Spray Freeze Drying Research Articles

Optimization of ultrasonic-assisted debittering of Ganoderma lucidum using response surface methodology, characterization, and evaluation of antioxidant activity.

Ganoderma lucidum (G. lucidum) has gained increasing attention as a potential health care product and food source. However, the bitter taste of G. lucidum has limited its development and utilization for the food industry. The response surface methodology was employed to optimize the inclusion conditions for the debittering of G. lucidum. The effects of 2-hydroxypropyl-β-cyclodextrin concentration (12-14 g/mL), ultrasound temperature (20-40°C and host-guest ratio (1:1-2:1) on response variables were studied. The physical characteristics of inclusion complexes prepared through spray drying and freeze drying were analyzed. The antioxidant activity of the different treated samples was subsequently investigated. Study results showed that, in comparison to the control group, the inclusion solution displayed a significantly enhanced taste profile under optimal processing conditions, exhibiting an 80.74% reduction in bitterness value. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (NMR) studies indicated the successful formation of inclusion compounds. The moisture content and bulk density of spray-dried powder were found to be significantly superior to those of freeze-dried powder (p<0.05). In comparison to the diluted solution, the inclusion liquid demonstrated a 20.27%, 30.01% and 36.55% increase in ferric ion reducing antioxidant power (FRAP), hydroxyl radical scavenging and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging respectively. Further, the DPPH clearance of microencapsulated powder was not significantly different from that of tocopherol at a concentration of 25 mg/mL. In summary, the study provides theoretical basis and methodological guidance to eliminate the bitterness of G. lucidum, and therefore provide potential options to the use of G. lucidum as a food source.

Fabrication of Uniform Melatonin Microparticles Potentially for Nasal Delivery: A Comparison of Spray Drying and Spray Freeze Drying.

Insomnia is a major health concern, and melatonin (MLT) is key for initiating sleep. Delivering MLT nasally can enhance brain bioavailability by targeting the olfactory region. This study aimed to fabricate MLT embedded microparticles for nasal delivery. MLT-cyclodextrin (CD) derivatives complex microparticles (MCCMPs) were fabricated by spray drying and spray freeze drying MLT and CD derivative solutions. Phase solubility and 1H-1H ROSEY NMR analysis assessed MLT-CD assembly. The effects of formulation compositions and process parameters on microparticle structural attributes were investigated. The in vitro nasal release and deposition performances were evaluated by a modified paddle-over-disk apparatus and 3D-printed nasal cavity cast, respectively. Sodium sulphobutylether-β-cyclodextrin (SBE-β-CD) exhibited the best complexation ability with MLT, with the indole structure of MLT included in its cavity. Spray dried MCCMPs showed dense structure with high density, while the spray freeze dried counterpart showed the brittle and porous structure with low density. Despite the porous structure may promote the release rate of spray freeze dried samples, the high hydrophilicity of the CD derivative overshadows this advantage. Samples prepared by spray drying not only exhibited rapid release rates but also could deposit more effectively in the olfactory region, as they avoid breakage due to their higher mechanical strength. The optimal sample showed ~ 86.70% of the MLT released at 20min and ~ 10.57% of the deposition fraction in the olfactory region. This work compares MCCMPs fabricated by spray drying and spray freeze drying, providing the optimal formulation and process combinations.

Effects of spray drying and freeze drying on the protein profile of whey protein concentrate.

