Inhaled Medicines: Past, Present, and Future.

The purpose of this review is to summarize essential pharmacological, pharmaceutical, and clinical aspects in the field of orally inhaled therapies that may help scientists seeking to develop new products. After general comments on the rationale for inhaled therapies for respiratory disease, the focus is on products approved approximately over the last half a century. The organization of these sections reflects the key pharmacological categories. Products for asthma and chronic obstructive pulmonary disease include ß -2 receptor agonists, muscarinic acetylcholine receptor antagonists, glucocorticosteroids, and cromones as well as their combinations. The antiviral and antibacterial inhaled products to treat respiratory tract infections are then presented. Two "mucoactive" products-dornase α and mannitol, which are both approved for patients with cystic fibrosis-are reviewed. These are followed by sections on inhaled prostacyclins for pulmonary arterial hypertension and the challenging field of aerosol surfactant inhalation delivery, especially for prematurely born infants on ventilation support. The approved products for systemic delivery via the lungs for diseases of the central nervous system and insulin for diabetes are also discussed. New technologies for drug delivery by inhalation are analyzed, with the emphasis on those that would likely yield significant improvements over the technologies in current use or would expand the range of drugs and diseases treatable by this route of administration. SIGNIFICANCE STATEMENT: This review of the key aspects of approved orally inhaled drug products for a variety of respiratory diseases and for systemic administration should be helpful in making judicious decisions about the development of new or improved inhaled drugs. These aspects include the choices of the active ingredients, formulations, delivery systems suitable for the target patient populations, and, to some extent, meaningful safety and efficacy endpoints in clinical trials.

Changes in respiratory symptoms during 48-week treatment with ARD-3150 (inhaled liposomal ciprofloxacin) in bronchiectasis: results from the ORBIT-3 and -4 studies.

It is not known if inhaled antibiotics improve respiratory symptoms in patients with bronchiectasis. In the recent phase-3 ORBIT trials, 48 weeks' treatment with ARD-3150 (inhaled liposomal ciprofloxacin) did not significantly improve symptoms using the prespecified method of analysis comparing baseline symptoms to those after 48 weeks, when patients had been off treatment for 28 days. This method of analysis does not take account of possible improvements in symptoms while on active treatment.A post hoc analysis of two identical randomised trials of ARD-3150 (ORBIT-3 and -4) administered 28 days on and 28 days off in patients with bronchiectasis and chronic Pseudomonas aeruginosa infection. The quality-of-life bronchiectasis respiratory symptom scale (QOL-B-RSS), which has a one-week recall period, was administered every 28 days. We examined whether respiratory symptoms improved during on-treatment periods and the relationship of changes in QOL-B-RSS to changes in bacterial load using a mixed-model repeated measures approach.ARD-3150 treatment resulted in a significant improvement in respiratory symptoms during the on-treatment periods with concordant results between ORBIT-3 (estimate 1.4 points, se 0.49; p=0.004) and ORBIT-4 (estimate 1.1 point, se 0.41; p=0.006). The proportion of patients achieving a symptom improvement above the minimum clinically important difference was higher with ARD-3150 compared with placebo during on-treatment cycles (p=0.024). Changes in respiratory symptoms were correlated with changes in bacterial load in the treatment group (r=-0.89, p<0.0001). Individual estimates for decrements in the QOL-B RSS during exacerbation were -9.4 points (se 0.91) in ORBIT-3 and -10.8 points (0.74) in ORBIT-4 (both p<0.0001).Inhaled ARD-3150 resulted in significant improvements in respiratory symptoms during the on-treatment periods which were lost during off-treatment periods. These results supports the concept that reducing bacterial load can improve respiratory symptoms in patients with bronchiectasis.

Effective Treatment of Mycobacterium avium subsp. hominissuis and Mycobacterium abscessus Species Infections in Macrophages, Biofilm, and Mice by Using Liposomal Ciprofloxacin.

