Laboratory-scale Spray Dryer Research Articles

Characterization and effect of optimized spray-drying conditions on spray-dried coriander essential oil

Coriander (Coriandrum sativum L.) essential oil (CEO) has many beneficial features, including antimicrobial and antifungal properties along with good aroma. It also has an important role in food processing and preservation. However, CEO is highly volatile and sensitive to external factors (heat, light and oxygen), as well as susceptible to lipid oxidation due to environmental and general processing conditions. This limits water solubility, making it difficult to incorporate CEO into aqueous food matrices, which further limits their industrial application. Spray-drying encapsulation may prevent CEO oxidation, increase CEO oxidative stability and improve their physicochemical properties. In this study, spray-dried CEO (SDCEO) was prepared using a mini laboratory-scale spray-dryer and the processing conditions were optimized. The SDCEO were characterized in respect to free fatty acids (FFA), peroxide values (PV), fatty acid (FA) profiles, Fourier-transform infrared spectroscopy (FTIR) and physical morphology by scanning electron microscopy (SEM). Results indicated that the maximum value of FFA, PV, fatty acid composition (including petroselinic, linoleic and oleic acids) in SDCEO were observed at the following spray-drying conditions: an inlet-air temperature (IAT) of 140 °C, needle speed (NS) of 2 s and the wall-material (WM) at 25%. The minimum values were observed at an IAT of 180 °C, NS of 4 s and WM of 30%. Analysis of variance and the interaction effects of independent factors showed that IAT and WM significantly positively influenced the response for good oxidative stability. Thus, SDCEO is likely to be used as a natural active ingredient in the food processing, cosmetic, nutraceutical and pharmaceutical industries with high stability, and may be stored for a long time without evaporation or oxidation.

The preparation, characterization, and application of porous core–shell composite particles produced with laboratory-scale spray dryer

Objective To prepare porous core–shell composite particles (PCPs) in order to improve the flowability and compactibility of powder materials for direct compaction (DC), as well as the dissolution of tablets. Significance The results obtained are meaningful to boosting the development and further research of PCPs on DC. Methods: In this study, hydroxypropyl methylcellulose (HPMC E3) and polyvinylpyrrolidone (PVP K30) were selected as shell materials, the Xiao Er Xi Shi formulation powder (XEXS) was used as the core materials, ammonium bicarbonate (NH4HCO3), and sodium bicarbonate (NaHCO3) were employed as pore-forming agent. Using co-spray drying method to prepare composite particles (CPs). Then, the physical properties and comparison between different CPs were characterized comprehensively. Finally, the different CPs were directly compacted as tablets to explore the effect on the dissolution behavior of DC tablets, respectively. Results (i) The XEXS PCPs were prepared successfully by co-spray drying, and the yield of PCPs is almost 80%; (ii) The TS values of PCP-X-P-Na, PCP-X-P-NH4, PCP-X-H-Na and PCP-X-P-Na were 5.70, 7.56, 3.98, and 6.88 times higher than that of raw material (X); (iii) The disintegration time of PCPs tablets decreased 10–25% when compared with CPs tablets; (iv) The values of Carr’s index (CI), Hausner ratio (HR), Caking strength (CS), and Cohesion index (CoI) of PCP-X-H-NH4 were 19.16%, 19.29%, 40.14%, and 6.39% lower than that of X, respectively. Conclusions The PCPs prepared by co-spray drying did improve the flowability and compactibility of powder, as well as the dissolution of tablets.

Experimental evaluation of lime spray drying for SO<sub>2</sub> absorption

<abstract> <p>This paper presents the findings of an experimental investigation on the performance of a laboratory-scale spray dryer involving flue gas desulfurization. Using commercial hydrated lime as a sorbent, a systematic set of experiments were performed to evaluate SO<sub>2</sub> absorption capacity of the spray dryer. The experimentation involved accurate measurement of the spray drying characteristics, such as temperature and SO<sub>2</sub> concentration along the spray chamber, by varying the input and output variables. Tests were done to investigate the effects of spray characteristics, i.e., inlet gas phase temperature (120–180 ℃) and calcium-to-sulfur ratio (1–2.5), on SO<sub>2</sub> removal efficiency. The performance of the spray dryer was further evaluated based on the degree of conversion of calcium (sorbent utilization) after SO<sub>2</sub> absorption. Results indicated an increase in SO<sub>2</sub> removal efficiency by increasing the stoichiometric ratio and decreasing the temperature. Absorption efficiency of SO<sub>2</sub> beyond 90% was achieved at a stoichiometric ratio of 2.5. A high degree of conversion of calcium was realized at low stoichiometric ratios, with a maximum utilization of 94% obtained at a stoichiometric ratio of 1.5. The analysis of the final desulfurization product revealed the presence of sulfite with better conversion achieved at a stoichiometric molar ratio of 1.5. A significant amount of unreacted sorbent (63.43%) was observed at a stoichiometric ratio of 2, while samples collected at a stoichiometric ratio of 1.5 had the lowest concentration of unreacted Ca[OH]<sub>2</sub> (41.23%).</p> </abstract>

