medical application. The cellular uptake studies demonstrated that both nebulized and non-nebulized NPs were less readily taken up by alveolar macrophages compared to lung cancer cells, confirming the IFS coating retention. Overall, nebulization did not significantly compromise the physicochemical properties as well as therapeutic efficacy of the prepared nanotherapeutics.

Distribution and suitability of pulmonary surfactants as a vehicle for topically applied antibodies in healthy and SARS-CoV-2 infected rodent lungs

The use of natural pulmonary surfactants (PS) as a drug delivery vehicle for biologics is a more recent therapeutic modality. Herein, we tested different contents of PS regarding their physicochemical properties under stress conditions. The PS content of 12.25 mg/ml (Formulation B) showed desired properties such as an isotonic osmolality ∼300 mOsm/kg and an acceptable viscosity of 8.61 cSt, being lower than in commercially available PS solutions. Formulation B passed the specifications of surface lowering capacities of >80 % total lung capacity and physiologically desired formulation properties were independent of the antibody used in the composition. The identified formulation showed the capability of significantly increasing the oxygen saturation in ex vivo isolated perfused rat lungs, compared to a control and up to 30 min post lavage. In the in vivo setting, we showed that intratracheal administration of a human mAB with and without pulmonary surfactant led to higher amounts of delivered antibody within the alveolar tissue compared to intravenous administration. The antibody with the PS formulation remained longer in the alveolar tissues than the antibody without the PS formulation. Further, SARS-CoV-2 infected Golden Syrian hamsters showed that the intranasally applied antibody reached the site of infection in the alveoli and could be detected in the alveolar region 24 h after the last administration. With this work, we demonstrated that pulmonary surfactants can be used as a pulmonary drug delivery mechanism for antibodies and may subsequently improve the antibody efficacy by increasing the residence time at the desired site of action in the alveolar tissue.

Cheminformatics approach to identify andrographolide derivatives as dual inhibitors of methyltransferases (nsp14 and nsp16) of SARS-CoV-2

The Covid-19 pandemic outbreak has accelerated tremendous efforts to discover a therapeutic strategy that targets severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to control viral infection. Various viral proteins have been identified as potential drug targets, however, to date, no specific therapeutic cure is available against the SARS-CoV-2. To address this issue, the present work reports a systematic cheminformatic approach to identify the potent andrographolide derivatives that can target methyltransferases of SARS-CoV-2, i.e. nsp14 and nsp16 which are crucial for the replication of the virus and host immune evasion. A consensus of cheminformatics methodologies including virtual screening, molecular docking, ADMET profiling, molecular dynamics simulations, free-energy landscape analysis, molecular mechanics generalized born surface area (MM-GBSA), and density functional theory (DFT) was utilized. Our study reveals two new andrographolide derivatives (PubChem CID: 2734589 and 138968421) as natural bioactive molecules that can form stable complexes with both proteins via hydrophobic interactions, hydrogen bonds and electrostatic interactions. The toxicity analysis predicts class four toxicity for both compounds with LD50 value in the range of 500-700 mg/kg. MD simulation reveals the stable formation of the complex for both the compounds and their average trajectory values were found to be lower than the control inhibitor and protein alone. MMGBSA analysis corroborates the MD simulation result and showed the lowest energy for the compounds 2734589 and 138968421. The DFT and MEP analysis also predicts the better reactivity and stability of both the hit compounds. Overall, both andrographolide derivatives exhibit good potential as potent inhibitors for both nsp14 and nsp16 proteins, however, in-vitro and in vivo assessment would be required to prove their efficacy and safety in clinical settings. Moreover, the drug discovery strategy aiming at the dual target approach might serve as a useful model for inventing novel drug molecules for various other diseases.

Parenteral, Non-Intravenous Analgesia in Acute Traumatic Pain-A Narrative Review Based on a Systematic Literature Search

Traumatic pain is frequently encountered in emergency care and requires immediate analgesia. Unfortunately, most trauma patients report sustained pain upon arrival at and discharge from the Emergency Department. Obtaining intravenous access to administer analgesics can be time-consuming, leading to treatment delay. This review provides an overview of analgesics with both fast onset and parenteral, non-intravenous routes of administration, and also indicates areas where more research is required.