Nontuberculous mycobacteria (NTM) affect an increasing number of individuals worldwide. Infection with these organisms is more common in patients with chronic lung conditions, and treatment is challenging. Quinolones, such as ciprofloxacin, have been used to treat patients, but the results have not been encouraging. In this report, we evaluate novel formulations of liposome-encapsulated ciprofloxacin (liposomal ciprofloxacin) in vitro and in vivo Its efficacy against Mycobacterium avium and Mycobacterium abscessus was examined in macrophages, in biofilms, and in vivo using intranasal instillation mouse models. Liposomal ciprofloxacin was significantly more active than free ciprofloxacin against both pathogens in macrophages and biofilms. When evaluated in vivo, treatment with the liposomal ciprofloxacin formulations was associated with significant decreases in the bacterial loads in the lungs of animals infected with M. avium and M. abscessus In summary, topical delivery of liposomal ciprofloxacin in the lung at concentrations greater than those achieved in the serum can be effective in the treatment of NTM, and further evaluation is warranted.

Tuning Ciprofloxacin Release Profiles from Liposomally Encapsulated Nanocrystalline Drug.

PURPOSE: In order to attenuate the drug release rate, a single freeze-thaw step was previously shown to convert encapsulated drug into a single nanocrystal within each liposome vesicle. The goal of this study was to alter the nanocrystalline character, and thus the drug encapsulation state and release profile, by addition of surfactant prior to freeze-thaw. METHODS: A liposomal ciprofloxacin (CFI) formulation was modified by the addition of surfactant and frozen. After thawing, these formulations were characterized in terms of drug encapsulation by centrifugation-filtration, liposome structure by cryo-TEM imaging, vesicle size by dynamic light scattering, and in vitro release (IVR) performance. RESULTS: The addition of increasing levels of polysorbate 20 (0.05 to 0.4%) or Brij 30 (0.05 to 0.3%) to the CFI preparations followed by subsequent freeze-thaw, resulted in a greater proportion of vesicles without drug nanocrystals and reduced the extent of growth of the nanocrystals thus leading to modified release rates including an increase in the ratio of non-encapsulated to sustained release of drug. CONCLUSIONS: This study provides another lever to achieve the desired release rate profile from a liposomal formulation by addition of surfactant and subsequent freeze-thaw, and thus may provide a personalized approach to treating patients.

Aerosol performance and long-term stability of surfactant-associated liposomal ciprofloxacin formulations with modified encapsulation and release properties.

Previously, we showed that the encapsulation and release properties of a liposomal ciprofloxacin formulation could be modified post manufacture, by addition of surfactant in concert with osmotic swelling of the liposomes. This strategy may provide more flexibility and convenience than the alternative of manufacturing multiple batches of liposomes differing in composition to cover a wide range of release profiles. The goal of this study was to develop a surfactant-associated liposomal ciprofloxacin (CFI) formulation possessing good long-term stability which could be delivered as an inhaled aerosol. Preparations of 12.5 mg/ml CFI containing 0.4% polysorbate 20 were formulated between pH 4.7 and 5.5. These formulations, before and after mesh nebulization, and after refrigerated storage for up to 2 years, were characterized in terms of liposome structure by cryogenic transmission electron microscopy (cryo-TEM) imaging, vesicle size by dynamic light scattering, pH, drug encapsulation by centrifugation-filtration, and in vitro release (IVR) performance. Within the narrower pH range of 4.9 to 5.2, these formulations retained their physicochemical stability after 2-year refrigerated storage, were robust to mesh nebulization, and formed respirable aerosols with a volume mean diameter (VMD) of 3.7 µm and a geometric standard deviation (GSD) of 1.7. This study demonstrates that it may be possible to provide a range of release profiles by simple addition of surfactant to a liposomal formulation post manufacture, and that these formulations may retain their physicochemical properties after long-term refrigerated storage and following aerosolization by mesh nebulizer.