Spray-Drying Hen Eggs: Effects of the Egg Yolk to Egg White Ratio and Sucrose Addition on the Physicochemical, Functional, and Nutritional Properties of Dried Products and on Their Amino Acid Profiles

Manufactured egg powders can be formulated to produce food products that vary in their properties. The present study aims to determine the effect of egg white content on the physicochemical characteristics and on the functionality and nutritional value of dried whole egg (WE), egg white (W), and an egg yolk/white mixture in a 1:3 ratio (M1:3). These fresh egg products were spray-dried using sucrose—an agent recognized for its effect of protecting the protein in the egg during the drying process. Experiments were conducted in a laboratory-scale spray dryer, operated under controlled conditions, with an air inlet temperature of 120 °C. In the dried products, water activity, water solubility index, color, and pH were affected significantly as a function of the fresh egg component ratio and the added sucrose. The wettability and dispersibility in water of egg powder were improved when sucrose was added to the WE. The water-holding capacity was highest in dried egg white, and higher in the M1:3 mixture without sucrose added than in the WE with 5% sucrose. The results suggest that modifying the ratio of fresh egg yolk to egg white could lend some control over the protein and fat contents of dried egg products and over their functional properties.

Modeling of a spray-drying process for the encapsulation of high-added value extracts from food by-products

The main goal of this research was to develop a mathematical model for a co-current spray drying-assisted encapsulation of natural extracts from grape pomace and citrus fruit peels, aiming to predict both structural features and the retention of their bioactive constituents. Model validation was performed using a laboratory scale spray dryer, analyzing the product in terms of moisture content, solids and total phenolic compounds recovery yields. The comparison between experimental and simulated results revealed that the model properly described the system. A slight effect of air inlet temperature was observed on the phenolic content of produced particles. For this reason, a kinetic law, which allows predicting the degradation of phenols was proposed and validated. These results highlighted the potential of spray-drying technology to efficiently encapsulate high-added value compounds with good preservation of their bioactive compounds, offering the possibility to decrease food waste issues while improving industry economic benefits.

Thermodynamic Balance vs. Computational Fluid Dynamics Approach for the Outlet Temperature Estimation of a Benchtop Spray Dryer.

The use of design space (DS) is a key milestone in the quality by design (QbD) of pharmaceutical processes. It should be considered from early laboratory development to industrial production, in order to support scientists with making decisions at each step of the product’s development life. Presently, there are no available data or methodologies for developing models for the implementation of design space (DS) on laboratory-scale spray dryers. Therefore, in this work, a comparison between two different modeling approaches, thermodynamics and computational fluid dynamics (CFD), to a laboratory spray dryer model have been evaluated. The models computed the outlet temperature () of the process with a new modeling strategy that includes machine learning to improve the model prediction. The model metrics calculated indicate how the thermodynamic model fits data better than CFD; indeed, the error of the CFD model increases towards higher values of and feed rate (), with a final mean absolute error of 10.43 K, compared to the 1.74 K error of the thermodynamic model. Successively, a DS of the studied spray dryer equipment has been implemented, showing how is strongly affected by variation, which accounts for about 40 times more than the gas flow rate () in the DS. The thermodynamic model, combined with the machine learning approach here proposed, could be used as a valid tool in the QbD development of spray-dried pharmaceutical products, starting from their early laboratory stages, replacing traditional trial-and-error methodologies, preventing process errors, and helping scientists with the following scale-up.

