Development of a Clonal and High-Yield Mammalian Cell Line for the Manufacturing of a Hyperactive Human DNase I with Extended Plasma Half-Life Using PASylation® Technology

Cumulative evidence from several pre-clinical studies suggests that restoration of plasma DNase activity in a thrombo-inflammatory state may improve clinical outcomes. Following injury, hyperactivated immune cells release large amounts of granular proteins together with DNA, which often accumulate in the surrounding environment in so-called neutrophil extracellular traps (NETs). Degradation of excess NETs by systemic DNase administration offers a promising therapeutic approach to ameliorate inflammation and dissolve intravascular clots. In order to expand the therapeutic utility of human DNase I, a variant of the enzyme was developed that has both a prolonged systemic half-life and a higher catalytic activity compared to Dornase alfa (Pulmozyme®), the recombinant form of DNase I approved for inhaled therapy of cystic fibrosis. The hyperactive enzyme was "PASylated" by genetic fusion with a strongly hydrophilic and biodegradable PAS-polypeptide to increase its hydrodynamic volume and retard kidney filtration. A stable TurboCell™ CHO-K1-based cell line was generated which is suitable for the future production of PASylated DNase I according to good manufacturing practice (GMP). Furthermore, a robust bioprocess strategy was devised and an effective downstream process was developed. The final protein product is characterized by excellent purity, favorable physicochemical properties, a 14-fold higher DNA-degrading activity than Dornase alfa and a sustained pharmacokinetic profile, with a 22-fold slower clearance in rats.

New Generation Nebulizers

Standard nebulizers are intended for general purpose use and typically are continuously operated jet or ultrasonic nebulizers. Evolutionary developments such as breath-enhanced and breath-triggered devices have improved delivery efficiency and ease of use, yet are still suitable for delivery of nebulized medications approved in this category. However, recent developments of vibrating membrane or mesh nebulizers have given rise to a significant increase in delivery efficiency requiring reformulation of former drug products or development of new formulations to match the enhanced delivery characteristics of these new devices. In addition, the electronic nature of the new devices enables tailoring to specific applications and patient groups, such as guiding or facilitating optimal breathing and improving adherence to the therapeutic regimen. Addressing these patient needs leads to new nebulization technologies being embedded in devices with fundamentally distinct functionality, modes of operation and patient interfaces. Therefore, new generation nebulizers can no longer be regarded as one category with fairly similar performance characteristics but must be clinically tested and approved as drug/device combinations together with the specific drug formulation, similar to the approval of pressurized metered-dose inhalers and dry powder inhalers. From a regulatory viewpoint, it is required that drug and device are associated with each other as combinations by clear, mutually conforming labels or, even more desirably, by distinct container-closure systems (closed system nebulizer).

Effect of atomization on the composition and structure of recombinant humanized collagen type III

Atomization is a treatment method to make inhaled liquids into aerosols and transport them to target organs in the form of fog or smoke. It has the advantages of improving the bioavailability of drugs, being painless, and non-invasive, and is now widely used in the treatment of lung and oral lesions. Aerosol inhalation as the route of administration of therapeutic proteins holds significant promise due to its ability to achieve high bioavailability in non-invasive pathways. Currently, a great number of therapeutic proteins such as alpha-1 antitrypsin and Dornase alfa are effective. Recombinant humanized collagen type III (rhCol III) as a therapeutic protein is widely used in the biomedical field, but atomization is not a common route of administration for rhCol III, presenting great potential for development. However, the structural stability of recombinant humanized collagen after atomization needs further investigation. This study demonstrated that the rhCol III subjected to atomization through compressed air had retained its original molecular weights, triple helical structures, and the ability to promote cell adhesion. In other words, the rhCol III can maintain its stability after undergoing atomization. Although more research is required to determine the efficacy and safety of the rhCol III after atomization, this study can lay the groundwork for future research.

