Co-Delivery of D-LAK Antimicrobial Peptide and Capreomycin as Inhaled Powder Formulation to Combat Drug-Resistant Tuberculosis.

INTRODUCTION: The emergence of multidrug-resistant (MDR) Mycobacterium tuberculosis (Mtb) posed a severe challenge to tuberculosis (TB) management. The treatment of MDR-TB involves second-line anti-TB agents, most of which are injectable and highly toxic. Previous metabolomics study of the Mtb membrane revealed that two antimicrobial peptides, D-LAK120-A and D-LAK120-HP13, can potentiate the efficacy of capreomycin against mycobacteria. AIMS: As both capreomycin and peptides are not orally available, this study aimed to formulate combined formulations of capreomycin and D-LAK peptides as inhalable dry powder by spray drying. METHODS AND RESULTS: A total of 16 formulations were prepared with different levels of drug content and capreomycin to peptide ratios. A good production yield of over 60% (w/w) was achieved in most formulations. The co-spray dried particles exhibited spherical shape with a smooth surface and contained low residual moisture of below 2%. Both capreomycin and D-LAK peptides were enriched at the surface of the particles. The aerosol performance of the formulations was evaluated with Next Generation Impactor (NGI) coupled with Breezhaler®. While no significant difference was observed in terms of emitted fraction (EF) and fine particle fraction (FPF) among the different formulations, lowering the flow rate from 90 L/min to 60 L/min could reduce the impaction at the throat and improve the FPF to over 50%. CONCLUSIONS: Overall, this study showed the feasibility of producing co-spray dried formulation of capreomycin and antimicrobial peptides for pulmonary delivery. Future study on their antibacterial effect is warranted.

Edge activators and a polycationic polymer enhance the formulation of porous voriconazole nanoagglomerate for the use as a dry powder inhaler.

PURPOSE: Voriconazole has both low aqueous solubility and stability. We hypothesize that designing voriconazole in the form of a nano powder inhaler at a geometric diameter within 1-5 µm will enhance its stability and solubility. Therefore, we prepared nanoagglomerates of voriconazole which will collapse in the lungs to reform the nanoparticles. METHOD: The nanoparticles were formulated using both stearic acid and sodium deoxycholate as edge activators. Osmogenic polycation polyethyleneimine (PEI) was used to form agglomerates of controllable size. RESULTS: Voriconazole nanoparticles and agglomerates showed a significant higher cumulative drug release than the pure powder (p < 0.05) with R(2 )=( )0.95. Small-sized particles were formed (353 nm), while their zeta potential was -30.7 mV. The agglomerates were 2.7 µm in size and their zeta potential was -20.9 mV. The formation of porous agglomerates was confirmed using a transmission electron microscope. Cascade impactor was used to evaluate the aerodynamic properties of the nanoparticles and the agglomerates. The aerodynamic characterization of the nanoparticles and the agglomerates resulted in a significant smaller mass median aerodynamic diameter (MMAD) (p < 0.05) and higher fine particle dose (FPD) (p < 0.01), fine particle fraction (FPF) (p < 0.01), and total emitted dose (TED) (p < 0.01) than the pure powder. CONCLUSION: The results suggest that using the combination of edge activators and diluted polycationic polymer solution provides porous voriconazole nanoagglomerates in a respirable range, which is proved successful in enhancing both the deposition and the dissolution of water insoluble-drugs in the lung.

Effects of different mesh nebulizer sources on the dispersion of powder formulations produced with a new small-particle spray dryer.

The objective of this study was to explore the aerosolization performance of powders produced with different mesh nebulizer sources in the initial design of a new small-particle spray dryer system. An aqueous excipient enhanced growth (EEG) model formulation was spray dried using different mesh sources and the resulting powders were characterized based on (i) laser diffraction, (ii) aerosolization with a new infant air-jet dry powder inhaler, and (iii) aerosol transport through an infant nose-throat (NT) model ending with a tracheal filter. While few differences were observed among the powders, the medical-grade Aerogen Solo (with custom holder) and Aerogen Pro mesh sources were selected as lead candidates that produced mean fine particle fractions <5 µm and <1 µm in ranges of 80.6-77.4% and 13.1-16.0%, respectively. Improved aerosolization performance was achieved at a lower spray drying temperature. Lung delivery efficiencies through the NT model were in the range of 42.5-45.8% for powders from the Aerogen mesh sources, which were very similar to previous results with a commercial spray dryer. Ultimately, a custom spray dryer that can accept meshes with different characteristics (e.g., pore sizes and liquid flow rates) will provide particle engineers greater flexibility in producing highly dispersible powders with unique characteristics.