Analysis of heat and mass transfer in the manufacturing process of instant soy milk using a laboratory scale spray dryer

The events that occur during the drying include heat and mass transfer processes. So based on this, this research will discuss "Analysis of Heat and Mass Transfer in the Process of Making Instant Soy Milk Using a Laboratory Scale Spray Dryer". The research method used is the experimental method. The research that will be carried out will consist of preliminary research and main research. The purpose of this preliminary study was to determine the drying air temperature, fogging pressure, and the ratio of soy milk powder to water in solution. The best results from preliminary research are used in the main study. Data processing using technical analysis. The results showed that an increase in the drying air temperature of 80 ° C, 85 ° C, 90 ° C, 95 ° C, and 100 ° C caused a decrease in the need for drying air, namely 27.323 kg of dry air / hour to 9.840 kg of dry air / hour, time the drying of the material is shorter, namely 1 hour 10 minutes to 1 hour, the increase in thermal efficiency is 81.9% to 84.3%, and the increase in product weight coming out of the drying chamber is 3.1 grams to 4.1 grams. The results of the questionnaire showed that the panelists tended to rank taste first (65%), aroma second (61.25%), color third (47.5%).

A Design of Experiment Approach to Optimize Spray-Dried Powders Containing Pseudomonas aeruginosaPodoviridae and Myoviridae Bacteriophages.

In the present study, we evaluated the effect of spray-drying formulations and operating parameters of a laboratory-scale spray-dryer on the characteristics of spray-dried powders containing two Pseudomonas aeruginosa bacteriophages exhibiting different morphotypes: a podovirus (LUZ19) and a myovirus (14-1). We optimized the production process for bacteriophage-loaded powders, with an emphasis on long-term storage under ICH (international conference on harmonization) conditions. D-trehalose-/L-isoleucine-containing bacteriophage mixtures were spray-dried from aqueous solutions using a Büchi Mini Spray-dryer B-290 (Flawil, Switzerland). A response surface methodology was used for the optimization of the spray-drying process, with the following as-evaluated parameters: Inlet temperature, spray gas flow rate, and the D-trehalose/L-isoleucine ratio. The dried powders were characterized in terms of yield, residual moisture content, and bacteriophage lytic activity. L-isoleucine has demonstrated a positive impact on the activity of LUZ19, but a negative impact on 14-1. We observed a negligible impact of the inlet temperature and a positive correlation of the spray gas flow rate with bacteriophage activity. After optimization, we were able to obtain dry powder preparations of both bacteriophages, which were stable for a minimum of one year under different ICH storage conditions (up to and including 40 °C and 75% relative humidity).

Trileucine as a dispersibility enhancer of spray-dried inhalable microparticles

The formation of trileucine-containing spray-dried microparticles intended for pulmonary delivery was studied in depth. A single-particle method was employed to study the shell formation characteristics of trileucine in the presence of trehalose as a glass former, and an empirical correlation was proposed to predict the instance of shell formation. A droplet chain instrument was used to produce and collect monodisperse particles to examine morphology and calculate particle density for different levels of trileucine. It was observed that the addition of only 0.5 mg/mL (10% w/w) trileucine to a trehalose system could lower dried particle densities by approximately 1 g/cm3. In addition, a laboratory-scale spray dryer was used to produce batches of trileucine/trehalose powders in the respirable range. Raman spectroscopy demonstrated that both components were completely amorphous. Scanning electron microscopy and time-of-flight secondary ion mass spectrometry were used to study the particle morphologies and surface compositions. For all cases with trileucine, highly rugose particles with trileucine coverages of more than 60% by mass were observed with trileucine feed fractions of as little as 2% w/w. Moreover, it was seen that at lower trileucine content, smaller and larger particles of a polydisperse powder had slightly different surface compositions. The surface activity of trileucine was also modeled via a modified form of the diffusion equation inside an evaporating droplet that took into account initial surface adsorption and eventual surface desorption due to droplet shrinkage. Finally, using the Flory-Huggins theory, it was estimated that at room temperature, liquid-liquid phase separation would start when the trileucine reached an aqueous concentration of about 18 mg/mL. Besides the surface activity of trileucine, this low concentration was assumed to explain the substantial effect of trileucine on the morphology of spray-dried particles due to early phase separation. The methodology proposed in this study can be used in the rational design of trileucine-containing microparticles.

The Development of a Novel Pharmaceutical Formulation of D-Tagatose for Spray-Drying