Nebulization of PEGylated recombinant human deoxyribonuclease I using vibrating membrane nebulizers: A technical feasibility study

Recombinant human deoxyribonuclease I (rhDNase, Pulmozyme®) is the most frequently used mucolytic agent for the symptomatic treatment of cystic fibrosis (CF) lung disease. Conjugation of rhDNase to polyethylene glycol (PEG) has been shown to greatly prolong its residence time in the lungs and improve its therapeutic efficacy in mice. To present an added value over current rhDNase treatment, PEGylated rhDNase needs to be efficiently and less frequently administrated by aerosolization and possibly at higher concentrations than existing rhDNase. In this study, the effects of PEGylation on the thermodynamic stability of rhDNase was investigated using linear 20 kDa, linear 30 kDa and 2-armed 40 kDa PEGs. The suitability of PEG30-rhDNase to electrohydrodynamic atomization (electrospraying) as well as the feasibility of using two vibrating mesh nebulizers, the optimized eFlow® Technology nebulizer (eFlow) and Innospire Go, at varying protein concentrations were investigated. PEGylation was shown to destabilize rhDNase upon chemical-induced denaturation and ethanol exposure. Yet, PEG30-rhDNase was stable enough to withstand aerosolization stresses using the eFlow and Innospire Go nebulizers even at higher concentrations (5 mg of protein per ml) than conventional rhDNase formulation (1 mg/ml). High aerosol output (up to 1.5 ml per min) and excellent aerosol characteristics (up to 83% fine particle fraction) were achieved while preserving protein integrity and enzymatic activity. This work demonstrates the technical feasibility of PEG-rhDNase nebulization with advanced vibrating membrane nebulizers, encouraging further pharmaceutical and clinical developments of a long-acting PEGylated alternative to rhDNase for treating patients with CF.

Mechanisms and challenges of nanocarriers as non-viral vectors of therapeutic genes for enhanced pulmonary delivery

With the rapid development of biopharmaceuticals and the outbreak of COVID-19, the world has ushered in a frenzy to develop gene therapy. Therefore, therapeutic genes have received enormous attention. However, due to the extreme instability and low intracellular gene expression of naked genes, specific vectors are required. Viral vectors are widely used attributed to their high transfection efficiency. However, due to the safety concerns of viral vectors, nanotechnology-based non-viral vectors have attracted extensive investigation. Still, issues of low transfection efficiency and poor tissue targeting of non-viral vectors need to be addressed. Especially, pulmonary gene delivery has obvious advantages for the treatment of inherited lung diseases, lung cancer, and viral pneumonia, which can not only enhance lung targeting and but also reduce enzymatic degradation. For systemic diseases therapy, pulmonary gene delivery can enhance vaccine efficacy via inducing not only cellular, humoral immunity but also mucosal immunity. This review provides a comprehensive overview of nanocarriers as non-viral vectors of therapeutic genes for enhanced pulmonary delivery. First of all, the characteristics and therapeutic mechanism of DNA, mRNA, and siRNA are provided. Thereafter, the advantages and challenges of pulmonary gene delivery in exerting local and systemic effects are discussed. Then, the inhalation dosage forms for nanoparticle-based drug delivery systems are introduced. Moreover, a series of materials used as nanocarriers for pulmonary gene delivery are presented, and the endosomal escape mechanisms of nanocarriers based on different materials are explored. The application of various non-viral vectors for pulmonary gene delivery are summarized in detail, with the perspectives of nano-vectors for pulmonary gene delivery.