Polysaccharides screening for pulmonary mucus penetration by molecular dynamics simulation and in vitro verification

Mucus penetration is one of the physiologic barriers of inhalation and nanocarriers can effectively facilitate the permeation of drugs. The interactions between the nanocarriers and mucin are crucial for penetration across the mucus layer on the respiratory tract. In this study, we proposed a molecular dynamics (MD) simulation method for the screening of polysaccharides that acted as the surface modification materials for inhalable nano-preparations to facilitate mucus penetration. MD revealed all-atom interactions between the monomers of polysaccharides, including dextran (DEX)/hyaluronic acid (HA)/carboxymethyl chitosan (CMCS) and the human mucin protein MUC5AC (hMUC5AC). The obtained data showed that DEX formed stronger non-covalent bonds with hMUC5AC compared to HA and CMCS, which suggested that HA and CMCS had better mucus permeability than DEX. For the in vitro verification, HA/CMCS-coated liposomes and DEX/PEG-inserted liposomes were prepared. The results of mucin interactions and mucus penetration studies confirmed that HA and CMCS possessed the weakest interactions with mucin and facilitated the mucus penetration, which was in consistent with the data from MD simulation. This work may shed light on the MD simulation-based screening of surface modification materials for inhalable nano-preparations to facilitate mucus penetration.

Nanocarrier-Mediated Drug Delivery via Inhalational Route for Lung Cancer Therapy: A Systematic and Updated Review

Lung cancer is one of the most severe lethal malignancies, with approximately 1.6 million deaths every year. Lung cancer can be broadly categorised into small and non-small-cell lung cancer. The traditional chemotherapy is nonspecific, destroys healthy cells and produces systemic toxicity; targeted inhalation drug delivery in conjunction with nanoformulations has piqued interest as an approach for improving chemotherapeutic drug activity in the treatment of lung cancer. Our aim is to discuss the impact of polymer and lipid-based nanocarriers (polymeric nanoparticles, liposomes, niosomes, nanostructured lipid carriers, etc.) to treat lung cancer via the inhalational route of drug administration. This review also highlights the clinical studies, patent reports and latest investigations related to lung cancer treatment through the pulmonary route. In accordance with the PRISMA guideline, a systematic literature search was carried out for published works between 2005 and 2023. The keywords used were lung cancer, pulmonary delivery, inhalational drug delivery, liposomes in lung cancer, nanotechnology in lung cancer, etc. Several articles were searched, screened, reviewed and included. The analysis demonstrated the potential of polymer and lipid-based nanocarriers to improve the entrapment of drugs, sustained release, enhanced permeability, targeted drug delivery and retention impact in lung tissues. Patents and clinical observations further strengthen the translational potential of these carrier systems for human use in lung cancer. This systematic review demonstrated the potential of pulmonary (inhalational) drug delivery approaches based on nanocarriers for lung cancer therapy.

Adjuvant Novel Nanocarrier-Based Targeted Therapy for Lung Cancer

Lung cancer has the lowest survival rate due to its late-stage diagnosis, poor prognosis, and intra-tumoral heterogeneity. These factors decrease the effectiveness of treatment. They release chemokines and cytokines from the tumor microenvironment (TME). To improve the effectiveness of treatment, researchers emphasize personalized adjuvant therapies along with conventional ones. Targeted chemotherapeutic drug delivery systems and specific pathway-blocking agents using nanocarriers are a few of them. This study explored the nanocarrier roles and strategies to improve the treatment profile's effectiveness by striving for TME. A biofunctionalized nanocarrier stimulates biosystem interaction, cellular uptake, immune system escape, and vascular changes for penetration into the TME. Inorganic metal compounds scavenge reactive oxygen species (ROS) through their photothermal effect. Stroma, hypoxia, pH, and immunity-modulating agents conjugated or modified nanocarriers co-administered with pathway-blocking or condition-modulating agents can regulate extracellular matrix (ECM), Cancer-associated fibroblasts (CAF),Tyro3, Axl, and Mertk receptors (TAM) regulation, regulatory T-cell (Treg) inhibition, and myeloid-derived suppressor cells (MDSC) inhibition. Again, biomimetic conjugation or the surface modification of nanocarriers using ligands can enhance active targeting efficacy by bypassing the TME. A carrier system with biofunctionalized inorganic metal compounds and organic compound complex-loaded drugs is convenient for NSCLC-targeted therapy.

