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Comparison of Flowability and Sinterability Among Different Binder Jetting Feedstock Powders: Nanopowder, Micropowder, and Granulated Powder

Wenchao Du, Guanxiong Miao, Zhijian Pei, Chao Ma

Abstract

Feedstock powders used in binder jetting additive manufacturing include nanopowder, micropowder, and granulated powder. Two important characteristics of the feedstock powders are flowability and sinterability. This paper aims to compare the flowability and sinterability of different feedstock powders. Three powders were compared: nanopowder (with a particle size of ∼100 nm), micropowder (with a particle size of 70 μm), and granulated powder (with a granule size of ∼70 μm) made from the nanopowder by spray freeze drying. Flowability metrics employed included apparent density (AD), tap density (TD), volumetric flow rate (VFR), mass flow rate (MFR), Hausner ratio (HR), Carr index (CI), and repose angle (RA). Sinterability metrics employed included sintered bulk density (SBD), volumetric shrinkage (VS), and densification ratio (DR). Results show that the granulated powder has a higher flowability than the nanopowder and a higher sinterability than the micropowder. Moreover, different flowability metric values of the granulated powder are close to those of the micropowder, indicating that these two powers have a comparably high flowability. Similarly, different sinterability metric values of the granulated powder are close to those of the nanopowder, indicating that these two powders have a comparably high sinterability.

Control some foodborne pathogens, contaminated bacteria and fungi by fabrication calyx cape gooseberry (Physalis peruviana L.) nanoparticles

Hany Mohamed YEHIA, Manal Fawzy ELKHADRAGY, Rania Ibrahim SHEBL, Abdulrahman Hamad Al-MASOUD, Mohamed Ferkry Serag EL-DIN

Abstract

We studied the effect of the calyx of cape gooseberry nanoparticles manufactured by a novel technique. There are several methods, such as jet mill, spray freezing, supercritical anti-solvent technique (SAS), and high-pressure homogenization, available for the production of drug micro/nanoparticles to improve drug solubility. Anti-solvent precipitation is also used to prepare micro- and nanosized particles to explain their effects on different foodborne pathogens, contaminated bacteria, and some fungi. Results indicated that nanoparticles of the cape gooseberry calyx contained higher antioxidant activity than that found in the normal calyx, seed, and juice. While studying the effect of cape gooseberry calyx nanoparticles on microorganisms, it was found that the zone of inhibition was highly positive against Bacillus cereus, B. subtilis, Staphylococcus aureus, Clostridium perfringens, and Salmonella typhimurium compared to that of the normal cape gooseberry calyx. All species of molds, including Mucor sp., Aspergillus niger, Penicillium sp., and Alternaria sp., and yeasts like Saccharomyces cerevisiae and Rhodotorula glutinis were affected by nanoparticles of the cape gooseberry calyx compared to those of the normal calyx.

Keywords

calyx; cape gooseberry; nanoparticles; antioxidant activities; microorganisms

Emerging Technologies and Coating Materials for Improved Probiotication in Food Products: a Review

Sourav Misra, Pooja Pandey, Chandrakant Genu Dalbhagat, Hari Niwas Mishra

Abstract

From the past few decades, consumers’ demand for probiotic-based functional and healthy food products is rising exponentially. Encapsulation is an emerging field to protect probiotics from unfavorable conditions and to deliver probiotics at the target place while maintaining the controlled release in the colon. Probiotics have been encapsulated for decades using different encapsulation methods to maintain their viability during processing, storage, and digestion and to give health benefits. This review focuses on novel microencapsulation techniques of probiotic bacteria including vacuum drying, microwave drying, spray freeze drying, fluidized bed drying, impinging aerosol technology, hybridization system, ultrasonication with their recent advancement, and characteristics of the commonly used polymers have been briefly discussed. Other than novel techniques, characterization of microcapsules along with their mechanism of release and stability have shown great interest recently in developing novel functional food products with synergetic effects, especially in COVID-19 outbreak. A thorough discussion of novel processing technologies and applications in food products with the incorporation of recent research works is the novelty and highlight of this review paper.