Gelatin Stabilizes Nebulized Proteins in Pulmonary Drug Delivery against COVID-19

Delivering medication to the lungs via nebulization of pharmaceuticals is a noninvasive and efficient therapy route, particularly for respiratory diseases. The recent worldwide severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic urges the development of such therapies as an effective alternative to vaccines. The main difficulties in using inhalation therapy are the development of effective medicine and methods to stabilize the biological molecules and transfer them to the lungs efficiently following nebulization. We have developed a high-affinity angiotensin-converting enzyme 2 (ACE2) receptor-binding domain (RBD-62) that can be used as a medication to inhibit infection with SARS-CoV-2 and its variants. In this study, we established a nebulization protocol for drug delivery by inhalation using two commercial vibrating mesh (VM) nebulizers (Aerogen Solo and PARI eFlow) that generate similar mist size distribution in a size range that allows efficient deposition in the small respiratory airway. In a series of experiments, we show the high activity of RBD-62, interferon-α2 (IFN-α2), and other proteins following nebulization. The addition of gelatin significantly stabilizes the proteins and enhances the fractions of active proteins after nebulization, minimizing the medication dosage. Furthermore, hamster inhalation experiments verified the feasibility of the protocol in pulmonary drug delivery. In short, the gelatin-modified RBD-62 formulation in coordination with VM nebulizer can be used as a therapy to cure SARS-CoV-2.

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 β -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.

Robustness of aerosol delivery of amikacin liposome inhalation suspension using the eFlow® Technology

The purpose of these studies was to understand the effect on product performance of batch-to-batch variability in both the amikacin liposome inhalation suspension (ALIS) formulation and its delivery device, the Lamira® nebulizer system, designed and manufactured by PARI (PARI Pharma GmbH, Munich, Germany). Three batches of ALIS spanning a range of lipid concentrations (43, 48 and 54 mg/mL) were tested with nine PARI inhalation devices that varied within the production process of the vibrating membrane with respect to hole geometry. Three hole geometry clusters were built including a geometry close to the mean geometry (median) and two geometries deviating from the mean geometry with smaller (smaller) and larger (larger) holes. The output parameters included the nebulization rate, the aerosol droplet size distribution, the liposome vesicle size post-nebulization, and the fraction of amikacin that remained encapsulated post-nebulization. Across the 27 experimental combinations of three formulation batches and nine devices, the nebulization time varied between 12 and 15 min with the fastest nebulization rate occurring with the combination of low lipid concentration and larger hole geometry (0.68 g/min) and the slowest nebulization rate occurring with the combination of high lipid concentration and the smaller hole geometry (0.59 g/min). The mean liposome vesicle size post-nebulization ranged from 269 to 296 nm across all experimental combinations which was unchanged from the control samples (276-292 nm). While all three batches contained > 99% encapsulated amikacin prior to nebulization, the nebulization process resulted in a consistent generation of ~ 35% unencapsulated amikacin (range: 33.8% to 37.6%). There was no statistically significant difference in the generated aerosol particle size distributions. The mass median aerodynamic diameters (MMAD) ranged from 4.78 µm to 4.98 µm, the geometric standard deviations (GSD) ranged from 1.61 to 1.66, and the aerosol fine particle fraction (FPF < 5 µm) ranged from 50.3 to 53.5%. The emitted dose (ED) of amikacin ranged from 473 to 523 mg (80.2 to 89.3% of loaded dose (LD)) and the fine particle dose (FPD < 5 µm) ranged from 244 to 278 mg (41.4 to 47.1% of label claim (LC)). In conclusion, while variations in the lipid concentration of the ALIS formulation and the device hole geometry had a small but significant impact on nebulization time, the critical aerosol performance parameters were maintained and remained within acceptable limits.

Developing inhaled protein therapeutics for lung diseases

Biologic therapeutics such as protein/polypeptide drugs are conventionally administered systemically via intravenous injection for the treatment of diseases including lung diseases, although this approach leads to low target site accumulation and the potential risk for systemic side effects. In comparison, topical delivery of protein drugs to the lung via inhalation is deemed to be a more effective approach for lung diseases, as proteins would directly reach the target in the lung while exhibiting poor diffusion into the systemic circulation, leading to higher lung drug retention and efficacy while minimising toxicity to other organs. This review examines the important considerations and challenges in designing an inhaled protein therapeutics for local lung delivery: the choice of inhalation device, structural changes affecting drug deposition in diseased lungs, clearance mechanisms affecting an inhaled protein drug’s lung accumulation, protein stability, and immunogenicity. Possible approaches to overcoming these issues will also be discussed.