Inhaled, dual release liposomal ciprofloxacin in non-cystic fibrosis bronchiectasis (ORBIT-2): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: The delivery of antipseudomonal antibiotics by inhalation to Pseudomonas aeruginosa-infected subjects with non-cystic fibrosis (CF) bronchiectasis is a logical extension of treatment strategies successfully developed in CF bronchiectasis. Dual release ciprofloxacin for inhalation (DRCFI) contains liposomal ciprofloxacin, formulated to optimise airway antibiotic delivery. METHODS: Phase II, 24-week Australian/New Zealand multicentre, randomised, double-blind, placebo-controlled trial in 42 adult bronchiectasis subjects with ≥2 pulmonary exacerbations in the prior 12 months and ciprofloxacin-sensitive P aeruginosa at screening. Subjects received DRCFI or placebo in three treatment cycles of 28 days on/28 days off. The primary outcome was change in sputum P aeruginosa bacterial density to the end of treatment cycle 1 (day 28), analysed by modified intention to treat (mITT). Key secondary outcomes included safety and time to first pulmonary exacerbation-after reaching the pulmonary exacerbation endpoint subjects discontinued study drug although remained in the study. RESULTS: DRCFI resulted in a mean (SD) 4.2 (3.7) log10 CFU/g reduction in P aeruginosa bacterial density at day 28 (vs -0.08 (3.8) with placebo, p=0.002). DRCFI treatment delayed time to first pulmonary exacerbation (median 134 vs 58 days, p=0.057 mITT, p=0.046 per protocol). DRCFI was well tolerated with a similar incidence of systemic adverse events to the placebo group, but fewer pulmonary adverse events. CONCLUSIONS: Once-daily inhaled DRCFI demonstrated potent antipseudomonal microbiological efficacy in adults with non-CF bronchiectasis and ciprofloxacin-sensitive P aeruginosa. In this modest-sized phase II study, DRCFI was also well tolerated and delayed time to first pulmonary exacerbation in the per protocol population.

Liposomal nanoparticles control the uptake of ciprofloxacin across respiratory epithelia.

PURPOSE: Liposomal ciprofloxacin nanoparticles were developed to overcome the rapid clearance of antibiotics from the lungs. The formulation was evaluated for its release profile using an air interface Calu-3 cell model and further characterised for aerosol performance and antimicrobial activity. METHODS: Liposomal and free ciprofloxacin formulations were nebulised directly onto Calu-3 bronchial epithelial cells placed in an in vitro twin-stage impinger (TSI) to assess the kinetics of release. The aerosol performance of both the liposomal and free ciprofloxacin formulation was characterised using the next generation impactor. Minimum inhibitory and bactericidal concentrations (MICs and MBCs) were determined and compared between formulations to evaluate the antibacterial activity. RESULTS: The liposomal formulation successfully controlled the release of ciprofloxacin in the cell model and showed enhanced antibacterial activity against Pseudomonas aeruginosa. In addition, the formulation displayed a respirable aerosol fraction of 70.5 ± 2.03% of the emitted dose. CONCLUSION: Results indicate that the in vitro TSI air interface Calu-3 model is capable of evaluating the fate of nebulised liposomal nanoparticle formulations and support the potential for inhaled liposomal ciprofloxacin to provide a promising treatment for respiratory infections.

Nebulised Isotonic Hydroxychloroquine Aerosols for Potential Treatment of COVID-19.

The coronavirus disease 2019 (COVID-19) is an unprecedented pandemic that has severely impacted global public health and the economy. Hydroxychloroquine administered orally to COVID-19 patients was ineffective, but its antiviral and anti-inflammatory actions were observed in vitro. The lack of efficacy in vivo could be due to the inefficiency of the oral route in attaining high drug concentration in the lungs. Delivering hydroxychloroquine by inhalation may be a promising alternative for direct targeting with minimal systemic exposure. This paper reports on the characterisation of isotonic, pH-neutral hydroxychloroquine sulphate (HCQS) solutions for nebulisation for COVID-19. They can be prepared, sterilised, and nebulised for testing as an investigational new drug for treating this infection. The 20, 50, and 100 mg/mL HCQS solutions were stable for at least 15 days without refrigeration when stored in darkness. They were atomised from Aerogen Solo Ultra vibrating mesh nebulisers (1 mL of each of the three concentrations and, in addition, 1.5 mL of 100 mg/mL) to form droplets having a median volumetric diameter of 4.3-5.2 µm, with about 50-60% of the aerosol by volume < 5 µm. The aerosol droplet size decreased (from 4.95 to 4.34 µm) with increasing drug concentration (from 20 to 100 mg/mL). As the drug concentration and liquid volume increased, the nebulisation duration increased from 3 to 11 min. The emitted doses ranged from 9.1 to 75.9 mg, depending on the concentration and volume nebulised. The HCQS solutions appear suitable for preclinical and clinical studies for potential COVID-19 treatment.

