Inhaled JAK Inhibitor GDC-0214 Nanoaggregate Powder Exhibits Improved Pharmacokinetic Profile in Rats Compared to the Micronized Form: Benefits of Thin Film Freezing.

Asthma is a common chronic disease affecting the airways in the lungs. The receptors of allergic cytokines, including interleukin (IL)-4, IL-5, and IL-13, trigger the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, which involves the pathogenesis of asthma. GDC-0214 is a JAK inhibitor that was developed as a potent and selective target for the treatment of asthma, specifically targeting the lungs. While inhaled GDC-0214 is a promising novel treatment option against asthma, improvement is still needed to achieve increased potency of the powder formulation and a reduced number of capsules containing powder to be inhaled. In this study, high-potency amorphous powder formulations containing GDC-0214 nanoaggregates for dry powder inhalation were developed using particle engineering technology, thin film freezing (TFF). A high dose per capsule was successfully achieved by enhancing the solubility of GDC-0214 and powder conditioning. Lactose and/or leucine as excipients exhibited optimum stability and aerosolization of GDC-0214 nanoaggregates, and aerosolization of the dose was independent of air flow through the device between 2 and 6 kPa pressure drops. In the rat PK study, formulation F20, which contains 80% GDC-0214 and 20% lactose, resulted in the highest AUC0-24h in the lungs with the lowest AUC0-24h in the plasma that corresponds to a 4.8-fold higher ratio of the lung-to-plasma exposures compared to micronized crystalline GDC-0214 powder administered by dry powder inhalation. Therefore, GDC-0214 nanoaggregates produced by TFF provided an improved dry powder for inhalation that can lead to enhanced therapeutic efficacy with a lower risk of systemic toxicity.

Emerging Process Modeling Capabilities for Dry Powder Operations for Inhaled Formulations.

Dry powder inhaler (DPI) products are commonly formulated as a mixture of micronized drug particles and large carrier particles, with or without additional fine particle excipients, followed by final powder filling into dose containment systems such as capsules, blisters, or reservoirs. DPI product manufacturing consists of a series of unit operations, including particle size reduction, blending, and filling. This review provides an overview of the relevant critical process parameters used for jet milling, high-shear blending, and dosator/drum capsule filling operations across commonly utilized instruments. Further, this review describes the recent achievements regarding the application of empirical and mechanistic models, especially discrete element method (DEM) simulation, in DPI process development. Although to date only limited modeling/simulation work has been accomplished, in the authors' perspective, process design and development are destined to be more modeling/simulation driven with the emphasis on evaluating the impact of material attributes/process parameters on process performance. The advancement of computational power is expected to enable modeling/simulation approaches to tackle more complex problems with better accuracy when dealing with real-world DPI process operations.

Pharmacokinetic Considerations for Optimizing Inhaled Spray-Dried Pyrazinoic Acid Formulations.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a leading cause of death with 1.6 million deaths worldwide reported in 2021. Oral pyrazinamide (PZA) is an integral part of anti-TB regimens, but its prolonged use has the potential to drive the development of PZA-resistant Mtb. PZA is converted to the active moiety pyrazinoic acid (POA) by the Mtb pyrazinamidase encoded by pncA, and mutations in pncA are associated with the majority of PZA resistance. Conventional oral and parenteral therapies may result in subtherapeutic exposure in the lung; hence, direct pulmonary administration of POA may provide an approach to rescue PZA efficacy for treating pncA-mutant PZA-resistant Mtb. The objectives of the current study were to (i) develop novel dry powder POA formulations, (ii) assess their feasibility for pulmonary delivery using physicochemical characterization, (iii) evaluate their pharmacokinetics (PK) in the guinea pig model, and (iv) develop a mechanism-based pharmacokinetic model (MBM) using in vivo PK data to select a formulation providing adequate exposure in epithelial lining fluid (ELF) and lung tissue. We developed three POA formulations for pulmonary delivery and characterized their PK in plasma, ELF, and lung tissue following passive inhalation in guinea pigs. Additionally, the PK of POA following oral, intravenous, and intratracheal administration was characterized in guinea pigs. The MBM was used to simultaneously model PK data following administration of POA and its formulations via the different routes. The MBM described POA PK well in plasma, ELF, and lung tissue. Physicochemical analyses and MBM predictions suggested that POA maltodextrin was the best among the three formulations and an excellent candidate for further development as it has: (i) the highest ELF-to-plasma exposure ratio (203) and lung tissue-to-plasma exposure ratio (30.4) compared with POA maltodextrin and leucine (75.7/16.2) and POA leucine salt (64.2/19.3) and (ii) the highest concentration in ELF (CmaxELF: 171 nM) within 15.5 min, correlating with a fast transfer into ELF after pulmonary administration (KPM: 22.6 1/h). The data from the guinea pig allowed scaling, using the MBM to a human dose of POA maltodextrin powder demonstrating the potential feasibility of an inhaled product.