Aerosol Delivery of Dornase Alfa Generated by Jet and Mesh Nebulizers

Recent reports on mesh nebulizers suggest the possibility of stable nebulization of various therapeutic protein drugs. In this study, the in vitro performance and drug stability of jet and mesh nebulizers were examined for dornase alfa and compared with respect to their lung delivery efficiency in BALB/c mice. We compared four nebulizers: two jet nebulizers (PARI BOY SX with red and blue nozzles), a static mesh nebulizer (NE-U150), and a vibrating mesh nebulizer (NE-SM1). The enzymatic activity of dornase alfa was assessed using a kinetic fluorometric DNase activity assay. Both jet nebulizers had large residual volumes between 24% and 27%, while the volume of the NE-SM1 nebulizer was less than 2%. Evaluation of dornase alfa aerosols produced by the four nebulizers showed no overall loss of enzymatic activity or protein content and no increase in aggregation or degradation. The amount of dornase alfa delivered to the lungs was highest for the PARI BOY SX-red jet nebulizer. This result confirmed that aerosol droplet size is an important factor in determining the efficiency of dornase alfa delivery to the lungs. Further clinical studies and analysis are required before any conclusions can be drawn regarding the clinical safety and efficacy of these nebulizers.

Protocol for TRAUMADORNASE: a prospective, randomized, multicentre, double-blinded, placebo-controlled clinical trial of aerosolized dornase alfa to reduce the incidence of moderate-to-severe hypoxaemia in ventilated trauma patients

Background

Acute respiratory distress syndrome continues to drive significant morbidity and mortality after severe trauma. The incidence of trauma-induced, moderate-to-severe hypoxaemia, according to the Berlin definition, could be as high as 45%. Its pathophysiology includes the release of damage-associated molecular patterns (DAMPs), which propagate tissue injuries by triggering neutrophil extracellular traps (NETs). NETs include a DNA backbone coated with cytoplasmic proteins, which drive pulmonary cytotoxic effects. The structure of NETs and many DAMPs includes double-stranded DNA, which prevents their neutralization by plasma. Dornase alfa is a US Food and Drug Administration-approved recombinant DNase, which cleaves extracellular DNA and may therefore break up the backbone of NETs and DAMPs. Aerosolized dornase alfa was shown to reduce trauma-induced lung injury in experimental models and to improve arterial oxygenation in ventilated patients.

Methods

TRAUMADORNASE will be an institution-led, multicentre, double-blinded, placebo-controlled randomized trial in ventilated trauma patients. The primary trial objective is to demonstrate a reduction in the incidence of moderate-to-severe hypoxaemia in severe trauma patients during the first 7 days from 45% to 30% by providing aerosolized dornase alfa as compared to placebo. The secondary objectives are to demonstrate an improvement in lung function and a reduction in morbidity and mortality. Randomization of 250 patients per treatment arm will be carried out through a secure, web-based system. Statistical analyses will include a descriptive step and an inferential step using fully Bayesian techniques. The study was approved by both the Agence Nationale de la Sécurité du Médicament et des Produits de Santé (ANSM, on 5 October 2018) and a National Institutional Review Board (CPP, on 6 November 2018). Participant recruitment began in March 2019. Results will be published in international peer-reviewed medical journals.

Discussion

If early administration of inhaled dornase alfa actually reduces the incidence of moderate-to-severe hypoxaemia in patients with severe trauma, this new therapeutic strategy may be easily implemented in many clinical trauma care settings. This treatment may facilitate ventilator weaning, reduce the burden of trauma-induced lung inflammation and facilitate recovery and rehabilitation in severe trauma patients.