Inhaled liposomal ciprofloxacin in patients with non-cystic fibrosis bronchiectasis and chronic lung infection with Pseudomonas aeruginosa (ORBIT-3 and ORBIT-4): two phase 3, randomised controlled trials.

BACKGROUND: In patients with non-cystic fibrosis bronchiectasis, lung infection with Pseudomonas aeruginosa is associated with frequent pulmonary exacerbations and admission to hospital for treatment, reduced quality of life, and increased mortality. Although inhaled antibiotics are conditionally recommended for long-term management of non-cystic fibrosis bronchiectasis with frequent exacerbations, there is no approved therapy. We investigated the safety and efficacy of inhaled liposomal ciprofloxacin (ARD-3150) in two phase 3 trials. METHODS: ORBIT-3 and ORBIT-4 were international, randomised, double-blind, placebo-controlled, phase 3 trials run concurrently in similar geographical regions. Eligible patients had non-cystic fibrosis bronchiectasis, had had at least two pulmonary exacerbations treated with antibiotics in the previous 12 months, and had a history of chronic P aeruginosa lung infection. Patients were randomly assigned (2:1) to receive either ARD-3150 or placebo. ARD-3150 (3 mL liposome encapsulated ciprofloxacin 135 mg and 3 mL free ciprofloxacin 54 mg) or 6 mL placebo (3 mL dilute empty liposomes mixed with 3 mL of saline) was self-administered once daily for six 56-day treatment cycles, for 48 weeks. The primary endpoint was time to first pulmonary exacerbation from the date of randomisation to week 48. We did primary and secondary efficacy, safety, and microbiology analyses on the full analysis population, which comprised all randomised patients who received at least one dose of study drug. ORBIT-3 and ORBIT-4 are registered with ClinicalTrials.gov, numbers NCT01515007 and NCT02104245, respectively. FINDINGS: Between March 31, 2014, and Aug 19, 2015, we screened 514 patients in ORBIT-3 and 533 patients in ORBIT-4. The full analysis populations consisted of 278 patients in ORBIT-3 (183 patients received at least one dose of ARD-3150 and 95 received placebo) and 304 patients in ORBIT-4 (206 patients received at least one dose of ARD-3150 and 98 received placebo). In ORBIT-4, the median time to first pulmonary exacerbation was 230 days in the ARD-3150 group compared with 158 days in the placebo group, a statistically significant difference of 72 days (hazard ratio [HR] 0·72 [95% CI 0·53-0·97], p=0·032). In ORBIT-3, the median time to first pulmonary exacerbation was 214 days in the ARD-3150 group and 136 days in the placebo group, a non-statistically significant difference of 78 days (HR 0·99 [95% CI 0·71-1·38], p=0·97). In a pooled analysis of data from both ORBIT-3 and ORBIT-4, the median time to first pulmonary exacerbation was 222 days in the ARD-3150 group and 157 days in the placebo group, a non-statistically significant difference of 65 days (0·82 [0·65-1·02], p=0·074). The numbers of adverse events and serious adverse events were similar in both groups in ORBIT-3 and ORBIT-4. INTERPRETATION: In patients with non-cystic fibrosis bronchiectasis and chronic P aeruginosa lung infection requiring antibiotic therapy in the preceding year, ARD-3150 led to a significantly longer median time to first pulmonary exacerbation compared with placebo in ORBIT-4, but not in ORBIT-3 or the pooled analysis. Inconsistency between the trials suggests further research is needed into the heterogeneity of non-cystic fibrosis bronchiectasis and optimal outcome measures for inhaled antibiotics. FUNDING: Aradigm Corporation.

Systemic delivery of drugs to humans via inhalation.