Preparation and Characterization of Inhalable Ivermectin Powders as a Potential COVID-19 Therapy.

Background: Ivermectin has received worldwide attention as a potential COVID-19 treatment after showing antiviral activity against SARS-CoV-2 in vitro. However, the pharmacokinetic limitations associated with oral administration have been postulated as limiting factors to its bioavailability and efficacy. These limitations can be overcome by targeted delivery to the lungs. In this study, inhalable dry powders of ivermectin and lactose crystals were prepared and characterized for the potential treatment of COVID-19. Methods: Ivermectin was co-spray dried with lactose monohydrate crystals and conditioned by storage at two different relative humidity points (43% and 58% RH) for a week. The in vitro dispersion performance of the stored powders was examined using a medium-high resistance Osmohaler connecting to a next-generation impactor at 60 L/min flow rate. The solid-state characteristics including particle size distribution and morphology, crystallinity, and moisture sorption profiles of raw and spray-dried ivermectin samples were assessed by laser diffraction, scanning electron microscopy, Raman spectroscopy, X-ray powder diffraction, thermogravimetric analysis, differential scanning calorimetry, and dynamic vapor sorption. Results: All the freshly spray-dried formulation (T0) and the conditioned samples could achieve the anticipated therapeutic dose with fine particle dose of 300 µg, FPFrecovered of 70%, and FPFemitted of 83%. In addition, the formulations showed a similar volume median diameter of 4.3 µm and span of 1.9. The spray-dried formulations were stable even after conditioning and exposing to different RH points as ivermectin remained amorphous with predominantly crystalline lactose. Conclusion: An inhalable and stable dry powder of ivermectin and lactose crystals was successfully formulated. This powder inhaler ivermectin candidate therapy appears to be able to deliver doses that could be safe and effective to treat the SARS-COV-2 infection. Further development of this therapy is warranted.

Pharmacokinetics and safety of inhaled ivermectin in mice as a potential COVID-19 treatment.

Pharmacokinetic limitations associated with oral ivermectin may limit its success as a potential COVID-19 treatment based on in vitro experiments which demonstrate antiviral efficacy against SARS-CoV-2 at high concentrations. Targeted delivery to the lungs is a practical way to overcome these limitations and ensure the presence of a therapeutic concentration of the drug in a clinically critical site of viral pathology. In this study, the pharmacokinetics (PK) and safety of inhaled dry powders of ivermectin with lactose were investigated in healthy mice. Female BALB/c mice received ivermectin formulation by intratracheal administration at high (3.15 mg/kg) or low doses (2.04 mg/kg). Plasma, bronchoalveolar lavage fluid (BALF), lung, kidney, liver, and spleen were collected at predetermined time points up to 48 h and analyzed for PK. Histological evaluation of lungs was used to examine the safety of the formulation. Inhalation delivery of ivermectin formulation showed improved pharmacokinetic performance as it avoided protein binding encountered in systemic delivery and maintained a high exposure above the in vitro antiviral concentration in the respiratory tract for at least 24 h. The local toxicity was mild with less than 20% of the lung showing histological damage at 24 h, which resolved to 10% by 48 h.

Dual targeting powder formulation of antiviral agent for customizable nasal and lung deposition profile through single intranasal administration.

Unpredictable outbreaks due to respiratory viral infections emphasize the need for new drug delivery strategies to the entire respiratory tract. As viral attack is not limited to a specific anatomic region, antiviral therapy that targets both the upper and lower respiratory tract would be most effective. This study aimed to formulate tamibarotene, a retinoid derivative previously reported to display broad-spectrum antiviral activity against influenza and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), as a novel dual particle size powder formulation that targets both the nasal cavity and the lung by a single route of intranasal administration. Spray freeze drying (SFD) and spray drying (SD) techniques were employed to prepare tamibarotene powder formulations, and cyclodextrin was used as the sole excipient to enhance drug solubility. With the employment of appropriate atomizing nozzles, particles of size above 10 µm and below 5 µm could be produced for nasal and lung deposition, respectively. The aerosol performance of the powder was evaluated using Next Generation Impactor (NGI) coupled with a glass expansion chamber and the powder was dispersed with a nasal powder device. By blending powder of two different particle sizes, a single powder formulation with dual aerosol deposition characteristic in both the nasal and pulmonary regions was produced. The aerosol deposition fractions in the nasal cavity and pulmonary region could be modulated by varying the powder mixing ratio. All dry powder formulations exhibited spherical structures, amorphous characteristics and improved dissolution profile as compared to the unformulated tamibarotene. Overall, a novel dual targeting powder formulation of tamibarotene exhibiting customizable aerosol deposition profile was developed. This exceptional formulation strategy can be adopted to deliver other antimicrobial agents to the upper and lower airways for the prevention and treatment of human respiratory infections.