Opportunities and Challenges for Inhalable Nanomedicine Formulations in Respiratory Diseases: A Review

Lungs experience frequent interactions with the external environment and have an abundant supply of blood; therefore, they are susceptible to invasion by pathogenic microorganisms and tumor cells. However, the limited pharmacokinetics of conventional drugs in the lungs poses a clinical challenge. The emergence of different nano-formulations has been facilitated by advancements in nanotechnology. Inhaled nanomedicines exhibit better targeting and prolonged therapeutic effects. Although nano-formulations have great potential, they still present several unknown risks. Herein, we review the (1) physiological anatomy of the lungs and their biological barriers, (2) pharmacokinetics and toxicology of nanomaterial formulations in the lungs; (3) current nanomaterials that can be applied to the respiratory system and related design strategies, and (4) current applications of inhaled nanomaterials in treating respiratory disorders, vaccine design, and imaging detection based on the characteristics of different nanomaterials. Finally, (5) we analyze and summarize the challenges and prospects of nanomaterials for respiratory disease applications. We believe that nanomaterials, particularly inhaled nano-formulations, have excellent prospects for application in respiratory diseases. However, we emphasize that the simultaneous toxic side effects of biological nanomaterials must be considered during the application of these emerging medicines. This study aims to offer comprehensive guidelines and valuable insights for conducting research on nanomaterials in the domain of the respiratory system.

Excipients for Novel Inhaled Dosage Forms: An Overview

Pulmonary drug delivery is a form of local targeting to the lungs in patients with respiratory disorders like cystic fibrosis, pulmonary arterial hypertension (PAH), asthma, chronic pulmonary infections, and lung cancer. In addition, noninvasive pulmonary delivery also presents an attractive alternative to systemically administered therapeutics, not only for localized respiratory disorders but also for systemic absorption. Pulmonary delivery offers the advantages of a relatively low dose, low incidence of systemic side effects, and rapid onset of action for some drugs compared to other systemic administration routes. While promising, inhaled delivery of therapeutics is often complex owing to factors encompassing mechanical barriers, chemical barriers, selection of inhalation device, and limited choice of dosage form excipients. There are very few excipients that are approved by the FDA for use in developing inhaled drug products. Depending upon the dosage form, and inhalation devices such as pMDIs, DPIs, and nebulizers, different excipients can be used to provide physical and chemical stability and to deliver the dose efficiently to the lungs. This review article focuses on discussing a variety of excipients that have been used in novel inhaled dosage forms as well as inhalation devices.

Nebuliser therapy in critical care: The past, present and future

Nebulisers are devices that reduce a body of liquid into a fine aerosol suitable for inhalation. Utilising the efficiency of pulmonary drug absorption, they offer a safe and powerful modality for local and systemic drug delivery in the treatment of critical illness. In comparison to conventional jet (JN) and ultrasonic nebulisers (USN), the advent of vibrating mesh nebulisers (VMN) has significantly improved the therapeutic potential of modern devices. This review article aims to summarise the history and evolution of nebulisers from first inception through to the modern vibrating mesh technology. It provides an overview on the basic science of nebulisation and pulmonary drug delivery, and the current use of nebulised therapies in critical care.

Mapping the evolution of inhaled drug delivery research: Trends, collaborations, and emerging frontiers

Inhaled drug delivery is a unique administration route known for its ability to directly target pulmonary or brain regions, facilitating rapid onset and circumventing the hepatic first-pass effect. To characterize current global trends and provide a visual overview of the latest trends in inhaled drug delivery research, bibliometric analysis of data acquired from the Web of Science Core Collection database was performed via VOSviewer and CiteSpace. Inhaled drug delivery can not only be utilized in respiratory diseases but also has potential in other types of diseases for both fundamental and clinical applications. Overall, we provide an overview of present trends, collaborations, and newly discovered frontiers of inhaled drug delivery.

Nebulised delivery of RNA formulations to the lungs: From aerosol to cytosol

In the past decade RNA-based therapies such as small interfering RNA (siRNA) and messenger RNA (mRNA) have emerged as new and ground-breaking therapeutic agents for the treatment and prevention of many conditions from viral infection to cancer. Most clinically approved RNA therapies are parenterally administered which impacts patient compliance and adds to healthcare costs. Pulmonary administration via inhalation is a non-invasive means to deliver RNA and offers an attractive alternative to injection. Nebulisation is a particularly appealing method due to the capacity to deliver large RNA doses during tidal breathing. In this review, we discuss the unique physiological barriers presented by the lung to efficient nebulised RNA delivery and approaches adopted to circumvent this problem. Additionally, the different types of nebulisers are evaluated from the perspective of their suitability for RNA delivery. Furthermore, we discuss recent preclinical studies involving nebulisation of RNA and analysis in in vitro and in vivo settings. Several studies have also demonstrated the importance of an effective delivery vector in RNA nebulisation therefore we assess the variety of lipid, polymeric and hybrid-based delivery systems utilised to date. We also consider the outlook for nebulised RNA medicinal products and the hurdles which must be overcome for successful clinical translation. In summary, nebulised RNA delivery has demonstrated promising potential for the treatment of several lung-related conditions such as asthma, COPD and cystic fibrosis, to which the mode of delivery is of crucial importance for clinical success.