Keywords

Drying; Functional foods; Microencapsulation; Packaging condition; Probiotics; Storage.

Synthesized nano particles of glimepiride via spray freezing into cryogenic liquid: characterization, antidiabetic activity, and bioavailability

Dalia A Gaber, Abdulrahman S Alhuwaymili, Hessah S Alhawas, Alhnouf A Almutiri, Amal M Alsubaiyel, Siham A Abdoun, Reem A Almutairi

Abstract

The aim of this work was to formulate glimepiride (class II drug) which is characterized by low solubility and high permeability as nanostructured particles using a cryogenic technique with an aid of water-soluble polymer to improve its aqueous solubility and hence its bioavailability. 27 formula of glimepiride nano size particles were prepared by a spray freezing into cryogenic liquid (SCFL) using poly vinyl pyrrolidone K-30 (PVP K-30); that three drug polymer ratio (1:1, 1:2, and 1:3), with three different volumes of feeding solution (50, 100, 150 mL), at three flow rates (10, 20, and 30 mL/min). The prepared formulations were evaluated for production yield, particle size, zeta potential, drug content, release rate, in vivo hypoglycemic activity, and bioavailability. All prepared formulations showed high production yield and drug content ranged between 91.1 ± 3.4% and 94.3 ± 1.8% and 95.1 ± 2.8% and 97.1 ± 2.5%, respectively. The mean particles size was ranged between 280 ± 62 nm and 520 ± 30 nm. The results of in vitro release study revealed significant enhancement in the solubility of prepared formulations compared with the pure drug. It was found that optimal formula showed a significant reduction in blood glucose levels in diabetic rats, and 1.79-fold enhancements in oral bioavailability compared with market tablets. Nanoparticle prepared by SCFL method is an encouraging formula for improving the solubility and the bioavailability of glimepiride.

Keywords

Antidiabetic; Glimepiride; bioavailability; cryogenic; nano size.

Ultrasonic spray freeze-drying of sucrose and mannitol-based formulations: Impact of the atomization conditions on the particle morphology and drying performance

Merve B. Adali, Antonello Barresi, Gianluca Boccardo, Giorgia Montalbano, Roberto Pisano

Abstract

Spray freeze-drying is an emerging manufacturing technology that offers many advantages, including long-term stability, consistent particle size distribution, and enhanced bioavailability. However, its implementation on an industrial scale is still hampered by several technical problems relating to the design of the equipment and the selection of appropriate operating conditions. This study aims to clarify the relationship between the atomization conditions (atomizing power, feed flow rate, and viscosity) and the characteristics of the lyophilized powder (particle size distribution and morphology) for two model products (sucrose- and mannitol-based formulations). Independently of the formulation, the particle morphology only depended on its solid content, while the average particle size increased with the feed flow rate and viscosity. Lastly, the specific surface area of the lyophilized powder varied with the initial solid content and the type of excipient as well, with mannitol-based particles having the highest specific surface area.

Keywords

Spray freeze-drying, freeze-drying, ultrasonic atomizer, particle morphology, particle size distribution, porous particles

Spray freeze drying to solidify Nanosuspension of Cefixime into inhalable microparticles