Whey protein concentrate (WPC) is consumed for its high protein content. The structure and biological functionality of whey proteins in WPC powders may be affected by the drying technique applied. However, the specific impact of spray drying and freeze drying on the overall protein profile of whey protein derived from sweet whey streams at scale is unknown. Herein, we examine the effects of commercial-scale freeze drying and spray drying on WPC to determine which method better preserves bioactive whey proteins, with the goal of helping the dairy industry create high-value products that meet the growing consumer demand for functional dairy products. WPCs were produced from pasteurized liquid whey using either a commercial spray dryer or freeze dryer. A variety of analytical techniques, including enzyme-linked immunosorbent assay, polyacrylamide gel electrophoresis, and bottom-up proteomics using liquid chromatography-tandem mass spectroscopy were used to identify, quantify, and compare the retention of bioactive proteins in WPC before and after spray drying and freeze drying. In addition, the extent of denaturation was studied via solubility testing, differential scanning calorimetry, and hydrophobicity assessment. There was little to no difference in the retention or denaturation of key bioactive proteins between spray-dried and freeze-dried WPC powders. There was a higher percentage of select Maillard modifications in freeze-dried and spray-dried powders than in the control. The lack of significant differences between spray drying and freeze drying identified herein indicates that freeze drying does not meaningfully improve retention of bioactive proteins compared with spray drying when performed after multiple pasteurization steps. PRACTICAL APPLICATION: This study aimed to provide insight into the impacts of spray drying versus freeze drying on whey proteins. Overall, our results indicate that for commercial dairy processing that involves multiple rounds of pasteurization, freeze drying does not meaningfully improve the retention of bioactive proteins compared with spray drying. These findings may help the food and dairy industry make informed decisions regarding the processing of its whey protein products to optimize nutritional value.

Microencapsulation of total saponins from stem and leaf of Panax notoginseng by freeze and spray drying: Process optimization, physicochemical properties, structure, antioxidant activity, and stability.

Ginsenosides are the primary active substance in ginseng plants and have a variety of benefits. However, its light and heat stability are weak and easy to decompose. This study used gum arabic (GA) and maltodextrin (MD) as wall materials, and 1% Tween 80 was used as emulsifier. Response surface methodology was used to optimize the preparation process of total saponins in the stems-leaves of Panax notoginseng (SLPNs) (SSLP) microcapsules by spray drying and freeze drying techniques. Under optimal process conditions, the two microcapsules have better solubility and lower moisture content (MC). The color of spray-dried SSLP microcapsules was greener and bluer, and the color was brighter. In morphology, the spray-dried SSLP microcapsules were spherical with a slightly shrunk surface, whereas the freeze-dried ones were lamellar and porous. The two microcapsules have strong stability under different storage conditions and in vitro gastrointestinal digestion simulation. In addition, both microcapsules and free SSLP contained multiple ginsenosides. At the same time, both microcapsules had good free radical scavenging ability. These results indicate that the microencapsulation technology could improve the stability and bioavailability of SSLP, which is expected to provide a reference for the intensive processing of the SLPN. PRACTICAL APPLICATION: After microencapsulation, the stem and leaf extract of Panax notoginseng improved its stability and taste, which laid a foundation for making more nutritious and better tasting food of the stem and leaf of P. notoginseng.

Stable and inhalable powder formulation of mRNA-LNPs using pH-modified spray-freeze drying

A powder formulation for mucosal administration of mRNA-encapsulated lipid nanoparticles (mRNA-LNPs) is expected to be useful for respiratory diseases. Although freeze-drying is widely used to obtain solid formulations of mRNA-LNPs, highly hydrosoluble cryoprotectants, such as sucrose are necessary. However, sucrose is not a suitable excipient for inhalation powders because of its hygroscopic and deliquescence properties. Spray freeze-drying (SFD) is a method to produce inhalable powder formulation. In this study, we prepared inhalable powder formulations of mRNA-LNPs without deliquescence excipients using pH-modified SFD, which strengthens the interaction between mRNA and ionizable lipids of LNPs by acidic pH modifier, leading to retention of the encapsulated structure of mRNA-LNPs even after SFD. Powdered mRNA-LNPs were suitable for inhalation, and mRNA was encapsulated in LNPs after SFD. The mRNA encapsulation efficiency and mRNA transfection efficiency of pH-modified SFD-mediated powdered mRNA-LNPs were higher than those of conventional SFD, although they were significantly lower than those of liquid intact mRNA-LNPs. However, after long-term storage, the powdered formulation of the mRNA-LNPs exhibited higher mRNA transfection efficiency than liquid mRNA-LNP. Powdered mRNA-LNPs also exerted their function in air–liquid interface cultivation and in vivo intratracheal administration. Collectively, the powder formulation of mRNA-LNPs especially prepared by SFD is expected to be applied for dry powder inhalers.