Inhaled Adjunct Therapy with Second-Line Drug Candidates for Dose Reduction in Chemotherapeutic Regimens for Multi-drug-Resistant Tuberculosis.

Chemotherapy of multi-drug-resistant tuberculosis (TB) requires prolonged administration of multiple drugs. We investigated whether pulmonary delivery of minute doses of drugs, along with reduced oral doses of the same agents, would affect preclinical efficacy. We prepared dry powder inhalation (DPI) formulations comprising sutezolid (SUT), the second-generation pretomanid analog TBA-354 (TBA), or a fluorinated derivative of TBA-354 (32,625) in a matrix of the biodegradable polymer poly(L-lactide). We established formulation characteristics, doses inhaled by healthy mice, and preclinical efficacy in a mouse model of TB. Oral doses of 100 mg/kg/day or DPI doses of 0.25-0.5 mg/kg/day of drugs SUT, TBA-354, or 32,625 administered over 28 days were sub-optimally effective in reducing lung and spleen burden of Mycobacterium tuberculosis (Mtb) in infected mice. The addition of 0.25-0.5 mg/kg/day of SUT, TBA-354, or 32,625 as DPI to oral doses of 50 mg/kg/day was non-inferior in clearing Mtb from the lungs of infected mice. We concluded that adjunct therapy with inhaled second-line agents has the potential to reduce the efficacious oral dose.

Inhalable Nanoparticle-based Dry Powder Formulations for Respiratory Diseases: Challenges and Strategies for Translational Research.

The emergence of novel respiratory infections (e.g., COVID-19) and expeditious development of nanoparticle-based COVID-19 vaccines have recently reignited considerable interest in designing inhalable nanoparticle-based drug delivery systems as next-generation respiratory therapeutics. Among various available devices in aerosol delivery, dry powder inhalers (DPIs) are preferable for delivery of nanoparticles due to their simplicity of use, high portability, and superior long-term stability. Despite research efforts devoted to developing inhaled nanoparticle-based DPI formulations, no such formulations have been approved to date, implying a research gap between bench and bedside. This review aims to address this gap by highlighting important yet often overlooked issues during pre-clinical development. We start with an overview and update on formulation and particle engineering strategies for fabricating inhalable nanoparticle-based dry powder formulations. An important but neglected aspect in in vitro characterization methodologies for linking the powder performance with their bio-fate is then discussed. Finally, the major challenges and strategies in their clinical translation are highlighted. We anticipate that focused research onto the existing knowledge gaps presented in this review would accelerate clinical applications of inhalable nanoparticle-based dry powders from a far-fetched fantasy to a reality.

Esketamine inhaled as dry powder: Pharmacokinetic, pharmacodynamic and safety assessment in a preclinical study.

Ketamine and its enantiomer esketamine have gained much attention in recent years as potent, fast-acting agents for the management of treatment-resistant depression. However, an alternative to oral ketamine administration is required to ensure adequate systemic exposure as the drug undergoes extensive first-pass metabolism. We propose dry powder inhalation as a new esketamine delivery route. Here, we examine the pharmacokinetics, pharmacodynamics, toxicology and safety of this novel esketamine administration method. Esketamine (10 mg/kg) and ketamine racemate (20 mg/kg) were administered to rats by dry powder inhalation, intravenous injection or intratracheal instillation and the pharmacokinetics of these treatments were compared. Analyte concentration of ketamine stereoisomers and their metabolites was assessed by LC-MS/MS method. Esketamine showed a clinically relevant pharmacokinetic profile, with high bioavailability (62%) and relatively low maximum concentration peaks. Esketamine exhibited high penetration of the blood-brain barrier, but pharmacodynamic examinations of brain homogenates showed no changes in selected protein phosphorylation or expression analyzed by the immunoblotting method. We conducted GLP-compliant 14-day and 28-day general toxicity studies in rats and dogs, respectively, subjected to dry esketamine powder inhalation. The maximum daily dosages were 46.5 mg/kg and 36.5 mg/kg, respectively. We also performed pharmacological safety studies. Esketamine inhaled as dry powder had an expected safety profile consistent with its known pharmacological action. None of its observed effects were considered toxicologically significant. The pharmacological safety studies confirmed that the observed effects were transient and that inhaled esketamine had a good safety profile. Hence, our preclinical studies demonstrated that dry powder inhalation is a highly efficacious and safe delivery route for esketamine and may be a viable alternative administration route meriting further clinical development.

