Dry Powder Research Articles

On the use of slurry as an alternative to dry powder for laser powder bed fusion of 316L stainless steel

Laser powder bed fusion (LPBF) is a well-established additive manufacturing process for producing high-quality metal components with unparallelled design freedom. However, LPBF also has its limitations, including a limited materials palette, low productivity and high costs, mainly due to the expensive feedstock powders. These powders must meet highly stringent requirements regarding particle size (15–45μm), particle size distribution (mono-modal) and morphology (spherical), which is achievable only through expensive gas- and plasma-atomised powders. This paper investigates slurry-LPBF as an alternative to conventional dry powder LPBF. The use of slurry removes some of the stringent powder requirements by allowing deposition of smaller particles with a variety of particle morphologies. Slurry-LPBF can therefore increase the useful yield of the atomisation process and expand the materials palette for LPBF, by enabling the use of powders for which atomised variants are not commercially available. This study used 316L stainless steel powder with an average particle size <18μm. An existing slurry-LPBF machine was re-designed and re-built, allowing successful slurry processing. Two optimal parameter sets were obtained, resulting in component density of 99.4%. Tensile testing revealed an ultimate tensile strength (UTS) of 622 ± 2 MPa and an elongation at break of 66 ± 2%. These results are consistent, and fall within the range of reported values in literature for dry-powder LPBF, with the UTS being on the lower side of the range, whilst elongation at break being on the higher side.

Analysis of the Influence of Nozzle Structure of Dry Powder Fire Extinguishing System on Supersonic Jet Characteristics

Analysis of the Influence of Nozzle Structure of Dry Powder Fire Extinguishing System on Supersonic Jet Characteristics

Modification and Application Performance Study of Ultra-Fine Dry Powder Extinguishing Agent.

Ultra-fine dry powder extinguishing agent (UDPEA) is a promising alternative to Halon agents in aviation firefighting. The formulation of UDPEAs should balance environmental friendliness and practical engineering requirements, including high extinguishing efficiency, excellent flowability, and prolonged anti-reignition. This study investigates the effects of three modification methods (single perfluorooctyl triethoxysilane (FOTS), single N-(3-Triethoxysilylpropyl)perfluoro(2,5-dimethyl-3,6-dioxanonanoyl)amide (PFPE), and a combination of FOTS and PFPE at various mass ratios (2.0:0.4, 1.6:0.8, 1.2:1.2, 0.8:1.6, 0.4:2.0) (g)) on the performance of sodium bicarbonate-based UDPEA. The results indicate that using FOTS or PFPE alone improves the water and oil contact angles, but still fails to meet the required hydrophobicity and oleophobicity standards, and it also reduces the flowability and fire-extinguishing capability. A combination of FOTS and PFPE at the 1:2 ratio yields the best performance, with the water and oil contact angles of 145.169° and 143.542°, respectively, the lowest flowability index (0.224), minimal extinguishing concentration and time (14.183 g/m3 and 1.976 s, respectively), which is only 52.7% and 68.3% of those of the unmodified UDPEA's (26.927 g/m3 and 2.893 s), and the longest anti-reignition time (68.5 s). In addition, the fire-extinguishing mechanisms (chemical inhibition and physical heat absorption) and anti-reignition mechanisms of the modified UDPEA (with the FOTS to PFPE ratio of 1:2) were revealed. This research aims to design an eco-friendly, high-performance UDPEA as an effective substitute for Halon extinguishing agents. These findings can provide valuable insights for evaluating and selecting aviation fire-extinguishing agents.