Unwanted systemic absorption of drugs delivered for the local treatment of respiratory disease is well documented. Methods to minimize this now exist, especially for reduction of oropharyngeal deposition. While small molecules appear to be absorbed also from the airways, it is the alveolated regions that provide a large absorptive surface. Lung has been used as a portal for systemic delivery of substances such as anesthetics, nicotine and a number of illicit drugs. Much research has lead to the solutions of the fundamental technical hurdles of practicable delivery of systemic therapeutic drugs in milligram quantities to the lung efficiently and reproducibly. Commercial manufacturing processes exist for production of delivery systems suitable for this purpose. Generally, the deposition of small molecules in the "deep lung" leads to high absorption rates, making the inhalation delivery attractive for drugs with intended rapid onset of action. Many therapeutics, especially peptides and proteins, that cannot be delivered systemically non-invasively, are absorbed with various degrees of systemic bioavailability via inhalation. The critical factor for efficient and reproducible systemic delivery is lung deposition which depends on the properties of drug particles (size, shape, density, hygroscopicity, velocity, charge) and the state of the respiratory system (including the individual's anatomy, age, sex, disease, lung volume). While concerns exist about the potential adverse reactions of the immune system to therapeutic proteins and peptides delivered to and through the lung, there is not much data on the immune response or its link to any safety issues with inhaled biologics. Desirable systemic immune effects have been demonstrated by cytokine delivery to the lung.

Development of Liposomal Ciprofloxacin to Treat Lung Infections.

Except for management of Pseudomonas aeruginosa (PA) in cystic fibrosis, there are no approved inhaled antibiotic treatments for any other diseases or for infections from other pathogenic microorganisms such as tuberculosis, non-tuberculous mycobacteria, fungal infections or potential inhaled biowarfare agents including Francisella tularensis, Yersinia pestis and Coxiella burnetii (which cause pneumonic tularemia, plague and Q fever, respectively). Delivery of an antibiotic formulation via the inhalation route has the potential to provide high concentrations at the site of infection with reduced systemic exposure to limit side effects. A liposomal formulation may improve tolerability, increase compliance by reducing the dosing frequency, and enhance penetration of biofilms and treatment of intracellular infections. Two liposomal ciprofloxacin formulations (Lipoquin(®) and Pulmaquin(®)) that are in development by Aradigm Corporation are described here.

Pharmacokinetics and acute safety of inhaled testosterone in postmenopausal women.

This was a preliminary feasibility study to assess the pharmacokinetics and acute safety of a single dose of orally inhaled testosterone via the AERx system, a novel handheld aerosol delivery system in postmenopausal women. Twelve postmenopausal women stabilized on oral estrogen therapy were treated with a single dose of testosterone (0.1, 0.2, or 0.3 mg) by inhalation. Plasma concentrations of sex steroids were measured between 1 and 360 minutes. Pulmonary and cardiovascular adverse events were monitored. Inhaled testosterone produced a dose-dependent increase in plasma total and free testosterone. At the highest dose (0.3 mg), total and free testosterone increased from baseline (mean +/- SD, 0.6 +/- 0.3 nmol/L, 2.5 +/- 1.0 pmol/L) to maximum levels of 62.6 +/- 20.4 nmol/L (total) and 168.2 +/- 50.2 pmol/L(free), occurring 1 to 2 minutes after dosing. A 2-compartment model best described the free and total testosterone pharmacokinetic profile. Dihydrotestosterone levels were higher than baseline at 60 minutes (P < .0002). Estradiol did not vary, but sex hormone binding globulin and albumin fell. There were no adverse events related to the treatment. Administration of inhaled testosterone is safe and achieves a supraphysiologic "pulse" kinetic profile of total and free testosterone with a rapid return to pretreatment levels.

Gamma scintigraphic evaluation of a miniaturized AERx pulmonary delivery system for aerosol delivery to anesthetized animals using a positive pressure ventilation system.