Improved Aerosolization Stability of Inhalable Tobramycin Powder Formulation by Co-Spray Drying with Colistin.

PURPOSE: Tobramycin shows synergistic antibacterial activity with colistin and can reduce the toxic effects of colistin. The purpose of this study is to prepare pulmonary powder formulations containing both colistin and tobramycin and to assess their in vitro aerosol performance and storage stability. METHODS: The dry powder formulations were manufactured using a lab-scale spray dryer. In vitro aerosol performance was measured using a Next Generation Impactor. The storage stability of the dry powder formulations was measured at 22°C and two relative humidity levels - 20 and 55%. Colistin composition on the particle surface was measured using X-ray photoelectron spectroscopy. RESULTS: Two combination formulations, with 1:1 and 1:5 molar ratios of colistin and tobramycin, showed fine particle fractions (FPF) of 85%, which was significantly higher than that of the spray dried tobramycin (45%). FPF of the tobramycin formulation increased significantly when stored for four weeks at both 20% and 55% RH. In contrast, FPF values of both combination formulations and spray dried colistin remained stable at both humidity levels. Particle surface of each combination was significantly enriched in colistin molecules; 1:5 combination showed 77% by wt. colistin. CONCLUSIONS: The superior aerosol performance and aerosolization stability of 1:1 and 1:5 combination formulations of colistin and tobramycin could be attributed to enrichment of colistin on the co-spray dried particle surface. The observed powder properties may be the result of a surfactant-like assembly of these colistin molecules during spray drying, thus forming a hydrophobic particle surface.

Preparation and Evaluation of Low-Dose Calcitriol Dry Powder Inhalation as Host-Directed Adjunct Therapy for Tuberculosis.

BACKGROUND: It is unclear whether Vitamin D is efficacious as a host-directed therapy (HDT) for patients of tuberculosis (TB). We investigated pulmonary delivery of the active metabolite of Vitamin D3, i.e., 1, 25-dihydroxy vitamin D3 (calcitriol) in a mouse model of infection with Mycobacterium tuberculosis (Mtb). METHODS: We optimized a spray drying process to prepare a dry powder inhalation (DPI) of calcitriol using a Quality by Design (QbD) approach. We then compared outcomes when Mtb-infected mice were treated with inhaled calcitriol at 5 ng/kg as a stand-alone intervention versus DPI as adjunct to standard oral anti-tuberculosis therapy (ATT). RESULTS: The DPI with or without concomitant ATT markedly improved the morphology of the lungs and mitigated histopathology in both the lungs and the spleens. The number of nodular lesions on the lung surface decreased from 43.7 ± 3.1 to 22.5 ± 3.9 with the DPI alone and to 9.8 ± 2.5 with DPI + ATT. However, no statistically significant induction of host antimicrobial peptide cathelicidin or reduction in bacterial burden was seen with the DPI alone. DPI + ATT did not significantly reduce the bacterial burden in the lungs compared to ATT alone. CONCLUSIONS: We concluded that HDT using the low dose calcitriol DPI contributed markedly to mitigation of pathology, but higher dose may be required to evoke significant induction of bactericidal host response and bactericidal activity in the lung.

Remdesivir powders manufactured by jet milling for potential pulmonary treatment of COVID-19.