Improved viability of probiotics by co-encapsulation of wheat germ oil under storage and gastrointestinal conditions: Effects of drying methods and wall composition

To improve the viability of probiotics during food storage and gastrointestinal digestion, this study developed solid microcapsules co-loaded with probiotics and wheat germ oil using W1/O/W2 emulsion pre-encapsulation, followed by spray drying (SD), freeze drying (FD) and spray freeze drying (SFD), respectively. The effects of drying methods and wall materials on the microstructure, physicochemical properties, storage stability, and gastrointestinal tolerability were highlighted. Firstly, all samples showed high encapsulation efficiency for probiotics (86%–99.2%) and wheat germ oil (72%–85%), low moisture content (2.8%–5.3%) and hygroscopicity (6.3%–11.6%), and wall materials exhibited structural stability during the drying process. The results of viable cell counts indicated that SFD caused more damage to bacterial cells than the other two drying methods, as evidenced by the total death of encapsulated probiotics within 90 days. In contrast, SD and FD encapsulated probiotics remained at 8.8–9.9 log CFU/g after 150 days of storage at 4 °C and 25 °C. Furthermore, the viability of probiotics in the co-encapsulated and pectin-added microcapsules was significantly enhanced in storage stability and simulated gastrointestinal digestion tests. Based on the above results, it was suggested that the co-encapsulation strategy of combining the W1/O/W2 structure and SD or FD to prepare microencapsulated powders can obtain probiotic products with high activity and high stability. Meanwhile, composite wall material (whey protein isolate and pectin) could enhance probiotics' protective effect and colonic targeted release behavior. In conclusion, the current research provides a valuable reference for the application of probiotics and functional oils in the food industry.

Enrichment of White Chocolate with Microencapsulated β-Carotene: Impact on Quality Characteristics and β-Carotene Stability during Storage.

This study developed functional white chocolate enriched with free (WC-F) and encapsulated β-carotene using whey protein isolate (WPI) and pullulan (PUL) blends through spray drying (WC-SP), freeze drying (WC-LP), and coaxial electrospinning (WC-EL). The thermal properties, rheological properties, hardness, and color of the chocolates were evaluated, and the stability of β-carotene was monitored over 4 months at 25 °C. No significant differences were found in melting profile temperatures among samples; however, WC-LP and WC-EL exhibited higher melting energies (30.88 J/g and 16.00 J/g) compared to the control (12.42 J/g). WC-F and WC-SP showed rheological behaviors similar to those of the control, while WC-LP and WC-EL displayed altered flow characteristics. Hardness was unaffected in WC-F and WC-SP (7.77 N/mm2 and 9.36 N/mm2), increased slightly in WC-LP (10.28 N/mm2), and decreased significantly in WC-EL (5.89 N/mm2). Over storage, melting point, rheological parameters, and hardness increased slightly, while color parameters decreased. β-carotene degradation followed a first-order reaction model, with degradation rate constants (k) of 0.0066 day-1 for WC-SP, 0.0094 day-1 for WC-LP, and 0.0080 day-1 for WC-EL, compared to 0.0164 day-1 for WC-F. WC-SP provided the best β-carotene retention, extending the half-life period by 2 times compared to WC-F (126.04 days vs. 61.95 days). Practical implications: The findings suggest that WC-SP, with its superior β-carotene stability, is particularly suitable for the development of functional confectionery products with extended shelf life, offering potential benefits in industrial applications where product stability is crucial. Future research directions: Further studies could explore the incorporation of additional bioactive compounds in white chocolate using similar encapsulation methods, as well as consumer acceptance and sensory evaluation of these enriched products.

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.

The survival and stability of Lactobacillus rhamnosus GG as affected by particle formation during spray drying and spray-freeze drying