Functional dry powders of connexin-containing extracellular vesicles

Extracellular vesicles (EVs) have emerged as a promising drug delivery system. Connectosomes are a specialized type of EVs that contain connexins in their membranes. Connexin is a surface transmembrane protein that forms connexin hemichannels. When a connexin hemichannel on a connectosome docks with another connexin hemichannel of a target cell, they form a gap junction that allows direct intracellular delivery of therapeutic cargos from within the connectosome to the cytoplasm of the recipient cell. In the present study, we tested the feasibility of converting connectosomes into dry powders by (thin-film) freeze-drying to enable their potential storage in temperatures higher than the recommended −80 °C, while maintaining their activity. Connectosomes were isolated from a genetically engineered HeLa cell line that overexpressing connexin-43 subunit protein tagged with red fluorescence protein. To facilitate the testing of the function of the connectosomes, they were loaded with calcein green dye. Calcein green-loaded connectosomes were thin-film freeze-dried with trehalose alone or trehalose and a polyvinylpyrrolidone polymer as lyoprotectant(s) to produce amorphous powders with high glass transition temperatures (>100 °C). Thin-film freeze-drying did not significantly change the morphology and structure of the connectosomes, nor their particle size distribution. Based on data from confocal microscopy, flow cytometry, and fluorescence spectrometry, the connexin hemichannels in the connectosomes reconstituted from the thin-film freeze-dried powder remained functional, allowing the passage of calcein green through the hemichannels and the release of the calcein green from the connectosomes when the channels were opened by chelating calcium in the reconstituted medium. The function of connectosomes was assessed after one month storage at different temperatures. The connexin hemichannels in connectosomes in liquid lost their function when stored at −19.5 ± 2.2 °C or 6.0 ± 0.5 °C for a month, while those in dry powder form remained functional under the same storage conditions. Finally, using doxorubicin-loaded connectosomes, we showed that the connectosomes reconstituted from thin-film freeze-dried powder remained pharmacologically active. These findings demonstrate that (thin-film) freeze-drying represents a viable method to prepare stable and functional powders of EVs that contain connexins in their membranes.

The Efficacy of Budesonide-formoterol in Patients with Acute Attacks of Mild-to-moderate Bronchial Asthma: An Observational Study

To assess the impact of budesonide-formoterol on pulmonary ventilation function and prognosis in patients with mild-to-moderate acute exacerbations of bronchial asthma. A retrospective analysis was conducted on clinical data from 232 patients with acute exacerbations of bronchial asthma. These patients were divided into 2 groups based on their treatment: a control group (n=104) receiving budesonide dry powder inhalation and an observation group (n=107) receiving budesonide-formoterol dry powder inhalation. Clinical efficacy and safety indicators were compared. The results showed that the total treatment effectiveness rate in the observation group was significantly higher than that in the control group. Following treatment, the observation group exhibited significantly higher scores in the Asthma Quality of Life Questionnaire (AQLQ), as well as improved levels of forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF), compared to the control group. Moreover, levels of tumor necrosis factor-alpha, interleukin-6, and C-reactive protein were significantly lower in the observation group. The incidence of adverse reactions between groups was comparable. Based on these findings, the application of budesonide-formoterol demonstrated significant effectiveness in patients with mild-to-moderate acute exacerbations of bronchial asthma. The combination therapy led to improved clinical outcomes, including enhanced pulmonary ventilation function and reduced inflammatory markers. Importantly, the safety profile of budesonide-formoterol was comparable to that of budesonide monotherapy. These results highlight the potential benefits of using budesonide-formoterol as an alternative treatment option for patients experiencing acute exacerbations of mild-to-moderate bronchial asthma.

Different Carriers for Use in Dry Powder Inhalers: Characteristics of Their Particles.

In contemporary times, there has been a rise in the utilization of dry powder inhalers (DPIs) in the management of pulmonary and systemic diseases. These devices underwent a swift advancement in terms of both the equipment utilized and the formulation process. In this review, the carrier physicochemical characteristics that influence DPI performance are discussed, focusing its shape, morphology, size distribution, texture, aerodynamic diameter, density, moisture, adhesive and detachment forces between particles, fine carrier particles, and dry powder aerosolization. To promote the deposition of the active principal ingredient deep within the pulmonary system, advancements have been made in enhancing these factors and surface properties through the application of novel technologies that encompass particle engineering. So far, the most used carrier is lactose showing some advantages and disadvantages, but other substances and systems are being studied with the intention of replacing it. The final objective of this review is to analyze the physicochemical and mechanical characteristics of the different carriers or new delivery systems used in DPI formulations, whether already on the market or still under investigation. [Figure: see text].

LC[sbnd]HRMS-based metabolomics on Acalypha indica with different altitude and antioxidant activity