Trial registration

ClinicalTrials.gov, NCT03368092. Registered on 11 December 2017.

The use of hydrophobic amino acids in protecting spray dried trehalose formulations against moisture-induced changes

Trehalose is commonly used as a protein stabilizer in spray dried protein formulations delivered via the pulmonary route. Spray dried trehalose formulations are highly hygroscopic, which makes them prone to deliquescence and recrystallization when exposed to moisture, leading to impairment in aerosolization performance. The main aim of this study was to investigate and compare the effect of hydrophobic amino acids (i.e. L-leucine and L-isoleucine) in enhancing aerosolization performance and in mitigating moisture-induced changes in spray dried trehalose formulations. Trehalose was spray dried with 20-60% w/w of amino acid (i.e. L-leucine or L-isoleucine). The spray dried formulations were stored at 25 °C/50% RH for 28 days. Solid state characterization and in vitro aerosolization performance studies were performed on the spray dried formulations before and after storage. The addition of 20-60% w/w of amino acid (i.e. L-leucine or L-isoleucine) improved the emitted fractions of spray dried trehalose formulations from a dry powder inhaler. However, ≥ 40% w/w of L-leucine/L-isoleucine was needed to prevent recrystallization of trehalose in the formulations when exposed to 25 °C/50% RH for 28 days. X-ray photoelectron spectroscopy (XPS) demonstrated that samples with 40-60% w/w L-isoleucine had more amino acid on the surfaces of the particles compared to their L-leucine counterparts. This may explain the greater ability of the L-isoleucine (40-60% w/w) samples to cope with elevated humidity compared to L-leucine samples of the same concentrations, as observed in the dynamic vapour sorption (DVS) studies. In conclusion, this study demonstrated that both L-leucine and L-isoleucine were effective in enhancing aerosolization performance and mitigating moisture-induced reduction in aerosolization performance in spray dried trehalose formulations. L-isoleucine proved to be superior to L-leucine in terms of its moisture protectant effect when incorporated at the same concentration in the formulations.

Devices for Improved Delivery of Nebulized Pharmaceutical Aerosols to the Lungs

Nebulizers have a number of advantages for the delivery of inhaled pharmaceutical aerosols, including the use of aqueous formulations and the ability to deliver process-sensitive proteins, peptides, and biological medications. A frequent disadvantage of nebulized aerosols is poor lung delivery efficiency, which wastes valuable medications, increases delivery times, and may increase side effects of the medication. A focus of previous development efforts and previous nebulizer reviews, has been an improvement of the underlying nebulization technology controlling the breakup of a liquid into droplets. However, for a given nebulization technology, a wide range of secondary devices and strategies can be implemented to significantly improve lung delivery efficiency of the aerosol. This review focuses on secondary devices and technologies that can be implemented to improve the lung delivery efficiency of nebulized aerosols and potentially target the region of drug delivery within the lungs. These secondary devices may (1) modify the aerosol size distribution, (2) synchronize aerosol delivery with inhalation, (3) reduce system depositional losses at connection points, (4) improve the patient interface, or (5) guide patient inhalation. The development of these devices and technologies is also discussed, which often includes the use of computational fluid dynamic simulations, three-dimensional printing and rapid prototype device and airway model construction, realistic in vitro experiments, and in vivo analysis. Of the devices reviewed, the implementation of streamlined components may be the most direct and lowest cost approach to enhance aerosol delivery efficiency within nonambulatory nebulizer systems. For applications involving high-dose medications or precise dose administration, the inclusion of active devices to control aerosol size, guide inhalation, and synchronize delivery with inhalation hold considerable promise.

