Dry Powder Research Articles

Drying kinetics of CeO2-ZrO2 ceramic powders under microwave heating based on a thin-layer drying model

Volume change of ZrO2 during martensitic phase transformation can cause cracking of material and limit the application of ZrO2.Agglomeration of CeO2-ZrO2 ceramic powders can be effectively reduced by choosing the correct drying method. Microwave drying of CeO2-ZrO2 powder can effectively reduce the cracking of zirconia materials and improve powder uniformity. Microwave heating is used to dry CeO2-ZrO2 ceramic powders, and results demonstrate that Modified Page fits experimental data rather well. FT-IR spectra revealed a remarkable decrease in the intensity of the -OH bond's stretching vibration peak, and H-O-H bond's bending vibration. Utilizing Fick's second law, the diffusion coefficient of water molecules in CeO2-ZrO2 ceramic powders with a mass of 20 g and a moisture content of 6.6 % is calculated to be 5.820 × 10−15 m2/s under microwave power of 400 W. Experimental results prove that microwave heating has low activation energy, improves drying efficiency, and realizes fast and efficient drying.

Optimization of /locel 101 and Amylum as /illers in Sambiloto (Andrographis paniculata (Burm.f.) Nees.) Capsules /ormulation

Sambiloto (Andrographis paniculata (Burm.f.) Nees.) is an herbal plant that is beneficial for health due to its main chemical component, andrographolide. Sambiloto can be formulated into capsules to make it more practical and comfortable for consumption, mask the bitter taste, and guarantee dosage accuracy. This research aimed to determine the optimal concentration of Flocel 101 and amylum as capsule fillers to achieve the best physical properties of Sambiloto extract capsules. The study was conducted experimentally using 5 (five) formulas (F1, F2, F3, F4, and F5) with various concentrations of Flocel 101 and amylum. A series of tests were conducted on the physical properties of the capsule powder: organoleptic tests, water content, flowability, disintegration time, and average capsule weight. Additionally, quality control was performed by checking for microbial contamination through total plate count (TPC) and yeast and mold count (YMC) tests. The results of this research indicated that the F1 formula provided the best physical properties and met the requirements, with the appearance of a greenish-gray dry powder, water content of 6.88%, flow rate of 20 g/s, disintegration time of 15.5 minutes, average weight of 0.55 g, TPC 250 cfu/g, and YMC <10 cfu/g.

Venture capitalist directors and managerial incentives

We examine the effect of board members with venture capital experience (VC directors) on executive incentives at non-venture-backed public firms. VC directors serving on the compensation committee are associated with greater CEO risk-taking incentives (vega) and pay-for-performance sensitivity (delta). These effects are more substantial if VC directors are from highly reputable VC firms. Using the change of direct flight availability to VC hub cities caused by major airline mergers and annual estimates of VC dry powder per industry as instruments, we show that these results are causal. In addition, VC directors are more focused on growth performance goals in CEO compensation contracts. We also document that prior finding of greater research intensity and innovation when VC directors serve on boards of public firms is partly explained by stronger CEO incentives instilled by such directors. Lastly, we find that having VC directors on nominating and/or governance committees is associated with a higher likelihood of forced CEO turnover.

Antibiotic-loaded nanoparticles for the treatment of intracellular methicillin-resistant Staphylococcus Aureus infections: In vitro and in vivo efficacy of a novel antibiotic

Antimicrobial resistance is considered one of the biggest threats to public health worldwide. Methicillin-resistant S. aureus is the causative agent of a number of infections and lung colonization in people suffering from cystic fibrosis. Moreover, a growing body of evidence links the microbiome to the development of cancer, as well as to the success of the treatment. In this view, the development of novel antibiotics is of critical importance, and SV7, a novel antibiotic active against MRSA at low concentrations, represents a promising candidate. However, the low aqueous solubility of SV7 hampers its therapeutic translation. In this study, SV7 was encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) to improve the solubility profile, to ensure sustained release and eventually support deposition in the airways. Furthermore, PLGA NPs were formulated as dry powder to extend their shelf-life and were shown to efficiently target intracellular infections. After identifying a formulation with suitable physico-chemical characteristics, SV7-loaded NPs were investigated in vitro in terms of inhibitory activity against MRSA, and their safety profile in lung epithelial cells. Subsequently, the activity against MRSA intracellular infections was investigated in a co-culture model of MRSA and macrophages. To test the translatability of our findings, SV7-loaded NPs were tested in vivo in a Galleria mellonella infection model. In conclusion, SV7-loaded NPs showed a safe profile and efficient inhibitory activity against MRSA at low concentrations. Furthermore, their activity against intracellular infections was confirmed, and was retained in vivo, rendering them a promising candidate for treatment of MRSA lung infections.

Synergistic cryoprotective effect of deaeration and polysorbate 80 on IgG denaturation during thin-film freeze-drying

Polysorbate 80 (PS80) is employed as a cryoprotectant in biotherapeutic formulations to preserve biologics from denaturation during the freezing process. However, excessive quantities of PS80 can lead to stickiness in dry powder, thereby reducing production yields and altering the physical and aerodynamic characteristics of the powder. Additionally, degradation byproducts of PS80 pose a risk of destabilizing proteins in therapeutic formulations. Our study reveals the synergistic cryoprotective effect of combining deaeration with PS80. PS80 plays a protective role by competitively binding to ice/water and air/water interfaces, as well as binding directly to IgG molecules. Deaeration increases the cryoprotective effect of PS80 by reducing the surface area of air microbubbles, thereby reducing the required amount of PS80 for surface coverage and limiting available adsorption sites for IgG molecules, which allows the decrease in the necessary concentration of PS80 required to minimize IgG denaturation during the thin-film freeze-drying (TFFD) process. Even at a low concentration of 0.0025 % w/v, PS80 prevents the aggregation of IgG during the freezing step of TFFD but does not eliminate IgG denaturation during the drying step. PS80 concentrations ranging from 0.0025 % to 0.0400 % w/v exhibit no impact on the specific surface area (SSA) and aerodynamic properties (i.e., fine particle fraction (FPF), mass median aerodynamic diameter (MMAD)) of IgG dry powders. These IgG TFFD powders exhibit a fine particle fraction exceeding 70 % and a median mass aerodynamic diameter of approximately 2.3–2.5 μm, with an SSA of around 20 m2/g.