Droplets of the same composition can be transformed into particles with varying properties by different drying methods and conditions. In this study, Lactobacillus rhamnosus GG (LGG) encapsulated in trehalose matrix was produced using a micro-fluidic jet spray dryer and a micro-fluidic spray-freeze tower, respectively, with 10 and 30 wt% protectant. The spray-freeze-dried microparticles between 139.9 and 152.9 μm showed porous morphology with airy structure, contrasting the spherical, smooth, and dense microparticles produced by spray drying with relatively small size (75.1–110.4 μm). The encapsulated cells formed clusters in spray-dried microparticles. The high-solids protectant of 30 wt% resulted in high survivals of LGG (35.40% and 49.58%) with minimal cellular membrane damages and relatively high metabolic activity in both spray drying and spray-freeze drying. Compared to the 10% spray-dried particles with a survival of 30.04%, a lower survival of 12.56% and more substantial cellular injuries were observed for the 10% spray-freeze-dried particles, reflecting the damage to cells from water crystallization during freezing. Both spray-freeze-dried samples exhibited much better stability during storage and in vitro digestion than the spray-dried samples, which could be linked to the low residual moisture after dehydration. Considering stresses experienced by LGG cells, spray-freeze drying offers a promising alternative to freeze drying for producing active lactic-acid-bacteria powders, whereas the intensity of stresses under the tested spray-drying conditions remained challenging for achieving the maximal retention of the viability and functionality of the bacteria.

Dry Powder Inhaler Formulation of Lactobacillus rhamnosus GG Targeting Pseudomonas aeruginosa Infection in Bronchiectasis Maintenance Therapy.

The inhaled delivery of lactic acid bacteria (LAB) probiotics has been demonstrated to exert therapeutic benefits to the lungs due to LAB's immunomodulatory activities. The development of inhaled probiotics formulation, however, is in its nascent stage limited to nebulized LAB. We developed a dry powder inhaler (DPI) formulation of lactobacillus rhamnosus GG (LGG) intended for bronchiectasis maintenance therapy by spray freeze drying (SFD). The optimal DPI formulation (i.e., LGG: mannitol: lactose: leucine = 35: 45: 15: 5 wt.%) was determined based on the aerosolization efficiency (86% emitted dose and 26% respirable fraction) and LGG cell viability post-SFD (7 log CFU/mL per mg powder). The optimal DPI formulation was evaluated and compared to lyophilized naked LGG by its (1) adhesion capacity and cytotoxicity to human lung epithelium cells (i.e., A549 and 16HBE14o- cells) as well as its (2) effectiveness in inhibiting the growth and adhesion of Pseudomonas aeruginosa to lung cells. The optimal DPI of LGG exhibited similar non-cytotoxicity and adhesion capacity to lung cells to naked LGG. The DPI of LGG also inhibited the growth and adhesion of P. aeruginosa to the lung cells as effectively as the naked LGG. The present work established the feasibility of delivering the LAB probiotic by the DPI platform without adversely affecting LGG's anti-pseudomonal activities.

Tailored Sugar-Mediated Porous Particle Structures for Improved Dispersion of Drug Nanoparticles in Spray-Freeze-Drying.

We fabricated porous particles incorporating sugars (mannitol, sucrose, or dextran) and fenofibrate nanoparticles (FNPs) by using spray-freeze-drying (SFD). The type of sugar significantly influenced the pore architecture of the resulting SFD particles. Rapid freezing of droplets containing dextran produced ice encapsulation within a dextran matrix, forming porous dextran particles. In the presence of FNPs, the particle size (approximately 4 μm) and pore volume (0.3 cm3/g) of SFD dextran were barely affected. In contrast, SFD particles derived from mannitol and sucrose exhibited denser structures with a lower pore volume than dextran. SFD mannitol incorporating FNPs produced porous structures. FNPs containing surfactant and polymer, which reduced surface tension and increased viscosity, promoted the formation of small droplets with a polymeric structure and porous particles with a relatively sharp size distribution with a median around 5 μm. FNPs were uniformly distributed in SFD dextran, which featured large pore structures, whereas in SFD mannitol, the Raman signal of FNPs was more broadly distributed across the powder samples. Both morphologies contributed to enhancing the FNP dispersibility within a redispersed suspension of SFD particles. FNPs in SFD mannitol and dextran matrices maintained their particle size distribution from before SFD, showing no aggregation upon redispersion. Dextran formed a highly porous network irrespective of the presence of FNPs, whereas mannitol tended to alter the particle attributes upon FNP inclusion. In conclusion, SFD particles derived from dextran and mannitol might help to increase FNP dispersibility by increasing the formation of porous architectures.

Aquivion-Based Spray Freeze-Dried Composite Materials for the Cascade Production of γ-Valerolactone.