D-tagatose is an alternative sweetener with superior properties for reducing overall sugar absorption, which is especially important in the diabetic population. Large-scale production of D-tagatose remains costly, thereby limiting its commercialization. Introducing the unit operation of spray-drying may reduce some of these costs. However, D-tagatose is challenging to spray-dry due to its hydrophilic nature and low glass transition temperature (Tg). An appropriate spray-drying feed solution may offer an alternative approach if the material produced is glassy in nature, thus avoiding stickiness issues associated with Tgs less than the outlet temperature of the spray-dryer. Proof-of-concept formulations and processing conditions are presented in this study. D-tagatose was formulated with several excipients and screened for a sufficiently high Tg as characterized by differential scanning calorimetry (DSC). The spray-dry formulations were further characterized using attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM), and several viable options were identified. D-tagatose formulated with HPMCAS and K90 both raised the Tg mix ( $$ {T}_{g_{\mathrm{mix}}} $$ ) to within the processing range of spray-drying. These formulations were found to be sufficiently soluble in acetone/water cosolvent systems allowing for the production of processable powder. Specifically, SEM results confirm that both D-tagatose-HPMCAS and D-tagatose-K90 formulations result in particle formation using a small-scale dryer. Large-scale spray-drying is expected to allow for a greater processing range in comparison to small scale, suggesting that this approach will help commercialization. ATR-FTIR and PXRD results suggested that spray-dried D-tagatose-K90 composites lacked crystallinity, unlike the D-tagatose-HPMCAS composites. The addition of functional excipients allowed D-tagatose composites to be harvested using a typical laboratory-scale spray-dryer equipped with a bi-fluid nozzle. D-tagatose-K90 lacks crystallinity, while crystallinity is present in D-tagatose-HPMCAS composites. Crystallinity may not be a critical factor (depending on the future application) given the high aqueous solubility and high loading of the sugar. Both composites retained a sweet taste, suggesting that this spray-drying method may be worth further development. Other polymers with high Tg may be feasible as composites as well—as long as the amorphous phase or the residual amorphous phase has a Tg greater than, or about equal to, the outlet temperature of the spray-dryer.

Computational Fluid Dynamics (CFD) Simulations of Spray Drying: Linking Drying Parameters with Experimental Aerosolization Performance.

The purpose of this study was to develop a new computational fluid dynamics (CFD)-based model of the complex transport and droplet drying kinetics within a laboratory-scale spray dryer, and relate CFD-predicted drying parameters to powder aerosolization metrics from a reference dry powder inhaler (DPI). A CFD model of the Buchi Nano Spray Dryer B-90 was developed that captured spray dryer conditions from a previous experimental study producing excipient enhanced growth powders with L-leucine as a dispersion enhancer. The CFD model accounted for two-way heat and mass transfer coupling between the phases and turbulent flow created by acoustic streaming from the mesh nebulizer. CFD-based drying parameters were averaged across all droplets in each spray dryer case and included droplet time-averaged drying rate (κavg), maximum instantaneous drying rate (κmax) and precipitation window. CFD results highlighted a chaotic drying environment in which time-averaged droplet drying rates (κavg) for each spray dryer case had high variability with coefficients of variation in the range of 60-70%. Maximum instantaneous droplet drying rates (κmax) were discovered that were two orders of magnitude above time-averaged drying rates. Comparing CFD-predicted drying parameters with experimentally determined mass median aerodynamic diameters (MMAD) and emitted doses (ED) from a reference DPI produced strong linear correlations with coefficients of determination as high as R2 = 0.98. For the spray dryer system and conditions considered, reducing the CFD-predicted maximum drying rate experienced by droplets improved the aerosolization performance (both MMAD and ED) when the powders were aerosolized with a reference DPI.

Hydration behavior of chia seed and spray drying of chia mucilage

Chia seeds (Salvia hispanica), rich in omega-3 fatty acids, were soaked in water with different seed to water ratios at 60°C for 10 hr. Mucilage was extracted using a stirrer at 2,000 rpm for 6 hr and centrifuged. Total soluble solids of collected gel was increased to 1% using maltodextrin and homogenized. Chia seed mucilage powder was produced by using laboratory-scale spray dryer at various temperatures, feed flow rates, and air flow rates. Effect of spray drying air temperature, feed flow rate, and air flow rate on chia mucilage powder cyclone recovery was studied to find the best combination of spray drying parameters to get high cyclone recovery. Seed to water ratio of 1:30 gave reasonable hydration yield with minimum water leftover. Combination of low drying air temperature, high pump flow, and high air flow (150°C, 475 ml/h, 54 m3/h) gave good cyclone recovery of chia seed mucilage powder. Practical applications Aim of this study is to produce chia mucilage powder using spray drying. Chia mucilage powder is made successfully through spray drying technique using very low quantity of maltodextrin even (to adjust mucilage to 1 °Brix only). However, maltodextrin does not give any merit to the resultant spray dried product, generally. Best combination of spray drying parameters were 150°C, 475 ml/h and 54 m3/h. They yielded chia seed mucilage powder cyclone recovery of 19.33%. With these spray drying process parameters, it is commercially viable to produce chia mucilage powder with low maltodextrin incorporated. The developed spray dried chia seed mucilage powder is white in color and suitable for all industrial applications in preparing food products, namely, bread, energy bars, tortilla chips, cake mixes, omega-3 enriched ready-to-eat cereal, chia flakes ready-to-eat cereal, omega-3 enriched pasta, chia pasta, muffins, cookies, snack bars, fabricated chips, energy drinks, etc.