Samaneh Alaei, Elham Ghasemian, Alireza Vatanara

Abstract

Size reduction to a nanoscale is a relatively new approach to overcome solubility and bioavailability issues of many drugs such as cefixime (CFX). However, nanoparticles and specifically nanosuspensions are prone to many instabilities like aggregation and sedimentation. One of the main solutions is transforming liquid nanosuspension into dry powder. In this study, cefixime (CFX) nanosuspension was co-spray dried in the presence of different carriers (lactose, mannitol and sorbitol) in 3 ratios of nanoparticles (NPs)/carriers (1, 1.5 and 4 (w/w)). Physicochemical properties of the obtained powders were assessed in terms of particle size, morphology, thermal behavior, flowability, dissolution profile and aggregation over 6 months. Co-processing of NPs resulted in the formation of partially spherical particles with deeply wrinkled surfaces in the sizes ranging from 3.61 to 12.18 μm. Flowability showed improvement of all microparticles and thermal analysis demonstrated an amorphous state. Results suggest that among carriers, sorbitol based microparticles had the same dissolution profile as the initial NPs (29-fold increase in maximum solubility compared to unprocessed CFX) and could preserve reconstituted NPs’ size efficiently after storage. This shows the feasibility of using sorbitol as a promising carrier for spray drying of nanosuspensions which was mostly used for co-processing of solid lipid nanoparticles, proteins and peptides before.

Optimization of spray freeze drying parameters for spark plasma sintering of transparent MgAl2O4 spinel

Aref Basiri, Amir Hossein, Nassajpour-Esfahani, Mohammad Reza, Haftbaradaran-Esfahani, Amir Alhaji, Ali Shafyei

Abstract

Magnesium aluminate spinel (MgAl2O4) is considered as one of the most important spinels possessing desirable mechanical properties, with a wide range of applications at high temperatures. Powder granulation by spray freeze drying can lead to better powder flow and distribution in the mold, resulting in a specimen with high green density and strength. Accordingly, this study aimed at investigating the influential parameters on the granulation process of spinel powders via the spray freezing drying method. At first, spinel powders with various weight percents of 20, 25, 30, 35 and 50, and PVA binders with 0, 1, 2 and 8 wt% were investigated to prepare the optimal solution. Finally, the granules were sintered using the SPS method. The obtained bodies were tested by X-ray diffraction, SEM, FE-SEM, Viscosity and UV–Vis. The results showed that the optimal amount of the binder to obtain uniform granules in this process was 3%. Also, 35 wt% of solid loads represented the optimum amount for slurries, forming granules with the size range of 10–50 μm. By powder granulation, density experienced an increase of about 20%, leading to the growth of more than 15% in the in-line transmission for the IR range.

Keywords

Magnesium aluminate spinel, Spray freeze drying, Granulation, Spark plasma sintering

Polyphosphates as an effective vehicle for delivery of bioavailable nanoparticulate iron(III)

Shiyang Li, Tengjiao Guo, Wei Guo, Xuan Cui, Mingyong Zeng, Haohao Wu

Abstract

Polyphosphates are widely used food additives with the potential to increase iron bioavailability but chemical nature of their soluble complexes with iron remains largely unknown. Here, pyrophosphate, tripolyphosphate, hexametaphosphate and ∼25-chain-length polyphosphate solubilized 896, 896, 1120 and 1344 mg Fe(III) per g, respectively, at neutral pH by mediating the formation of highly-negatively-charged ferric hydroxide-polyphosphate nanoparticles (PolyP-FeONPs). PolyP-FeONPs displayed fading yellow color with increasing initial dissolved P/Fe ratio ((P/Fe)init) and decreasing polyphosphate length due to rising proportion of Fe(III)-phosphate bonds, and specifically, pyrophosphate resulted colorless PolyP-FeONPs at (P/Fe)init ≥ 4. PolyP-FeONPs had weak pro-oxidant activity in glyceryl trilinoleate emulsion and good colloidal stability under spray/freeze-drying and gastrointestinal conditions. Serum iron kinetics in rats revealed sustained iron release and ∼170% iron bioavailability of oral PolyP-FeONPs relative to FeSO4. Calcein-fluorescence-quenching assay in polarized Caco-2 cells unveiled divalent-metal-transporter-1-independent and macropinocytosis-dependent iron uptake from PolyP-FeONPs. This study helps develop food-compatible, highly-bioavailable and sustained-release iron preparations.