Spray-Dried Powder Formulation of Capreomycin Designed for Inhaled Tuberculosis Therapy.

Multi-drug-resistant tuberculosis (MDR-TB) is a huge public health problem. The treatment regimen of MDR-TB requires prolonged chemotherapy with multiple drugs including second-line anti-TB agents associated with severe adverse effects. Capreomycin, a polypeptide antibiotic, is the first choice of second-line anti-TB drugs in MDR-TB therapy. It requires repeated intramuscular or intravenous administration five times per week. Pulmonary drug delivery is non-invasive with the advantages of local targeting and reduced risk of systemic toxicity. In this study, inhaled dry powder formulation of capreomycin targeting the lung was developed using spray drying technique. Among the 16 formulations designed, the one containing 25% capreomycin (w/w) and spray-dried at an inlet temperature of 90 °C showed the best overall performance with the mass median aerodynamic diameter (MMAD) of 3.38 µm and a fine particle fraction (FPF) of around 65%. In the pharmacokinetic study in mice, drug concentration in the lungs was approximately 8-fold higher than the minimum inhibitory concentration (MIC) (1.25 to 2.5 µg/mL) for at least 24 h following intratracheal administration (20 mg/kg). Compared to intravenous injection, inhaled capreomycin showed significantly higher area under the curve, slower clearance and longer mean residence time in both the lungs and plasma.

Inhalable Hydroxychloroquine Powders for Potential Treatment of COVID-19.

Background: Hydroxychloroquine (HCQ) is one of the repurposed drugs proposed for the treatment of coronavirus disease 2019 (COVID-19). However, all the published clinical trials involve oral administration of the drug, although the disease is primarily a respiratory one. Direct inhaled delivery could reduce the side effects associated with oral use and ensure a high concentration of the drug in the lungs. In this study, inhalable HCQ powders were prepared and characterized for potential COVID-19 therapy. Methods: Hydroxychloroquine sulfate (HCQ-sul) was jet milled (JM) followed by conditioning by storage at different relative humidities (43%, 53%, 58%, and 75% RHs) for 7 days. The solid-state properties, including particle morphology and size distribution, crystallinity, and vapor moisture profiles of HCQ-sul samples, were characterized by scanning electron microscopy, laser diffraction, X-ray powder diffraction, differential scanning calorimetry, thermogravimetric analysis, and dynamic water vapor sorption. The aerosol performance of the HCQ-sul powders was assessed using a medium-high resistance Osmohaler coupling to a next-generation impactor (NGI) at a flow rate of 60 L/min. Results: The jet-milled powder showed a volume median diameter of 1.7 µm (span 1.5) and retained the same crystalline form as the raw HCQ-sul. A small amount of amorphous materials was present in the jet-milled HCQ-sul, which was convertible to the stable, crystalline state after conditioning at 53%, 58%, and 75% RH. The recovered fine particle fraction (FPF)recovered and the emitted fine particle fraction (FPFemitted) of the HCQ-sul sample immediately after jet milling and the samples after conditioning at 43%, 53%, and 58% RH were similar at ∼43% and 61%, respectively. In contrast, the sample having conditioned at 75%RH showed lower corresponding values at 33% and 26% respectively, due to the formation of solid bridges caused by excessive moisture. Conclusion: Inhalable crystalline powders of HCQ-sul were successfully prepared, which can be used for clinical testing as a potential inhaled COVID-19 treatment.

Characterization of excipient enhanced growth (EEG) tobramycin dry powder aerosol formulations.