The purpose of this study was to characterize performance of a miniaturized AERx((R)) Pulmonary Delivery System designed for aerosol administration to large animal models. The miniaturized AERx System was developed through a systematic scaling down of the AERx System used for humans to allow for operation in certain animal models with lower inspiratory flow rates and inhaled volumes than those used for humans. We used gamma scintigraphy to characterize the in vivo particle deposition achieved with the miniaturized AERx System in two dogs. The dogs were 3-4 years old, and weighed 10.4 kg and 13.6 kg. Acepromazine was used as pre-anesthetic medication. Anesthesia was induced with 5% isoflurane. The trachea was intubated using an endotracheal tube (internal diameter 8.5 mm), and the dogs were ventilated using positive pressure during the exposure using the LRRI puff generator. An inhalation of aerosol was initiated by activation of the puff generator though the computer-controlled interface. Each dog inhaled approximately 0.8 L per puff, of which the aerosol volume comprised approximately 0.25 L, at a target flow rate of 15 L/min. The dogs were exposed to 10 AERx Strips in 10 puffs. The mass median aerodynamic diameter of the aerosolized formulation was approximately 1.25 microm with a fine particle fraction <3.5 microm of 0.976. The scintigraphic images showed uniform bilateral lung deposition following aerosol delivery with the AERx System. Total lung deposition for the two dogs was 10.7% and 18% of the loaded dose from the AERx Strip. The corresponding peripheral lung: inner lung (P/I) ratios were 0.83 and 0.75, suggestive of deposition in the deep lung. Only 0.1% to 0.2% of the loaded dose was exhaled. These results show the miniature AERx System can efficiently deliver aerosols to the deep lung of dogs. The miniaturized AERx System would be a valuable tool for conducting proof-of-concept studies as well as safety and tolerability analysis of inhaled drug candidates in large animal models.

Aerosol Performance and Stability of Liposomes Containing Ciprofloxacin Nanocrystals.

BACKGROUND: Previously we showed that the release properties of a liposomal ciprofloxacin (CFI) formulation could be attenuated by incorporation of drug nanocrystals within the vesicles. Rather than forming these drug nanocrystals during drug loading, they were created post manufacture simply by freezing and thawing the formulation. The addition of surfactant to CFI, either polysorbate 20 or Brij 30, provided an additional means to modify the release profile or incorporate an immediate-release or 'burst' component as well. The goal of this study was to develop a CFI formulation that retained its nanocrystalline morphology and attenuated release profile after delivery as an inhaled aerosol. METHODS: Preparations of 12.5 mg/mL CFI containing 90 mg/mL sucrose and 0.1% polysorbate 20 were formulated between pH 4.6 to 5.9, stored frozen, and thawed prior to use. These thawed formulations, before and after mesh nebulization, and after subsequent refrigerated storage for up to 6 weeks, were characterized in terms of liposome structure by cryogenic transmission electron microscopy (cryo-TEM) imaging, vesicle size by dynamic light scattering, pH, drug encapsulation by centrifugation-filtration, and in vitro release (IVR) performance. RESULTS: Within the narrower pH range of 4.9 to 5.3, these 12.5 mg/mL liposomal ciprofloxacin formulations containing 90 mg/mL sucrose and 0.1% polysorbate 20 retained their physicochemical stability for an additional 3 months refrigerated storage post freeze-thaw, were robust to mesh nebulization maintaining their vesicular form containing nanocrystalline drug and an associated slower release profile, and formed respirable aerosols with a mass median aerodynamic diameter (MMAD) of ∼3.9 µm and a geometric standard deviation (GSD) of ∼1.5. CONCLUSIONS: This study demonstrates that an attenuated release liposomal ciprofloxacin formulation can be created through incorporation of drug nanocrystals in response to freeze-thaw, and the formulation retains its physicochemical properties after aerosolization by mesh nebulizer.

Aerosolization of lipoplexes using AERx Pulmonary Delivery System.

The lung represents an attractive target for delivering gene therapy to achieve local and potentially systemic delivery of gene products. The objective of this study was to evaluate the feasibility of the AERx Pulmonary Delivery System for delivering nonviral gene therapy formulations to the lung. We found that "naked" DNA undergoes degradation following aerosolization through the AERx nozzle system. However, DNA formulated with a molar excess of cationic lipids (lipoplexes) showed no loss of integrity. In addition, the lipoplexes showed no significant change in particle size, zeta (zeta) potential, or degree of complexation following extrusion. The data suggest that complexation with cationic lipids had a protective effect on the formulation following extrusion. In addition, there was no significant change in the potency of the formulation as determined by a transfection study in A-549 cells in culture. We also found that DNA formulations prepared in lactose were aerosolized poorly. Significant improvements in aerosolization efficiency were seen when electrolytes such as NaCl were added to the formulation. In conclusion, the data suggest that delivery of lipoplexes using the AERx Pulmonary Delivery System may be a viable approach for pulmonary gene therapy.