The development of multifunctional catalysts is a necessary step to effectively carry out one-pot cascade reactions, such as that from furfural to γ-valerolactone. This research effort faces the challenge posed by the intrinsic limit of how many kinds of catalytic sites a single material can bear. In this work, the application of Spray-Freeze Drying (SFD) as a synthetic technique for the preparation of a wide range of innovative composite multi-functional catalysts is reported. Herein we show that by the proper combination of Aquivion as a highly active Brønsted acid catalyst and metal oxides as both support materials and Lewis acids (LAS) enable to achieve highly unique efficient and effective dual acid composite catalysts that are able to carry out the cascade reaction from furfural to γ-valerolactone. The dual catalytic system comprised of Aq/ZrO2 with 30 % polymer content prepared via spray-freeze drying exhibited GVL yields of 25 % after only 2 h at 180 °C and a remarkably high productivity of 4470 μmolGVL gCat -1 h-1, one of the highest reported results. Mechanistic studies based on experimental and advanced characterisation and spectroscopic techniques, such as, SEM, TEM, 15N MAS NMR and 19F MAS NMR indicate that activity arises from the proper tuning of BAS/LAS (Brønsted Acid Site/Lewis Acid Site) acidic properties.

Abnormally High Graphitic Crystallization of Cellulose Nanocrystals.

Cellulose nanocrystals (CNCs) are currently of great interest for many applications, such as energy storage and nanocomposites, because of their natural abundance. A number of carbonization studies have reported abnormal graphitization behavior of CNCs, although cellulose is generally known as a precursor for hard carbon (nongraphitizable carbon). Herein, we report a spray-freeze-drying (SFD) method for CNCs and a subsequent carbonization study to ascertain the difference in the structural development between the amorphous and crystalline phases. The morphological observation by high-resolution transmission electron microscopy of the carbonized SFD-CNC clearly shows that the amorphous and crystalline phases of CNC are attributed to the formation of hard and soft carbon, respectively. The results of a reactive molecular dynamics (RMD) study also show that the amorphous cellulose phase leads to the formation of fewer carbon ring structures, indicative of hard carbon. In contrast, the pristine crystalline cellulose phase has a higher density and thermal stability, resulting in limited molecular relaxation and the formation of a highly crystalline graphitic structure (soft carbon).

Dry powder inhalation containing muco-inert ciprofloxacin and colistin co-loaded liposomes for pulmonary P. Aeruginosa biofilm eradication

Pseudomonas aeruginosa (PA), a predominant pathogen in lung infections, poses significant challenges due to its biofilm formation, which is the primary cause of chronic and recalcitrant pulmonary infections. Bacteria within these biofilms exhibit heightened resistance to antibiotics compared to their planktonic counterparts, and their secreted toxins exacerbate lung infections. Diverging from traditional antibacterial therapy for biofilm eradication, this study introduces a novel dry powder inhalation containing muco-inert ciprofloxacin and colistin co-encapsulated liposomes (Cipro-Col-Lips) prepared using ultrasonic spray freeze drying (USFD) technique. This USFD dry powder is designed to efficiently deliver muco-inert Cipro-Col-Lips to the lungs. Once deposited, the liposomes rapidly diffuse into the airway mucus, reaching the biofilm sites. The muco-inert Cipro-Col-Lips neutralize the biofilm-secreted toxins and simultaneously trigger the release of their therapeutic payload, exerting a synergistic antibiofilm effect. Our results demonstrated that the optimal USFD liposomal dry powder formulation exhibited satisfactory in vitro aerosol performance in terms of fine particle fraction (FPF) of 44.44 ± 0.78 %, mass median aerodynamic diameter (MMAD) of 4.27 ± 0.21 μm, and emitted dose (ED) of 99.31 ± 3.31 %. The muco-inert Cipro-Col-Lips effectively penetrate the airway mucus and accumulate at the biofilm site, neutralizing toxins and safeguarding lung cells. The triggered release of ciprofloxacin and colistin works synergistically to reduce the biofilm’s antibiotic resistance, impede the development of antibiotic resistance, and eliminate 99.99 % of biofilm-embedded bacteria, including persister bacteria. Using a PA-beads induced biofilm-associated lung infection mouse model, the in vivo efficacy of this liposomal dry powder aerosol was tested, and the results demonstrated that this liposomal dry powder aerosol achieved a 99.7 % reduction in bacterial colonization, and significantly mitigated inflammation and pulmonary fibrosis. The USFD dry powder inhalation containing muco-inert Cipro-Col-Lips emerges as a promising therapeutic strategy for treating PA biofilm-associated lung infections.