Recombinant Human Deoxyribonuclease I

Human deoxyribonuclease I (DNase I) is an endonuclease that catalyzes the hydrolysis of extracellular DNA and is just one of the numerous types of nucleases found in nature. The enzymatic mechanism for a single turnover is reasonably well understood based on biochemical and structural studies that are consistent with divalent metal ion dependent nonspecific nicking of a phosphodiester bond in one of the strands of double stranded DNA. Recombinant human DNase I (rhDNase I, rhDNase, Pulmozyme^®, dornase alfa) has been expressed in mammalian cell culture in Chinese hamster ovary cells and developed clinically where it is aerosolized into the airways for treatment of pulmonary disease in patients with cystic fibrosis (CF). rhDNase I hydrolyzes the DNA in purulent sputum of CF patients and reduces sputum viscoelasticity. Reduction of high molecular weight DNA into smaller fragments by treatment with aerosolized rhDNase I has been proposed as the mechanism to reduce the mucus viscosity and improve mucus clearability from obstructed airways in patients. The improved clearance of the purulent mucus enhances pulmonary function and reduces recurrent exacerbations of respiratory symptoms. rhDNase I was approved for clinical use in 1993 and has been widely used as a safe and effective therapy for CF patients. The use of rhDNase I has also been investigated in other diseases where exogenous DNA has been implicated in the disease pathology.

The function and performance of aqueous aerosol devices for inhalation therapy

OBJECTIVES

In this review paper, we explore the interaction between the functioning mechanism of different nebulizers and the physicochemical properties of the formulations for several types of devices, namely jet, ultrasonic and vibrating-mesh nebulizers; colliding and extruded jets; electrohydrodynamic mechanism; surface acoustic wave microfluidic atomization; and capillary aerosol generation.

KEY FINDINGS

Nebulization is the transformation of bulk liquids into droplets. For inhalation therapy, nebulizers are widely used to aerosolize aqueous systems, such as solutions and suspensions. The interaction between the functioning mechanism of different nebulizers and the physicochemical properties of the formulations plays a significant role in the performance of aerosol generation appropriate for pulmonary delivery. Certain types of nebulizers have consistently presented temperature increase during the nebulization event. Therefore, careful consideration should be given when evaluating thermo-labile drugs, such as protein therapeutics. We also present the general approaches for characterization of nebulizer formulations.

SUMMARY

In conclusion, the interplay between the dosage form (i.e. aqueous systems) and the specific type of device for aerosol generation determines the effectiveness of drug delivery in nebulization therapies, thus requiring extensive understanding and characterization.

Protein stability in pulmonary drug delivery via nebulization

Protein inhalation is a delivery route which offers high potential for direct local lung application of proteins. Liquid formulations are usually available in early stages of biopharmaceutical development and nebulizers are the device of choice for atomization avoiding additional process steps like drying and enabling fast progression to clinical trials. While some proteins were proven to remain stable throughout aerosolization e.g. DNase, many biopharmaceuticals are more susceptible towards the stresses encountered during nebulization. The main reason for protein instability is unfolding and aggregation at the air-liquid interface, a problem which is of particular challenge in the case of ultrasound and jet nebulizers due to recirculation of much of the generated droplets. Surfactants are an important formulation component to protect the sensitive biomolecules. A second important challenge is warming of ultrasound and vibrating mesh devices, which can be overcome by overfilling, precooled solutions or cooling of the reservoir. Ultimately, formulation development has to go hand in hand with device evaluation.

Randomized trial of efficacy and safety of dornase alfa delivered by eRapid nebulizer in cystic fibrosis patients

BACKGROUND

Dornase alfa administered via jet nebulizer is indicated as a chronic respiratory medication for cystic fibrosis (CF) patients. Efficacy and safety of dornase alfa via an electronic nebulizer with vibrating membrane technology have not been formally assessed in randomized clinical trials.

METHODS

87 CF patients (≥6 years) were randomized in a crossover study to receive dornase alfa 2.5 mg/d in 2-week periods with the Pari eRapid and Pari LC Plus jet nebulizers. The primary end point was comparison of forced expiratory volume in the first second. Safety, quality of life, and treatment satisfaction/preference were also compared between devices.