Remdesivir is one of the effective drugs proposed for the treatment of coronavirus disease 2019 (COVID-19). However, the study on inhalable regimen is currently limited though COVID-19 is respiratory diseases and infects lung area. This work aims to prepare inhalable remdesivir formulations and verify their effectiveness through in vitro evaluations. Formulations containing different ratios of jet-milled inhalable remdesivir (5, 10, 20,40, and 70%) with excipients were produced and characterized in terms of the particle size distribution, particle morphology, flowability, water content, crystallinity, the water sorption and desorption capabilities, and the aerodynamic performance. Results indicating that drug loading are a vital factor in facilitating the dispersion of remdesivir dry powder, and the ternary excipient plays a negligible role in improving aerosol performance. Besides, the 70% remdesivir with lactose carrier (70% RD-Lac) was physically stable and retain high aerosol performance after conditioned at 40 °C and 75% RH for a month. Therefore, formulation 70% RD-Lac might be recommended as a candidate product for the potential treatment of COVID-19.

Enhanced Aerosolization of High Potency Nanoaggregates of Voriconazole by Dry Powder Inhalation.

Invasive pulmonary aspergillosis is a deadly fungal infection with a high mortality rate, particularly in patients having undergone transplant surgery. Voriconazole, a triazole antifungal pharmaceutical product, is considered as a first-line therapy for invasive pulmonary aspergillosis, and exhibits efficacy even for patients who have failed other antifungal drug therapies. The objective of this study is to develop high potency nanoaggregates of crystalline voriconazole composition for dry powder inhalation using the particle engineering process, thin film freezing. In this study, mannitol at low concentrations acted as a surface texture-modifying agent, and we evaluated the physicochemical and aerodynamic properties of the voriconazole formulations containing different amounts of mannitol. In vitro aerosol performance data demonstrated that powder formulations consisting of 90 to 97% (w/w) voriconazole were the optimum for inhalation with a fine particle fraction (% of delivered dose) as high as 73.6 ± 3.2% and mass median aerodynamic diameter of 3.03 ± 0.17 µm when delivered by a commercially available device. The thin film freezing process enabled phase-separated submicron crystalline mannitol to be oriented such as to modify the surface texture of the crystalline voriconazole nanoaggregates, thus enhancing their aerosolization. Addition of as low as 3% (w/w) mannitol significantly increased the fine particle fraction (% of metered dose) of voriconazole nanoaggregates when compared to compositions without mannitol (40.8% vs 24.6%, respectively). The aerosol performance of the voriconazole nanoaggregates with 5% (w/w) mannitol was maintained for 13 months at 25 °C/60% RH. Therefore, voriconazole nanoaggregates having low amounts of surface texture-modifying mannitol made by thin film freezing are a feasible local treatment option for invasive pulmonary aspergillosis with high aerosolization efficiency and drug loading for dry powder inhalation.

Effect of Particle-Wall Interaction and Particle Shape on Particle Deposition Behavior in Human Respiratory System.

Dry powder inhalation (DPI) has attracted much attention as a treatment for respiratory diseases owing to the large effective absorption area in a human respiratory system. Understanding the drug particle motion in the respiratory system and the deposition behavior is necessary to improve the efficiency of DPI. We conducted computer simulations using a model coupling a discrete element method and a computational fluid dynamics method (DEM-CFD) to evaluate the particle deposition in human respiratory system. A simple artificial respiratory model was developed, which numerically investigated the effect of particle properties and inhalation patterns on the particle deposition behavior. The DEM-CFD simulations demonstrated that the smaller- and lower-density particles showed higher reachability into the simple respiratory model, and the particle arrival ratio to the deep region strongly depended on the aerodynamic diameter. The particle arrival ratio can be described as an exponential function of the aerodynamic diameter. Furthermore, the exponential relationship between the particle reachability into the depth of the simple respiratory model and the aerodynamic diameter predicted the particle aerodynamic diameter based on the required reachability. The particle shape also had an impact on the particle deposition behavior. The rod-like particles with a larger aspect ratio indicated higher reachability into the depth of the simple respiratory model. This was attributed to the high velocity motion of the particles whose long axis was in the direction of the deep region.

Pulmonary and Regional Deposition of Nebulized and Dry Powder Aerosols in Ferrets.