Spray drying can be utilized to produce highly dispersible powder aerosol formulations. However, these formulations are known to be hygroscopic, leading to potential solid-state stability and aerosol performance issues. This study aims to investigate if control of the spray drying particle formation conditions could be employed to improve the solid-state stability and alter the aerosol performance of tobramycin EEG formulations. Eight formulations were prepared, each had the same drug:excipient ratio of 60%w/w tobramycin, 20% w/w l-leucine, 18% w/w mannitol, and 2% w/w poloxamer 188. An experimental design matrix was performed with drying air water content of 1 or 10 g/m3 and spray drying solution l-leucine concentrations of 4.6, 7.6, 15.2 or 23.0 mmol/L. The particle size, morphology and crystallinity of spray dried formulations were characterized together with their dynamic moisture vapor sorption and aerosol performance. Higher crystallization and glass transition %RH were observed for the formulations spray dried using drying air with higher water content indicating more stable characteristics. Initial screening using a handheld dry powder inhaler of the realistic aerosol performance revealed that neither changing l-leucine concentration nor the drying gas water content affect the in-vitro expected lung dose. However, using a novel positive pressure inhaler, formulations produced using spray drying solutions with lower l-leucine concentrations showed better aerosol performance with MMAD around 2 µm and FPF < 5 µm around 80%.

Investigation of Lung Pharmacokinetic of the Novel PDE4 Inhibitor CHF6001 in Preclinical Models: Evaluation of the PreciseInhale Technology.

BACKGROUND: Preclinical evaluation of new chemical entities (NCEs) designed to be administered by inhalation route requires lung administration to rodents, especially in the discovery phase. Different administration methods have been used until now, but more efforts are required to obtain controlled and reproducible lung deposition when only small amounts of neat powder material are available. METHODS: The PreciseInhale platform used in the present study enables well-controlled powder aerosol exposures with only small amounts of micronized neat material, providing data on inhalation pharmacokinetic (PK) of NCEs at a very early stage. The DustGun aerosol technology uses compressed air to generate a respirable aerosol from milligram-amounts of powder that is delivered to one animal at a time. The new methodology was used to investigate the inhalation PK and lung retention in the rat of the novel Chiesi PDE4 inhibitor CHF6001 in three exposure models of the PreciseInhale platform: nose-only, intratracheally intubated rat, and the isolated, ventilated, and perfused rat lung. Results were compared with data from two other pulmonary delivery systems commonly used in preclinical studies: liquid instillation and powder insufflation. RESULTS: Administration of micronized CHF6001 using the PreciseInhale system yielded lung exposures in the same range as the other tested devices, but the reproducibility in lung deposition was improved. The initial amount of CHF6001 in lungs at the first sampling time point was close to the predetermined target dose. Tracheal deposition with PreciseInhale (0.36 ± 0.22 µg) was significantly less than with other tested delivery systems: PennCentury (23.7 ± 3.2 µg) and Airjet (25.6 ± 7.2 µg). CONCLUSIONS: The PreciseInhale platform enabled the administration of CHF6001 powder with good accuracy and reproducibility, with low tracheal deposition. The new platform can be used at an early discovery stage to obtain inhalatory PK data for respirable aerosols of neat NCE powder without excipients and with minimal use of dry powder formulation work.

A Novel In-Line Delivery System to Administer Dry Powder Mannitol to Mechanically Ventilated Patients.

BACKGROUND: Mechanically ventilated patients commonly suffer from ventilator-associated pneumonia, hypoxemia, and other lower respiratory tract infection as a result of pathogen colonization and poor sputum clearance. Consequently, there is a high rate of morbidity and mortality in these patients. Dry powder mannitol increases sputum clearance, and therefore, we developed a system to administer it to mechanically ventilated patients without disconnection from the ventilator. METHODS: The inspiratory line from a ventilator was split by using a three-way valve into two parallel lines where one contains a humidifier for normal breathing cycle and the other line contains a dry powder inhaler (Osmohaler™). The inspiratory air went through the dry powder line and aerosolized the mannitol powder only when its administration to a patient is required. We determined the delivered dose and particle size distributions of emitted aerosols in vitro from 9.5 mm endotracheal and 7.5 mm tracheostomy tubes, with inspiratory airflow of 60, 70, and 80 L/min. RESULTS: This novel setup was able to deliver 24.6% ± 3.33% of the 160 mg loaded dose mannitol powder (4 × 40 mg capsules) and 26.7% ± 2.19% of the 320 mg dose (4 × 80 mg capsules) when the endotracheal tube was used. With the shorter tracheostomy tube, the delivery dose increased to 35.6% ± 3.01% and 39.5% ± 2.04% of the 160 and 320 mg doses, respectively. The volume median diameters of the aerosols were in the respirable range with the largest value being 5.17 ± 0.87 µm. CONCLUSIONS: This delivery system has been shown to consistently deliver a high respirable dose of mannitol powder. Since this setup does not require disconnection of patients from the ventilator, it is safer for hypoxemic patients and easier to be adapted in a real clinical use.