Towards More Precise Targeting of Inhaled Aerosols to Different Areas of the Respiratory System

Pharmaceutical aerosols play a key role in the treatment of lung disorders, but also systemic diseases, due to their ability to target specific areas of the respiratory system (RS). This article focuses on identifying and clarifying the influence of various factors involved in the generation of aerosol micro- and nanoparticles on their regional distribution and deposition in the RS. Attention is given to the importance of process parameters during the aerosolization of liquids or powders and the role of aerosol flow dynamics in the RS. The interaction of deposited particles with the fluid environment of the lung is also pointed out as an important step in the mass transfer of the drug to the RS surface. The analysis presented highlights the technical aspects of preparing the precursors to ensure that the properties of the aerosol are suitable for a given therapeutic target. Through an analysis of existing technical limitations, selected strategies aimed at enhancing the effectiveness of targeted aerosol delivery to the RS have been identified and presented. These strategies also include the use of smart inhaling devices and systems with built-in AI algorithms.

Targeted DPPC/DMPG surface-modified voriconazole lipid nanoparticles control invasive pulmonary aspergillosis in immunocompromised population: in-vitro and in-vivo assessment

Invasive pulmonary aspergillosis (IPA) is the most devastating Aspergillus-related lung disease. Voriconazole (VRZ) is the first-line treatment against IPA. Despite availability in oral and parenteral dosage forms, risks of systemic toxicity dictate alternative pulmonary administration. Inspired by natural lung surfactants, dipalmitoylphosphatidylcholine/dimyristoylphosphatidylglycerol (DPPC/DMPG) surface-modified lipid nanoparticles (LNPs) were scrutinized for pulmonary administration. DPPC/DMPG-VRZ-LNPs prepared using ultrasonication/thin film hydration were investigated for colloidal properties over 3-month shelf storage. They were stable with a slight change in entrapment efficiency. They provided a sustained VRZ release over 24 h, with a rapid initial release. In vitro aerosolization indicated higher percentages of VRZ deposited on stages corresponding to secondary bronchi and alveolar ducts. Moreover, intrapulmonary administration maintained high lung VRZ concentration (27 ± 1.14 µg/g) after 6 h. A preclinical study using a cyclophosphamide-induced neutropenic rat model demonstrated a 3-fold reduction in BALF-Galactomannan down to 0.515 ± 0.22 µg/L confirming DPPC/DMPG-VRZ-LNPs potential in hyphal growth inhibition. Histopathological examination of infected/nontreated lung sections exhibited dense fungal load inside alveoli and blood vessels indicating massive tissue and angio-invasiveness. Nevertheless, DPPC/DMPG-VRZ-LNPs-treated animals displayed minimal hyphae with no signs of invasiveness. The developed bioinspired nanoparticles serve as prospective bioactive nanocarrier candidates for pulmonary administration of VRZ in the management of IPA.

Phase I dose-escalation study to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of an inhaled recombinant human ACE2

Background

APN01 is a soluble recombinant human angiotensin-converting enzyme 2 (rhACE2), a key player in the renin-aldosterone-angiotensin system (RAAS). In clinical studies, APN01 was administered intravenously only, so far. The aim of this study (ClinicalTrials.gov: NCT05065645) was to evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of inhaled APN01.

Methods

This was a phase I, double-blind, placebo-controlled, dose-escalation study. Inhalation was conducted via a nebuliser over 15 min in three single ascending dose (SAD) cohorts (n=24) and two multiple ascending dose (MAD) cohorts (n=16: every 12 h for 7 days). Doses in the SAD cohort were 1.25, 2.5 and 5 mg·mL-1; doses in the MAD cohort were 2.5 and 5 mg·mL-1. Safety (including adverse events (AEs), laboratory findings and lung function results), PK and PD data were assessed.

Results

In the SAD and MAD cohorts, treatment-related AEs were slightly more frequent in the active treatment group than in the placebo group. AEs were mild to moderate, with no dose-limiting toxicities. No clinically relevant changes in lung function and laboratory results were observed. The mean maximum observed plasma concentration (Cmax) values after single and multiple doses of 5 mg·mL-1 APN01 were 1.88 and 6.61 ng·mL-1, respectively. Among the PD variables, significance was found for ACE2 and angiotensin 1-5.

Conclusions

The application of aerosolised APN01 is safe and well tolerated after single and multiple doses. By achieving a high local concentration in the lungs and low systemic bioavailability, inhaled rhACE2 may present a therapeutic option in ACE2-related diseases.