RESULTS

Lung function was equivalent between nebulizers. Most domain scores from the Cystic Fibrosis Questionnaire-Revised and Treatment Satisfaction Questionnaire for Medication instruments were similar but patients strongly preferred the eRapid. Mean patient-reported administration times were shorter with the eRapid vs the LC Plus (2.7 vs 10.2 min). Adverse events were similar between devices.

CONCLUSIONS

Administration of dornase alfa via the eRapid nebulizer resulted in comparable efficacy and safety, shorter nebulization times, and higher patient preference.

Variability in Nose-to-Lung Aerosol Delivery

Nasal delivery of lung targeted pharmaceutical aerosols is ideal for drugs that need to be administered during high flow nasal cannula (HFNC) gas delivery, but based on previous studies losses and variability through both the delivery system and nasal cavity are expected to be high. The objective of this study was to assess the variability in aerosol delivery through the nose to the lungs with a nasal cannula interface for conventional and excipient enhanced growth (EEG) delivery techniques. A database of nasal cavity computed tomography (CT) scans was collected and analyzed, from which four models were selected to represent a wide range of adult anatomies, quantified based on the nasal surface area-to-volume ratio (SA/V). Computational fluid dynamics (CFD) methods were validated with existing in vitro data and used to predict aerosol delivery through a streamlined nasal cannula and the four nasal models at a steady state flow rate of 30 L/min. Aerosols considered were solid particles for EEG delivery (initial 0.9 μm and 1.5 μm aerodynamic diameters) and conventional droplets (5 μm) for a control case. Use of the EEG approach was found to reduce depositional losses in the nasal cavity by an order of magnitude and substantially reduce variability. Specifically, for aerosol deposition efficiency in the four geometries, the 95% confidence intervals (CI) for 0.9 and 5 μm aerosols were 2.3-3.1 and 15.5-66.3%, respectively. Simulations showed that the use of EEG as opposed to conventional methods improved delivered dose of aerosols through the nasopharynx, expressed as penetration fraction (PF), by approximately a factor of four. Variability of PF, expressed by the coefficient of variation (CV), was reduced by a factor of four with EEG delivery compared with the control case. Penetration fraction correlated well with SA/V for larger aerosols, but smaller aerosols showed some dependence on nasopharyngeal exit hydraulic diameter. In conclusion, results indicated that the EEG technique not only improved lung aerosol delivery, but largely eliminated variability in both nasal depositional loss and lung PF in a newly developed set of nasal airway models.

Nebulizing poractant alfa versus conventional instillation: Ultrastructural appearance and preservation of surface activity

BACKGROUND

Nebulized surfactant therapy has been proposed as an alternative method of surfactant administration. The use of a perforated vibrating membrane nebulizer provides a variety of advantages over conventional nebulizers. We investigated the molecular structure and integrity of poractant alfa pre- and post-nebulization.

METHOD

Curosurf® was nebulized using an Investigational eFlow® Nebulizer System. Non-nebulized surfactant ("NN"), recollected surfactant droplets from nebulization through an endotracheal tube ("NT") and nebulization of surfactant directly onto a surface ("ND") were investigated by transmission electron microscopy. Biophysical characteristics were assessed by the Langmuir-Wilhelmy balance and the Captive Bubble Surfactometer.

RESULTS

Volume densities of lamellar body-like forms (LBL) and multi-lamellar forms (ML) were high for "NN" and "NT" samples (38.8% vs. 47.7% for LBL and 58.2% vs. 47.8% for ML). In the "ND" sample, we found virtually no LBL's, ML's (72.6%) as well as uni-lamellar forms (16.4%) and a new structure, the "garland-like" forms (9.4%). Surface tension for "NN" and "NT" was 23.33 ± 0.29 and 25.77 ± 1.12 mN/m, respectively. Dynamic compression-expansion cycling minimum surface tensions were between 0.91 and 1.77 mN/m.