Sustained Release Microparticles Inhalation for Tuberculosis Treatment: Present Issues and Prospects

Mycobacterium tuberculosis, the primary cause of tuberculosis in humans, is a transmissible airborne disease. One of the most significant medical advances of the 20th century was the development of medications to cure tuberculosis. It makes sense to create strategies for administering antitubercular medications orally, or through the respiratory system. The pulmonary route lowers systemic toxicity, necessitates a lower dose, and has instantaneous drug release, first pass hepatic metabolism, and side effects. Presently, the most prevalent patterns in study aim to offer the optimal dry powders in the appropriate fraction for inhalation, which can release the medication before it is eliminated through natural mechanisms.

Redispersible dry powders containing nanoencapsulated curcumin increase its antioxidant activity

The present study aimed to develop redispersible spray-dried powders containing curcumin-loaded Eudragit® L100 nanocapsules and evaluate their physicochemical properties and antioxidant potential. The spray drying process showed a yield of over 85%, low residual moisture content (<2%), and all the physicochemical characteristics of the nanocapsules were recovered after the aqueous redispersion of the dry powders. In addition to the dry powders, the following samples were also analyzed: pure curcumin, pure lactose, and curcumin-lactose mix. In TGA and DSC analysis, all samples were thermostable and exhibited no chemical interactions with each other. In FTIR analysis, the nanostructured powder system showed functional groups of the precursors (curcumin and lactose), confirming the effectiveness in the preparation of the nanostructured material. In the evaluation of the free radical scavenging activity of DPPH•, the dry powder containing nanoencapsulated curcumin showed antioxidant activity approximately six times higher than free curcumin. Therefore, spray drying of nanoencapsulated curcumin made it possible to obtain a dry powder with homogeneous aqueous redispersion, as well as promoting the potentiation of the antioxidant activity of curcumin.

Preparation and characterization of NaAl(OH)2CO3 dry powder extinguishing agent with environmentally friendly and extinguishing efficiency

Preparation and characterization of NaAl(OH)2CO3 dry powder extinguishing agent with environmentally friendly and extinguishing efficiency

Synergistic effect of magnesium stearate and fine lactose in improving aerosolization performance of fluticasone propionate in dry powder formulation

Magnesium stearate (MgSt) and lactose fines are often used as ternary components in carrier-based dry powder inhalers (DPIs) to improve fine particle fraction (FPF), but whether they act synergistically to improve aerosolization performance of DPI formulations is currently less studied. In addition, the applicability of utilizing powder rheological parameters to predict the FPF needs to be further verified. Thus, in this study, using fluticasone propionate (FP) as a model drug, effect of lactose fines addition in 0.5% MgSt containing DPI formulations on their powder and aerodynamic properties was explored. Influence of MgSt and fines mixing order on the DPIs performance was also investigated. The results showed that addition of lactose fines (1–10%) in 0.5% MgSt containing formulations could further improve flowability and enhance adhesion of the mixtures, and they could act synergistically to improve FPF. Moreover, the presence of 0.5% MgSt can greatly reduce the amount of lactose fines required to achieve the comparable FPF. The mixing order can affect distribution of MgSt on the carrier surface, with higher FPF noted when MgSt was mixed with carrier first, followed by lactose fines. A good linear relationship between powder rheological parameters such as basic flowability energy (BFE), Permeability and FPF was disclosed. In conclusion, in FP based DPIs, MgSt and lactose fines act synergistically to enhance FPF by tuning powder characteristics. Good flowability (27.39%) and strong adhesion (72.61%) contributed to the enhanced drug deposition in the lung.

Development of a proliposomal pretomanid dry powder inhaler as a novel alternative approach for combating pulmonary tuberculosis

Multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) continue as public health concerns. Inhaled drug therapy for TB has substantial benefits in combating the causal agent of TB (Mycobacterium tuberculosis). Pretomanid is a promising candidate in an optional combined regimen for XDR-TB. Pretomanid has demonstrated high potency against M. tuberculosis in both the active and latent phases. Conventional spray drying was used to formulate pretomanid as dry powder inhalers (DPIs) for deep lung delivery using a proliposomal system with a trehalose coarse excipient to enhance the drug solubility. Co-spray drying with L-leucine protected hygroscopic trehalose in formulations and improved powder aerosolization. Higher amounts of L-leucine (40–50 % w/w) resulted in the formation of mesoporous particles with high percentages of drug content and entrapment efficiency. The aerosolized powders demonstrated both geometric and median aerodynamic diameters < 5 µm with > 90 % emitted dose and > 50 % fine particle fraction. Upon reconstitution in simulated physiological fluid, the proliposomes completely converted to liposomes, exhibiting suitable particle sizes (130–300 nm) with stable colloids and improving drug solubility, leading to higher drug dissolution compared to the drug alone. Inhalable pretomanid showed higher antimycobacterial activity than pretomanid alone. The formulations were safe for all broncho-epithelial cell lines and alveolar macrophages, thus indicating their potential suitability for DPIs targeting pulmonary TB.

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.