The utilization of ferrets as a non-clinical model for disease is rapidly increasing within drug development. Many of these models include respiratory diseases that involve targeted drug delivery via nose-only inhalation. While the deposition patterns within other non-clinical models (mice, rats, canines, and non-human primates) have been well studied, the local and regional deposition of aerosols in ferrets has not been well characterized. Therefore, inhalation aerosols were developed, radiolabeled and the radiolabeling methods validated to support SPECT-CT imaging and quantification of regional deposition within ferrets. The studies were conducted with one liquid formulation and one dry powder formulation (two concentrations of dry powder). Additionally, both aerosols were polydisperse and therefore reflect the majority of pharmaceutical aerosols. Overall, the studies showed lung deposition fractions between 5 and 10% with median aerodynamic particle sizes of 2.5 and 2.8 µm. The lung deposition fraction of the liquid aerosol was ~ 9%, nearly double observed in rats with a similarly sized aerosol. Analysis of respiratory tract (oropharynx, laryngopharynx, trachea, bifurcation area, and lung) deposition indicates increased deposition of the liquid aerosol compared to the dry powder aerosol, however, when this analysis was refined to the pulmonary region (trachea, bifurcation, and lung) the deposition was similar between formulations. These data provide the first description of the regional deposition of inhalation aerosols in ferrets with standard nose-only inhalation procedures. These data can be used for calculations of both total and regional doses within ferret inhalation drug delivery.

Pharmacokinetics, Metabolism, and Partial Biodistribution of "Pincer Therapeutic" Nitazoxanide in Mice following Pulmonary Delivery of Inhalable Particles.

Nitazoxanide (NTZ) induces autophagy in mammalian cells and also has mycobactericidal activity, displaying a two-pronged therapeutic effect, on the host as well as the pathogen. The pharmacokinetics and biodistribution of inhaled NTZ were investigated. Particles containing NTZ in a matrix of PLGA were prepared by spray drying. HPLC and LC-MS/MS methods were developed and validated. Particles were administered as inhalations to mice. Drug concentrations in plasma and tissues were estimated at different time points. Drug loading (∼36%), entrapment efficiency (>90%), and the conversion of NTZ into metabolites in plasma and lung homogenates were assessed satisfactorily by HPLC. NTZ pharmacokinetics and biodistribution following intravenous administration or inhalation were established by LC-MS. NTZ converted into tizoxanide (99% in 30 min) and other metabolites. Pulmonary delivery of NTZ entrapped in particles increased the half-life of the drug by factors of 3, 12, and 200 in the plasma, lung tissue, and alveolar macrophages, respectively. Targeted delivery and prolonged lung retention along with dose sparing of the kidneys was observed upon pulmonary delivery as compared to intravenous administration.

Preparation and Preclinical Evaluation of Inhalable Particles Containing Rapamycin and Anti-Tuberculosis Agents for Induction of Autophagy.

PURPOSE: Mycobacterium tuberculosis (Mtb) inhibits host defense mechanisms, including autophagy. We investigated particles containing rapamycin (RAP) alone or in combination with isoniazid (INH) and rifabutin (RFB) for: targeting lung macrophages on inhalation; inducing autophagy; and killing macrophage-resident Mtb and/or augmenting anti-tuberculosis (TB) drugs. METHODS: PLGA and drugs were spray-dried. Pharmacokinetics, partial biodistribution (LC-MS/MS) and efficacy (colony forming units, qPCR, acid fast staining, histopathology) in mice following dry powder inhalation were evaluated. RESULTS: Aerodynamic diameters of formulations were 0.7-4.7 µm. Inhaled particles reached deep lungs and were phagocytosed by alveolar macrophages, yielding AUC0-48 of 102 compared to 0.1 µg/ml × h obtained with equivalent intravenous dose. RAP particles induced more autophagy in Mtb-infected macrophages than solutions. Inhaled particles containing RAP alone in daily, alternate-day and weekly dosing regimens reduced bacterial burden in lungs and spleens, inducing autophagy and phagosome-lysosome fusion. Inhalation of particles containing RAP with INH and RFB cleared the lungs and spleens of culturable bacteria. CONCLUSIONS: Targeting a potent autophagy-inducing agent to airway and lung macrophages alone is feasible, but not sufficient to eliminate Mtb. Combination of macrophage-targeted inhaled RAP with classical anti-TB drugs contributes to restoring tissue architecture and killing Mtb.

Effects of the deformation and size of the upper airway on the deposition of aerosols.