Achalypha indica is a weed that has medicinal properties. This study aims to determine the metabolite profile and evaluate the antioxidant activity of A. indica from areas with different altitudes, Tuban (20 to 50 masl; TBN), Banyuwangi (60 to 90 masl; BB), Magetan (300 to 600 masl; MGT), and Malang (500 to 800 masl; MLG). The ethanol extract of A. indica was analyzed for total phenolics and antioxidant activity. Separation and identification of samples were carried out using liquid chromatography-high-resolution mass spectrometry (LCHRMS), then classified by Principal Component Analysis (PCA). The total phenol value ranged from 6.83 to 10.67 mg GAE /g of dry powder, with an antioxidant IC50 of 86.09 to 118.96 µg/mL. LCHRMS successfully identified 83 metabolites. PCA analysis was able to clearly distinguish each sample based on the altitude of the growing location with a total variance value reaching 82 % (PC-1: 57 %, and PC-2: 25 %). Heat map analysis that observes variations in metabolite composition in each sample shows an increase in the content of flavonoid compounds in the lowlands under certain geographical conditions. Therefore, the height of the growing location has a significant influence on the metabolite profile and antioxidant activity. These findings are very important for assessing the quality, safety, and efficacy of medicinal plant raw materials.

Dry Powder Inhaler Use in Primary School Aged Children with Asthma: A Systematic Review

ObjectiveAsthma is the most common chronic disease in children. Dry powder inhalers (DPI) are effective for medication delivery in adults and adolescents, and provide a lower environmental footprint and more portability when compared to metered dose inhaler (MDI) with spacer. They require specific technique, and it is necessary to ascertain whether they can be used in younger age groups. We aimed to assess evidence regarding whether primary school aged (5–11 years) children can use DPI with adequate technique both during stable and acute asthma.DesignOvid MEDLINE, Embase and PubMed were searched for studies assessing DPI use in children aged 5–11 years with asthma or wheeze. Results of studies were synthesised by study design and outcome measure.ResultsThirty-eight studies were identified for analysis. These were analysed in three groups: (1) 25 studies assessing children's ability to use DPI by peak inspiratory flow measurement, (2) 10 studies assessing children's ability to use DPI by physician assessment, and (3) three studies measuring efficacy of DPI compared to gold standard (MDI with spacer). Five studies included children during acute exacerbations.ConclusionThe majority of primary school aged children have the ability to use a DPI with adequate training, support and practice. Some younger children may have difficulties, and clinician assessment and ongoing review is crucial in determining which children are likely to benefit from a DPI. Consistent correct use and adherence remains a challenge, but this is also an issue with MDI plus spacer and does not appear to be significantly worse with DPI. Evidence of the use of DPI during acute illness is limited, and more studies are required in this setting.

Ferulic acid-g-tamarind gum/guar gum based in situ gel-forming powders as wound dressings

The current research endeavour aimed to synthesize ferulic acid grafted tamarind gum/guar gum (FA-g-TG/GG) based powders as wound dressings, which could form in situ gels upon contact with wound exudates. In this context, variable amounts of FA were initially grafted with TG via the Steglich esterification reaction protocol and the resulting conjugates were subsequently amalgamated with GG and lyophilized to produce dry powders (F-1 – –F-3) with average particle size within 5.10–5.54 μm and average angle of repose ∼30°. These powders were structurally characterized with 1H NMR, FTIR, DSC, TGA, XRD and SEM analyses. Pristine TG, FA-g-TG and FA-g-TG/GG powders (F-2) revealed their distinct morphological structures and variable negative zeta potential values (−11.06 mV–25.50 mV). Among various formulation (F-1–F-3), F-2 demonstrated an acceptable powder-to-gel conversion time (within 20 min), suitable water vapour transmission rates (WVTR, 2564.94 ± 32.47 g/m2/day) and excellent water retention abilities and swelling profiles (4559.00 ± 41.57 %) in wound fluid. The powders were cytocompatible and conferred antioxidant activities. The powders also displayed fibroblast cell proliferation, migration and adhesion properties, implying their wound-healing potentials. Thus, the developed in situ gel-forming powders could be employed as promising dressings for wound management.

Quality by Design in Pulmonary Drug Delivery: A Review on Dry Powder Inhaler Development, Nanotherapy Approaches, and Regulatory Considerations.

Dry powder inhalers (DPIs) are state-of-the-art pulmonary drug delivery systems. This article explores the transformative impact of nanotechnology on DPIs, emphasizing the Quality Target Product Profile (QTPP) with a focus on aerodynamic performance and particle characteristics. It navigates global regulatory frameworks, underscoring the need for safety and efficacy standards. Additionally, it highlights the emerging field of nanoparticulate dry powder inhalers, showcasing their potential to enhance targeted drug delivery in respiratory medicine. This concise overview is a valuable resource for researchers, physicians, and pharmaceutical developers, providing insights into the development and commercialization of advanced inhalation systems.