Microencapsulation of fish oil by spray drying, spray freeze-drying, freeze-drying, and microwave freeze-drying: Microcapsule characterization and storage stability.

The objective of this paper was to evaluate the effect of spray drying (SD), spray freeze-drying (SFD), freeze-drying (FD), and microwave freeze-drying (MFD) on the characteristics of fish oil (FO) microcapsules. The physicochemical properties, morphology, fatty acid composition, and stability of the microcapsules were analyzed. The encapsulation efficiencies of microcapsules dried by SD, SFD, FD, and MFD were 86.98%, 77.79%, 63.29%, and 57.89%, respectively. SD microcapsules exhibited superior properties in terms of effective loading capacity, color, and flowability. Conversely, SFD microcapsules demonstrated improved solubility. Microencapsulation positively affected the thermal stability of FO, but the content of unsaturated fatty acids decreased. The findings from the storage experiment indicated that the oxidative stability of SD fish oil microcapsules was marginally lower compared to microcapsules produced through three alternative drying techniques, all of which were based on the FD concept. The comparison of various drying methods and their effects on the quality of FO microcapsules offers valuable insights that can serve as a foundation for the industrial production of high-quality microcapsules.

Fast dissolving tablet

Fast dissolving tablets have emerged as a popular dosage form, particularly beneficial for pediatric and geriatric patients facing challenges such as dysphagia or hand tremors. These tablets dissolve quickly in saliva without needing water, enhancing compliance and effectiveness of therapy. They offer advantages like easy portability, accurate dosing, and improved bioavailability. Various technologies, including spray drying and melt granulation, have been developed for their manufacturing. This review provides comprehensive information on fast dissolving tablets, covering their definition, advantages, limitations, challenges, and available formulations. The design of an oral drug delivery system prioritizes convenience in administration and improved patient compliance, making it the preferred route of drug delivery despite certain drawbacks. Over the last decade, there has been a growing demand for Fast Disintegrating Tablets (FDTS), turning this field into a rapidly expanding area within the pharmaceutical industry. The formulation’s popularity and effectiveness have led to the development of various FDT technologies. These technologies aim to achieve rapid tablet disintegration and mouth dissolution within five seconds, eliminating the need for chewing or water intake. This characteristic is particularly advantageous for populations such as pediatrics, geriatrics, and patients facing difficulties in swallowing conventional tablets and capsules. The formulation of an easily administrable dosage form, considering challenges like swallowing difficulties and low patient compliance, has driven the creation of orally disintegrating tablets. Traditional preparation methods include spray drying, freeze drying, direct compression, molding, and sublimation. In addition, new technologies have been devised to enhance the production of orodispersible tablets.

Encapsulation of black pepper oleoresin by applying different wall materials with spray- or freeze-drying techniques and quality determination

Black pepper oleoresin was processed to powder for handling convenience in logistics and applications. Various wall materials (gum Arabic, modified starch, maltodextrins, or blends of them) and drying techniques (spray drying or freeze drying) were applied. The main objective was to determine the proper method for producing black pepper oleoresin microcapsules. The results demonstrated that the suitable oleoresin concentration for feed emulsion formulation was 15% (w/w) concerning the wall material weight, while gum Arabic was deemed as the most suitable wall material of those investigated, based on feed emulsion stability and encapsulation efficiency. Freeze-drying had greater values for powder recovery and total piperine content; nonetheless, spray-drying was recommended, based on its higher encapsulation efficiency, product solubility, product stability during storage, and lower costs. Encapsulated oleoresin powders had a slower piperine retention percentage reduction than raw black pepper powder and free oleoresin during storage.