Keywords

Caco-2 cells; Endocytosis; Nanoparticles; Polyphosphates; Relative iron availability

Identification of Stability Constraints in the Particle Engineering of an Inhaled Monoclonal Antibody Dried Powder

Ashlee D Brunaugh, Li Ding, Tian Wu, Michael Schneider, Ryan Khalaf, Hugh D C Smyth

Abstract

Monoclonal antibody (mAb) based therapies may provide a valuable new treatment modality for acute and chronic lung diseases, including asthma, respiratory infections, and lung cancer. Currently mAbs are delivered via systemic administration routes, but direct delivery to the lungs via the inhaled route could provide higher concentrations at the site of disease and reduced off-target effects. Though lyophilized mAbs may be reconstituted and delivered to the lungs using nebulizers, dry powder inhalers provide a more patient-friendly delivery method based upon their fast administration time and portability. However, particle engineering processes required to prepare respirable dried powders for DPI delivery involve multiple potential stressors for mAbs, which have not been fully explored. In this study, a systematic examination of various aspects of the particle engineering process (atomization, freezing, drying, and storage) was performed to further understand their impact on mAb structure and aggregation. Using anti-streptavidin IgG1 as a model mAb, atomization settings were optimized using a design of experiments approach to elucidate the relationship between feed flow rate, formulation solid content, and atomization airflow rate and protein structural changes and aggregation. The optimized atomization conditions were then applied to spray drying and spray freezing drying particle engineering processes to determine the effects of freezing and drying on IgG1 stability and aerosol performance of the powders. IgG1 was found to be particularly susceptible to degradation induced by the expansive air-ice interface generated by spray freeze drying and this process also produced powders that exhibited decreased storage stability. This study further delineates the design space for manufacturing of respirable biologic therapies and is intended to serve as a roadmap for future development work.

Keywords

Monoclonal antibody; Particle engineering; Pulmonary drug delivery; Spray drying; Spray freeze drying; Stability

Spray-freeze-dried inhalable composite microparticles containing nanoparticles of combinational drugs for potential treatment of lung infections caused by Pseudomonas aeruginosa

Shihui Yu, XiaohuiPu, Maizbha Uddin Ahmed, Heidi H.Yu, Tarun Tejasvi Mutukuri, Jian Li, Qi Tony Zhou

Abstract

The multi-drug resistance of Pseudomonas aeruginosa is an overwhelming cause of terminal and persistent lung infections in cystic fibrosis (CF) patients. Antimicrobial synergy has been shown for colistin and ivacaftor, and our study designed a relatively high drug-loading dry powder inhaler formulation containing nanoparticles of ivacaftor and colistin. The ivacaftor-colistin nanosuspensions (Iva-Col-NPs) were prepared by the anti-solvent method with different stabilizers. Based on the aggregation data, the formulation 7 (F7) with DSPG-PEG-OMe as the stabilizer was selected for further studies. The F7 consisted of ivacaftor, colistin and DSPG-PEG-OMe with a mass ratio of 1:1:1. The F7 powder formulation was developed using the ultrasonic spray-freeze-drying method and exhibited a rough surface with relatively high fine particle fraction values of 61.4 ± 3.4% for ivacaftor and 63.3 ± 3.3% for colistin, as well as superior emitted dose of 97.8 ± 0.3% for ivacaftor and 97.6 ± 0.5% for colistin. The F7 showed very significant dissolution improvement for poorly water soluble ivacaftor than the physical mixture. Incorporating two drugs in a single microparticle with synchronized dissolution and superior aerosol performance will maximize the synergy and bioactivity of those two drugs. Minimal cytotoxicity in Calu-3 human lung epithelial cells and enhanced antimicrobial activity against colistin-resistant P. aeruginosa suggested that our formulation has potential to improve the treatment of CF patients with lung infections.

Keywords

Colistin, Ivacaftor, Cystic fibrosis, Pseudomonas aeruginosa, Dry powder inhaler, In vitro dissolution