Comparisons between In-Check DIAL® and PF810® in evaluation and training inspiratory capacity for using dry powder inhalers

BackgroundDry powder inhalers (DPIs) rely on both internal resistance and patients’ inspiratory capacity for effective operation. Optimal inspiratory technique is crucial for DPI users. This study assessed the accuracy and repeatability of two available devices, PF810® and In-Check DIAL®, and analyzed their measurement errors and consistency in detecting inspiratory capacity.MethodsThe accuracy and repeatability of peak inspiratory flow (PIF) and forced inspiratory vital capacity (FIVC) against various internal resistances of the two devices were assessed using standard waveforms generated by a breathing simulator. The agreement of PIF measurements between the two devices in healthy volunteers and chronic obstructive pulmonary disease (COPD) patients was analyzed with the intraclass correlation coefficient and Bland–Altman graphical analysis.ResultsPF810® showed great accuracy and repeatability in measuring PIF, except for square waveforms at the lowest flow rate (20 L/min). In-Check DIAL® exhibited poor accuracy against high resistance levels. In scenarios with no resistance, In-Check DIAL® had significantly smaller measurement errors than PF810®, but larger errors against high resistance levels. The two devices showed excellent agreement (ICC > 0.80, P < 0.05), except for healthy volunteers against medium to high resistance (R3-R5) where the ICC was insignificant. Bland–Altman plots indicated small disagreements between the two devices for both healthy volunteers and COPD patients.ConclusionsIn-Check DIAL® exhibited poor accuracy and larger measurement errors than PF810® when detecting PIFs against higher internal resistances. However, its good performance against lower internal resistances, along with its cost-effectiveness and convenience made it appropriate for primary care. PF810® showed good accuracy and repeatability and could detect additional parameters of inspiratory capacity beyond PIF, though required further studies to confirm its clinical benefits.

Development of a New Dry Powder Aerosol Synthetic Lung Surfactant Product for Neonatal Respiratory Distress Syndrome (RDS) – Part I: In Vitro Testing and Characterization

PurposeImproving the deep lung delivery of aerosol surfactant therapy (AST) with a dry powder formulation may enable significant reductions in dose while providing improved efficacy. The objective of Part I of this two-part study was to present the development of a new dry powder aerosol synthetic lung surfactant (SLS) product and to characterize performance based on aerosol formation and realistic in vitro airway testing leading to aerosol delivery recommendations for subsequent in vivo animal model experiments.MethodsA new micrometer-sized SLS excipient enhanced growth (EEG) dry powder formulation was produced via spray drying and aerosolized using a positive-pressure air-jet dry powder inhaler (DPI) intended for aerosol delivery directly to intubated infants with respiratory distress syndrome (RDS) or infant-size test animals.ResultsThe best-case design (D2) of the air-jet DPI was capable of high emitted dose (> 80% of loaded) and formed a < 2 µm mass median aerodynamic diameter (MMAD) aerosol, but was limited to ≤ 20 mg mass loadings. Testing with a realistic in vitro rabbit model indicated that over half of the loaded dose could penetrate into the lower lung regions. Using the characterization data, a dose delivery protocol was designed in which a 60 mg total loaded dose would be administered and deliver an approximate lung dose of 14.7–17.7 mg phospholipids/kg with a total aerosol delivery period < 5 min.ConclusionsA high-efficiency aerosol SLS product was designed and tested that may enable an order of magnitude reduction in administered phospholipid dose, and provide rapid aerosol administration to infants with RDS.

Choice justification of the fruit and berry raw materials to produce pasta of the functional purpose

Abstract The article presents the results of the chemical composition study of the whortleberry berries (Vaccinium vitis-idaea L.) and common sea buckthorn (Hippophae rhamnoides L), naturally growing in the forest-steppe zone of the Krasnoyarsk territory. It is shown that the studied biomass contains a rich mineral-vitamin complex, represented by vitamins A, C, group B and P-active substances, as well as magnesium, iron, phosphorus. This circumstance makes it possible to recommend the indicated vegetable raw materials in the production of functional food products. Based on the use of dry powders of the meal of the berries of these plants, a recipe for functional pasta has been developed. It has been established that the introduction of 5 to 10 wt.% of dry powders of the whortleberry berries and sea buckthorn into the classic pasta dough recipe makes the organoleptic properties and nutritional value of the finished product optimal. Consumption of 100 g of the product provides the body with, mg: ascorbic acid - 10.5-21.0; P-active substances - 1.5-6.4; magnesium - 18-30; phosphorus - 9-18; iron - 0.4-1.4. The expert evaluation of organoleptic indicators revealed compliance with regulatory requirements, while the experts noted a pleasant, harmonious taste of the product.