Effect and application of spray drying and freeze drying on characterization of walnut oil microcapsules

In the current study, a walnut oil (WO) emulsion was prepared with WO as the core material and sodium caseinate and maltodextrin as the wall materials. The effects of spray drying (SD) and freeze drying (FD) on the structure and quality of WO microcapsules were compared, and the role of WO microcapsules as a substitute for commercial creamer in coffee was investigated. The results demonstrated that the WO microcapsules prepared by the SD method had dense microstructure, spherical particles, no oil drop aggregation, small particle size, good fluidity, an embedding rate of up to 93.60%, an unsaturated fatty acid content of 87.00%, and no significant difference in thermal stability or stability of the restored emulsion compared with FD. The freeze-dried WO microcapsules have irregular structure, porous surface structure, high oil content on the surface, 76.84% embedding rate, some accumulation of droplets, large grain size, and poor fluidity. The electronic nose and electronic tongue results reveal that the microcapsules prepared by the two methods have similar flavor when applied to coffee. The spray-dried WO microcapsules are prepared with a flavor closer to that of commercial creams. In summary, microcapsules prepared by SD are superior to FD and are promising for industrial production; further, the nondairy creamer based on WO has great potential for coffee application.

Nasal delivery of encapsulated recombinant ACE2 as a prophylactic drug for SARS-CoV-2

Angiotensin-converting enzyme 2 (ACE2) is responsible for cell fusion with SARS-CoV viruses. ACE2 is contained in different areas of the human body, including the nasal cavity, which is considered the main entrance for different types of airborne viruses. We took advantage of the roles of ACE2 and the nasal cavity in SARS-CoV-2 replication and transmission to develop a nasal dry powder. Recombinant ACE2 (rhACE2), after a proper encapsulation achieved via spray freeze drying, shows a binding efficiency with spike proteins of SARS-CoV-2 higher than 77 % at quantities lower than 5 µg/ml. Once delivered to the nose, encapsulated rhACE2 led to viability and permeability of RPMI 2650 cells of at least 90.20 ± 0.67 % and 47.96 ± 4.46 %, respectively, for concentrations lower than 1 mg/ml. These results were validated using nasal dry powder containing rhACE2 to prevent or treat infections derived from SARS-CoV-2.

Development of favipiravir dry powders for intranasal delivery: An integrated cocrystal and particle engineering approach via spray freeze drying

The therapeutic potential of pharmaceutical cocrystals in intranasal applications remains largely unexplored despite progressive advancements in cocrystal research. We present the application of spray freeze drying (SFD) in successful fabrication of a favipiravir-pyridinecarboxamide cocrystal nasal powder formulation for potential treatment of broad-spectrum antiviral infections. Preliminary screening via mechanochemistry revealed that favipiravir (FAV) can cocrystallize with isonicotinamide (INA), but not nicotinamide (NCT) and picolinamide (PIC) notwithstanding their structural similarity. The cocrystal formation was characterized by differential scanning calorimetry, Fourier-transform infrared spectroscopy, and unit cell determination through Rietveld refinement of powder X-ray analysis. FAV-INA crystalized in a monoclinic space group P21/c with a unit cell volume of 1223.54(3) Å3, accommodating one FAV molecule and one INA molecule in the asymmetric unit. The cocrystal was further reproduced as intranasal dry powders by SFD, of which the morphology, particle size, in vitro drug release, and nasal deposition were assessed. The non-porous flake shaped FAV-INA powders exhibited a mean particle size of 19.79 ± 2.61 μm, rendering its suitability for intranasal delivery. Compared with raw FAV, FAV-INA displayed a 3-fold higher cumulative fraction of drug permeated in Franz diffusion cells at 45 min (p = 0.001). Dose fraction of FAV-INA deposited in the nasal fraction of a customized 3D-printed nasal cast reached over 80 %, whereas the fine particle fraction remained below 6 % at a flow rate of 15 L/min, suggesting high nasal deposition whilst minimal lung deposition. FAV-INA was safe in RPMI 2650 nasal and SH-SY5Y neuroblastoma cells without any in vitro cytotoxicity observed. This study demonstrated that combining the merits of cocrystallization and particle engineering via SFD can propel the development of advanced dry powder formulations for intranasal drug delivery.