Aerosol drug delivery in the human airway is significantly affected by the morphology and size of the airway. This work developed a CFD-DEM model to simulate and analyze air flow and powder dynamics in combined inhaler-airway systems with different degrees of airway deformation (non-deformed, 50%, and 75% deformed) and sizes (adult, 0.80, and 0.62 scaled). The airways were generated based on a regular airway constructed from the MRI images through finite element method (for deformed airways) or scaling-down (for smaller airways). The airways were connected to Turbuhaler® through a connector. The results showed that under the same flow rate, the variation in the airway geometry and size had a minimum impact on the flow field and powder deposition in the device and the connector. However, deformation caused more particle deposition in the deformed region. Notably, the airway with 50% deformation had the most particles passing through the airway with the largest particle sizes due to its lower air velocity in the deformed area. Reducing airway size resulted in more powder deposition on the airway, particularly at the pharynx and mouth regions. This was because, with the same flow rate, the flow velocity in the smaller airway was higher, causing more particle-wall collisions in the mouth and pharynx regions. More importantly, the deposition efficiency in the 0.62-scaled airway was significantly higher than the other two airways, highlighting the importance of the different administration of aerosol drugs for young children.

Pulmonary administration of cross-linked chitosan nanoparticles of genistein for regulating blood glucose.

The research study focused on the development and characterization of sustained release formulation of genistein (GEN)-loaded chitosan (CS) nanoparticles to deliver in the form of dry powder inhaler (DPI) via pulmonary route to offer higher stability and anti-diabetic activity. The GEN-loaded nanoparticles were prepared by cross-linking reaction of CS and sodium hexametaphosphate (SHMP). The optimized formulation displayed particle size (PS) of 684.2 ± 26.5 nm, zeta potential (ZP) of 19.6 ± 4.50 mV, % entrapment efficiency (% EE) of 87.33 ± 8.46 % and drug release profile of 85.48 ± 5.50 % for 48 h. The in-vivo studies exhibited a superior sustained release formulation of GEN in the regulation of blood glucose levels (BGLs). The powder showed the emitted fraction (EF) of 86.76 % and effective inhalation index (EI) of 85.41 %. The reduction of BGLs (85 %) was observed in the diabetic group. This might be due to the inhibition of proliferation of pancreatic ß-cells (growth factor inhibition targeting cAMP and ERK1/2 pathway), antioxidative activity, reducing insulin resistance, and the adipose tissue mass and alteration of the hepatic glucose metabolism. Hence, these results proved the delivery of GEN in the form of DPI system as a favorable route for treating type-1 diabetes mellitus with a longer duration of action.

Macrophage-targeted versus free calcitriol as host-directed adjunct therapy against Mycobacterium tuberculosis infection in mice is bacteriostatic and mitigates tissue pathology.

Host-directed therapy (HDT) with vitamin D in tuberculosis (TB) is beneficial only if the subject is deficient in vitamin D. We investigated pulmonary delivery of 1,25-dihydroxy vitamin D3 (calcitriol) in mice infected with Mycobacterium tuberculosis (Mtb). We made two kinds of dry powder inhalations (DPI)- soluble particles or poly(lactide) (PLA) particles. We compared treatment outcomes when infected mice were dosed with a DPI alone or as an adjunct to standard oral anti-TB therapy (ATT). Mice infected on Day 0 were treated between Days 28-56 and followed up on Days 57, 71, and 85. Neither DPI significantly reduced Mtb colony forming units (CFU) in the lungs. Combining DPI with ATT did not significantly augment bactericidal activity in the lungs, but CFU were 2-log lower in the spleen. CFU showed a rising trend on stopping treatment, sharper in groups that did not receive calcitriol. Lung morphology and histology improved markedly in animals that received PLA DPI; with or without concomitant ATT. Groups receiving soluble DPI had high mortality. DPI elicited cathelicidin, interleukin (IL)-1 and induced autophagy on days 57, 71, and 85. Macrophage-targeted calcitriol is therefore bacteriostatic, evokes innate microbicidal mechanisms, and mitigates pathology arising from the host response to Mtb.

Triple combination dry powder formulation of pretomanid, moxifloxacin, and pyrazinamide for treatment of multidrug-resistant tuberculosis.