Climate change from the Asia-Pacific perspective: What an allergist needs to know and do.

Allergic diseases such as asthma, atopic dermatitis, and food allergies are a burgeoning health challenge in the Asia-Pacific region. Compounding this, the region has become increasingly susceptible to the impacts of climate change. The region has weathered extreme precipitation, intense heat waves, and dust storms over the recent decades. While the effects of environmental and genetic factors on allergic diseases are well understood, prevailing gaps in understanding the complex interactions between climate change and these factors remain. We aim to provide insights into the various pathways by which climate change influences allergic diseases in the Asia-Pacific population. We outline practical steps that allergists can take to reduce the carbon footprint of their practice on both a systemic and patient-specific level. We recommend that allergists optimize disease control to reduce the resources required for each patient's care, which contributes to reducing greenhouse gas emissions. We encourage the responsible prescription of metered dose inhalers by promoting the switch to dry powder inhalers for certain patients, at each clinician's discretion. We also recommend the utilization of virtual consultations to reduce patient travel while ensuring that evidence-based guidelines for rational allergy management are closely adhered to. Finally, eliminating unnecessary testing and medications will also reduce greenhouse gas emissions in many areas of medical care.

Thoughtful prescription of inhaled medication has the potential to reduce inhaler-related greenhouse gas emissions by 85%

IntroductionBoth physicians and patients are increasingly aware of the environmental impacts of medication. The shift of treatment paradigm towards MART-treatment (Maintenance and Reliever Therapy) in asthma affects the treatment-related emissions....

Pulmonary Inhalation of Biotherapeutics: A Systematic Approach to Understanding the Effects of Atomisation Gas Flow Rate on Particle Physiochemical Properties and Retained Bioactivity.

The identification of spray-drying processing parameters capable of producing particles suitable for pulmonary inhalation with retained bioactivity underpins the development of inhalable biotherapeutics. Effective delivery of biopharmaceuticals via pulmonary delivery routes such as dry powder inhalation (DPI) requires developing techniques that engineer particles to well-defined target profiles while simultaneously minimising protein denaturation. This study examines the simultaneous effects of atomisation gas flow rate on particle properties and retained bioactivity for the model biopharmaceutical lysozyme. The results show that optimising the interplay between atomisation gas flow rate and excipient concentration enables the production of free-flowing powder with retained bioactivity approaching 100%, moisture content below 4%, and D50 < 4 µm, at yields exceeding 50%. The developed methodologies inform the future design of protein-specific spray-drying parameters for inhalable biotherapeutics.

Changes in Peak Inspiratory Flow After Acute Bronchodilation: An Observational Study of Patients with Stable Chronic Obstructive Pulmonary Disease.

Introduction: Identifying factors influencing peak inspiratory flow (PIF) is essential for aerosol drug delivery in stable patients with chronic obstructive pulmonary disease. While a minimum PIF for dry powder inhalers (DPIs) is established, acute bronchodilator (BD) effects on PIF remain unknown. Materials and Methods: An inspiratory flow meter (In-Check™ DIAL) was used to measure PIF in stable patients during a 24-week observational cross-sectional study. Additionally, bronchodilator responsiveness (BDR) was determined using the In-Check DIAL device and spirometry. Patients received four puffs of albuterol, and pre- and post-BD PIF, forced expiratory volume in one second (FEV1), and forced vital capacity were measured. Sixty-three patients completed acute BDR data collection from July 31, 2019, to November 9, 2021. Primary endpoints were pre- and post-BD spirometry and PIF. Statistical analyses included PIF correlations with FEV1. BD change was assessed according to inhaler resistance and sex (subgroup analysis). Results: Median patient age was 64.8 years, 85.7% were non-Hispanic White, and 57.1% were female. The median increase in absolute PIF (In-Check DIAL) was 5.0 L/min, and the % PIF change was 8.9%. With albuterol, 57.1% experienced a PIF BD change >5.0%, whereas 49.2% experienced a change >10.0%. Similarly, 55.6% experienced an FEV1 BD change >5.0% and 28.6% had a >10.0% FEV1 BD change with albuterol. PIF was weakly correlated with FEV1 BD change (absolute; % PIF; r = 0.28 [p = 0.02]; r = 0.21 [p = 0.11]). Pre- and post-BD median PIF were 75.5 and 83.5 L/min for low-to-medium-resistance DPI and 45.0 and 52.0 L/min for high-resistance, respectively. The median increases in pre- and post-BD PIF were 9.0 L/min in males and 4.5 L/min in females. In contrast to when using the In-Check DIAL device, we observed no consistent bronchodilatory effects on PIF measured by spirometry. Conclusions: Using the In-Check DIAL device, ∼50% of patients experienced >10% PIF increase after acute BD, potentially enhancing medication lung deposition. Further research is required to understand PIF's impact on medication delivery. ClinicalTrials.gov Identifier: NCT04168775.