CONCLUSION

The similarity of surfactant characteristics of nebulized surfactant via a tube and the non-nebulized surfactant suggests that vibrating membrane nebulizers are suitable for surfactant nebulization. Alterations in surfactant morphology and characteristics after nebulization were transient. A new structural subtype of surfactant was identified.

Physicochemical compatibility and stability of nebulizable drug admixtures containing Dornase alfa and tobramycin

The objective of this in-vitro study was to determine whether admixtures of the inhalation solutions Pulmozyme(®) (Dornase alfa) and either Bramitob(®) or Tobi(®) (both containing Tobramycin) are physicochemically compatible and to analyze the aerodynamic parameters of these admixtures. After mixing, test solutions were stored at room temperature and under ambient light conditions over a period of 24 h. Tobramycin concentrations were determined by using a fluorescence immunoassay. Stability of dornase alfa was determined by size-exclusion high performance liquid chromatography, ultraviolet spectroscopy, sodium dodecyl sulfate polyacrylamide gel electrophoresis and tentacle strong cation-exchange chromatography. In addition, pH values and osmolality of the admixtures were measured and test solutions were visually examined for any changes up to 24 h. Aerosols of Pulmozyme(®)/Bramitob(®) or Pulmozyme(®)/TOBI(®) admixtures were generated with the PARI eFlow(®) rapid and aerodynamic particle sizing was performed via cascade impaction with the Next Generation Pharmaceutical Impactor. The stability tests revealed that neither the stability of tobramycin nor the stability of dornase alfa was affected by mixing the inhalation products. Cascade impaction showed no relevant changes in particle size distribution, Mass Median Aerodynamic Diameter, Geometric Standard Deviation and Fine Particle Fraction in comparison to aerodynamic parameters of the unmixed solutions. Thus, admixtures of Pulmozyme(®) and either Bramitob(®) or TOBI(®) can be designated as compatible for a 24 h period and simultaneous inhalation is feasible.

Lung function in adult patients with cystic fibrosis after using the eFlow rapid for one year

Background

The new generation nebuliser PARI eFlow^® rapid allows a highly efficient aerosol delivery at reduced inhalation time. However, lung function data during long-term use of this device are not available until now.

Methods

70 clinically stable adult cystic fibrosis patients participated in this observation study. Lung function tests were performed prospectively 12 weeks after and again 9 to 12 months after switching the inhalation device from a conventional jet nebulizer to the PARI eFlow^® rapid. Lung function data were collected retrospectively from the visits 1 year as well as 12 weeks prior to the switch-over. Lung function data for all time points were only available for 59 patients. Treatment time and patient's satification were recorded for both conventional and new nebuliser in all 70 patients.

Results

After 1 year of inhalation with eFlow^® rapid, the mean change in FEV1% was -- 1.4% (n = 59 patients). The decrease in FEV1 was smaller than the change in FEV1 after 1 year of inhalation with the conventional jet nebuliser (control period, -3.1%), although this difference was not statistically significant. The same effect was seen in MEF25[%] '(-2.6% with conventional nebuliser compared to --1.6% after eFlow^® rapid). Concerning the FVC, there was a greater improvement after 1 year of inhalation with the eFlow^® rapid than with the jet nebuliser (+ 2.9% vs. +1.1%). For PEF%, there was an increase during the control period, whereas after inhalation with eFlow^® rapid there was a decrease (+1.1% vs. --2.9%). All changes were not significantly different. The eFlow^® rapid reduced total daily inhalation time by two-thirds (conventional nebuliser: 31.1 min/day; eFlow^® rapid: 10.2 min/day, n = 70 patients)

Conclusion

Inhalation with the new nebuliser eFlow rapid does not alter FEV1, FVC or PEF significantly after 1 year of inhalation. The treatment time could be reduced significantly by the eFlow^® rapid.