The Utilization of Plant-Material-Loaded Vesicular Drug Delivery Systems in the Management of Pulmonary Diseases

Medicinal plants have been utilized to treat a variety of conditions on account of the bioactive properties that they contain. Most bioactive constituents from plants are of limited effectiveness, due to poor solubility, limited permeability, first-pass metabolism, efflux transporters, chemical instability, and food-drug interactions However, when combined with vesicular drug delivery systems (VDDS), herbal medicines can be delivered at a predetermined rate and can exhibit site-specific action. Vesicular drug delivery systems are novel pharmaceutical formulations that make use of vesicles as a means of encapsulating and transporting drugs to various locations within the body; they are a cutting-edge method of medication delivery that combats the drawbacks of conventional drug delivery methods. Drug delivery systems offer promising strategies to overcome the bioavailability limitations of bioactive phytochemicals. By improving their solubility, protecting them from degradation, enabling targeted delivery, and facilitating controlled release, drug delivery systems can enhance the therapeutic efficacy of phytochemicals and unlock their full potential in various health conditions. This review explores and collates the application of plant-based VDDS with the potential to exhibit protective effects against lung function loss in the interest of innovative and effective treatment and management of respiratory illnesses.

Nano vs Resistant Tuberculosis: Taking the Lung Route

Tuberculosis (TB) is among the top 10 infectious diseases worldwide. It is categorized among the leading killer diseases that are the reason for the death of millions of people globally. Although a standardized treatment regimen is available, non-adherence to treatment has increased multi-drug resistance (MDR) and extensive drug-resistant (XDR) TB development. Another challenge is targeting the death of TB reservoirs in the alveoli via conventional treatment. TB Drug resistance may emerge as a futuristic restraint of TB with the scarcity of effective Anti-tubercular drugs. The paradigm change towards nano-targeted drug delivery systems is mostly due to the absence of effective therapy and increased TB infection recurrent episodes with MDR. The emerging field of nanotechnology gave an admirable opportunity to combat MDR and XDR via accurate diagnosis with effective treatment. The new strategies targeting the lung via the pulmonary route may overcome the new incidence of MDR and enhance patient compliance. Therefore, this review highlights the importance and recent research on pulmonary drug delivery with nanotechnology along with prevalence, the need for the development of nanotechnology, beneficial aspects of nanomedicine, safety concerns of nanocarriers, and clinical studies.

Drug repurposing for the treatment of COVID-19: Targeting nafamostat to the lungs by a liposomal delivery system

Despite tremendous global efforts since the beginning of the COVID-19 pandemic, still only a limited number of prophylactic and therapeutic options are available. Although vaccination is the most effective measure in preventing morbidity and mortality, there is a need for safe and effective post-infection treatment medication. In this study, we explored a pipeline of 21 potential candidates, examined in the Calu-3 cell line for their antiviral efficacy, for drug repurposing. Ralimetinib and nafamostat, clinically used drugs, have emerged as attractive candidates. Due to the inherent limitations of the selected drugs, we formulated targeted liposomes suitable for both systemic and intranasal administration. Non-targeted and targeted nafamostat liposomes (LipNaf) decorated with an Apolipoprotein B peptide (ApoB-P) as a specific lung-targeting ligand were successfully developed. The developed liposomal formulations of nafamostat were found to possess favorable physicochemical properties including nano size (119-147 nm), long-term stability of the normally rapidly degrading compound in aqueous solution, negligible leakage from the liposomes upon storage, and a neutral surface charge with low polydispersity index (PDI). Both nafamostat and ralimetinib liposomes showed good cellular uptake and lack of cytotoxicity, and non-targeted LipNaf demonstrated enhanced accumulation in the lungs following intranasal (IN) administration in non-infected mice. LipNaf retained its anti-SARS-CoV 2 activity in Calu 3 cells with only a modest decrease, exhibiting complete inhibition at concentrations >100 nM. IN, but not intraperitoneal (IP) treatment with targeted LipNaf resulted in a trend to reduced viral load in the lungs of K18-hACE2 mice compared to targeted empty Lip. Nevertheless, upon removal of outlier data, a statistically significant 1.9-fold reduction in viral load was achieved. This observation further highlights the importance of a targeted delivery into the respiratory tract. In summary, we were able to demonstrate a proof-of-concept of drug repurposing by liposomal formulations with anti-SARS-CoV-2 activity. The biodistribution and bioactivity studies with LipNaf suggest an IN or inhalation route of administration for optimal therapeutic efficacy.