Prevalence and Management of Chronic Obstructive Pulmonary Disease in the Gulf Countries with a Focus on Inhaled Pharmacotherapy.

Background: Chronic obstructive pulmonary disease (COPD) is a preventable, progressive disease and the third leading cause of death worldwide. The epidemiological data of COPD from Gulf countries are very limited, as it remains underdiagnosed and underestimated. Risk factors for COPD include tobacco cigarette smoking, water pipe smoking (Shisha), exposure to air pollutants, occupational dusts, fumes, and chemicals. Inadequate treatment of COPD leads to worsening of disease. The 2024 GOLD guidelines recommend use of inhaled bronchodilators, corticosteroids, and adjunct therapies for treatment and management of COPD patients based on an individual assessment of the severity of symptoms and risk of exacerbations. This article reviews COPD pharmacotherapy in the Gulf countries and explores the role of nebulization in the management of COPD in this region. Methods: To review the COPD pharmacotherapy in the Gulf Countries, literature search was conducted using PubMed, Medline, Cochrane Systematic Reviews, and Google Scholar databases (before December 2022), using search terms such as COPD, nebulization, inhalers/inhalation, aerosols, and Gulf countries. Relevant articles from the reference list of identified studies were reviewed. Consensus statements, expert opinion, and other published review articles were included. Results: In the Gulf countries, pressurized metered-dose inhalers (pMDIs), dry powder inhalers (DPIs), soft mist inhalers, and nebulizers are used for drug delivery to COPD patients. pMDIs and DPIs are most prone to errors in technique and other common device handling errors. Nebulization is another mode of inhalation drug delivery, which is beneficial in certain patient populations such as the elderly and patients with cognitive impairment, motor or neuromuscular disorders, and other comorbidities. Conclusion: There is no major difference between Gulf countries and rest of the world in the approach to management of COPD. Nebulizers should be considered for patients who have difficulties in accessing or using MDIs and DPIs, irrespective of geographical location.

Inhalable dry powder nano-formulations: advancing lung disease therapy-a review

Inhalable dry powder nano-formulations: advancing lung disease therapy-a review

Dandelion inspired microparticles with highly efficient drug delivery to deep lung

Active pharmaceutical ingredient (API) embedded dry powder for inhalation (AeDPI) shows higher drug loading and delivery dose for directly treating various lung infections. Inspired by the dandelion, we propose a novel kind of AeDPI microparticle structure fabricated by spray freeze drying technology, which would potentially enhance the alveoli deposition efficiency. When inhaling, such microparticles are expected to be easily broken-up into fragments containing API that acts as ‘seed’ and could be delivered to alveoli aided by the low density ‘pappus’ composed of excipient. Herein, itraconazole (ITZ), a first-line drug for treating pulmonary aspergillosis, was selected as model API. TPGS, an amphiphilic surfactant, was used to achieve stable primary ITZ nanocrystal (INc) suspensions for spray freeze drying. A series of microparticles were prepared, and the dandelion-like structure was successfully achieved. The effects of feed liquid compositions and freezing parameters on the microparticle size, morphology, surface energy, crystal properties and in vitro aerosol performance were systematically investigated. The optimal sample (SF(-50)D-INc7Leu3-2) in one-way experiment showed the highest fine particle fraction of ∼ 68.96 % and extra fine particle fraction of ∼ 36.87 %, equivalently ∼ 4.60 mg and ∼ 2.46 mg could reach the lung and alveoli, respectively, when inhaling 10 mg dry powders. The response surface methodology (RSM) analysis provided the optimized design space for fabricating microparticles with higher deep lung deposition performance. This study demonstrates the advantages of AeDPI microparticle with dandelion-like structure on promoting the delivery efficiency of high-dose drug to the deep lung.