Both latent and multidrug-resistant tuberculosis (TB) have been causing significant concern worldwide. A novel drug, pretomanid (PA-824), has shown a potent bactericidal effect against both active and latent forms of Mycobacterium tuberculosis (MTb) and a synergistic effect when combined with pyrazinamide and moxifloxacin. This study aimed to develop triple combination spray dried inhalable formulations composed of antitubercular drugs, pretomanid, moxifloxacin, and pyrazinamide (1:2:8 w/w/w), alone (PaMP) and in combination with an aerosolization enhancer, L-leucine (20 % w/w, PaMPL). The formulation PaMPL consisted of hollow, spherical, dimpled particles (<5 µm) and showed good aerosolization behaviour with a fine particle fraction of 70 %. Solid-state characterization of formulations with and without L-leucine confirmed the amorphous nature of moxifloxacin and pretomanid and the crystalline nature of pyrazinamide with polymorphic transformation after the spray drying process. Further, the X-ray photoelectron spectroscopic analysis revealed the predominant surface composition of L-leucine on PaMPL dry powder particles. The dose-response cytotoxicity results showed pyrazinamide and moxifloxacin were non-toxic in both A549 and Calu-3 cell lines up to 150 µg/mL. However, the cell viability gradually decreased to 50 % when the pretomanid concentration increased to 150 µg/mL. The in vitro efficacy studies demonstrated that the triple combination formulation had more prominent antibacterial activity with a minimum inhibitory concentration (MIC) of 1 µg/mL against the MTb H37Rv strain as compared to individual drugs. In conclusion, the triple combination of pretomanid, moxifloxacin, and pyrazinamide as an inhalable dry powder formulation will potentially improve treatment efficacy with fewer systemic side effects in patients suffering from latent and multidrug-resistant TB.

Inhaled delivery of cetuximab-conjugated immunoliposomes loaded with afatinib: A promising strategy for enhanced non-small cell lung cancer treatment.

Afatinib (AT), an FDA-approved aniline-quinazoline derivative, is a first-line treatment for metastatic non-small cell lung cancer (NSCLC). Combining it with cetuximab (CX), a chimeric human-murine derivative immunoglobulin-G1 monoclonal antibody (mAb) targeting the extracellular domain of epidermal growth factor receptor (EGFR), has shown significant improvements in median progression-free survival. Previously, we developed cetuximab-conjugated immunoliposomes loaded with afatinib (AT-MLP) and demonstrated their efficacy against NSCLC cells (A549 and H1975). In this study, we aimed to explore the potential of pulmonary delivery to mitigate adverse effects associated with oral administration and intravenous injection. We formulated AT-MLP dry powders (AT-MLP-DPI) via freeze drying using tert-butanol and mannitol as cryoprotectants in the hydration medium. The physicochemical and aerodynamic properties of dry powders were well analyzed firstly. In vitro cellular uptake and cytotoxicity study revealed concentration- and time-dependent cellular uptake behavior and antitumor efficacy of AT-MLP-DPI, while Transwell assay demonstrated the superior inhibitory effects on NSCLC cell invasion and migration. Furthermore, in vivo pharmacokinetic study showed that pulmonary delivery of AT-MLP-DPI significantly increased bioavailability, prolonged blood circulation time, and exhibited higher lung concentrations compared to alternative administration routes and formulations. The in vivo antitumor efficacy study carried on tumor-bearing nude mice indicated that inhaled AT-MLP-DPI effectively suppressed lung tumor growth.

Novel inhaled andrographolide for treatment of lung cancer: In vitro assessment.

Andrographolide is a plant-based compound that showed promising activity against lung cancer. However, the compound's poor water solubility and low bioavailability limit its oral administration. Inhaled drug delivery of andrographolide is highly favourable as it delivers active ingredients directly into the affected lungs. In the current study, we compared in vitro aerosol performance, anti-cancer activity and storages stability of two (2) inhalable andrographolide formulations. Formulation 1 was prepared using precipitation and spray drying techniques, while Formulation 2 was prepared via direct spray drying technique. Drug morphology and physicochemical properties were confirmed using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. In vitro aerosol dispersion profile was evaluated using the next-generation impactor (NGI). Formulation 1 consisted of elongated crystals while Formulation 2 was made up of amorphous spherical particles. Both formulations had an inhalable fraction (<5 µm) of more than 40 %, making them suitable for pulmonary drug delivery. The formulations also showed an IC25 of less than 100 µg/mL against the human lung carcinoma cells (A549). Formulation 1 and 2 was stable in a vacuum condition at 30 °C for up to 6 and 3 months, respectively. Novel inhalable andrographolide dry powders were successfully produced with a good aerosol profile, potent anti-cancer activity and adequate storage stability, which deserve further in vivo investigations.