Production and evaluation of vildagliptin-loaded poly(dl-lactide) and poly(dl-lactide-glycolide) micro-/nanoparticles: Response surface methodology approach

A laboratory scale spray dryer was used to encapsulate vildagliptin (VLG), an antihyperglycemic drug, into different polymers such as poly(dl-lactide) (PDLA), poly(dl-lactide-glycolide)-50:50 (PLGA 50:50), and poly(dl-lactide-glycolide)-75:25 (PLGA 75:25). Response surface methodology (RSM) was employed to evaluate the effects of process and formulation factors on the encapsulation efficiency (EE). The physicochemical properties of the drug-loaded micro-/nanoparticles, mainly the drug loading (DL), particle size distribution, surface morphology, drug–polymer compatibility, and release rate were investigated. % EE of drug-loaded micro-/nanoparticles were in the range of 57.10% to 76.44%. PLGA50:50 micro-/nanoparticles showed highest EE as compared to PDLA and PLGA75:25 micro-/nanoparticles. The mean particle size of the micro-/nanoparticles containing PLGA 50:50, PLGA 75:25, and PDLA polymers were 428 nm, 640 nm, and 1.22 µm, respectively. Surface morphology study revealed smooth, spherical and nonporous surface structures of the micro-/nanoparticles. Fourier transform infrared spectroscopy studies confirmed the drug–polymer compatibility. Powder X-ray diffraction analysis of micro-/nanoparticles revealed that VLG was present in the amorphous form within the micro-/nanoparticles formulations. In vitro release study demonstrated that VLG is slowly released from micro-/nanoparticles for 12 h and the drug release rate was influenced by type and viscosity of polymers used. This work suggests that PDLA, PLGA 50:50, and PLGA75:25 polymers are able to sustain the VLG release rates from micro-/nanoparticles.

Experimental investigations of particle formation from propellant and solvent droplets using a monodisperse spray dryer

Experimental studies of particle formation from solution droplets were conducted using a newly developed monodisperse spray drying process. Solutes beclomethasone dipropionate and caffeine were dissolved in ethanol, pressurized hydrofluoroalkane propellant 134a, and mixtures thereof. Solutions were atomized into monodisperse microdroplets using a custom droplet generator installed in a laboratory scale spray dryer, enabling drying and collection of the resulting monodisperse microparticles. The effects of droplet diameter, solution concentration, solvent composition, and drying rate on the physical properties of the dried particles were evaluated. Particle morphology and size were assessed using ultramicroscopy and image analysis of micrographs. Extent of crystallinity and polymorphism were investigated using Raman spectroscopy. The drying temperature was found to have a large effect on the morphology of amorphous beclomethasone dipropionate particles. Particles dried near room temperature were spheroidal to ellipsoidal with prevalent surface concavities and evidence of shell buckling; increasing the drying temperature for fixed droplet size and composition resulted in a transition to more spherical, smooth-surfaced particle morphologies. Crystalline caffeine microparticles were made up of assemblies of multiple crystallites. The measured length and breadth of these crystallites was found to be correlated with the time available for crystal nucleation and growth as calculated using a particle formation model. The results highlight the abilities and limitations of currently available particle formation models in elucidating the relationships between the size, composition, and evaporation rate of drying solution droplets and the physical properties of the resulting particles. The work demonstrates the suitability of monodisperse spray drying as an experimental technique for investigating the fundamentals of particle formation from solution droplets.© 2018 American Association for Aerosol Research

Inline method of droplet and particle size distribution analysis in dilute disperse systems

In the present article a measurement method of particle size distributions (PSD) in industrial installations which use a dispersed phase of low concentration (like spray dryers or spray scrubbers) is introduced. A new type of inline-measurement system has been developed and designed to work in spray drying conditions. A standard digital camera is used to record shadows of flowing particles inside the spray drying chamber. Collected images were analyzed by a newly developed software which recognizes particles only in the focus area and eliminates several types of artifacts. The constructed prototype of the PSD inline-analyzer was installed and used to monitor large laboratory scale spray dryer. All data collected by the designed system during the spray drying experiments were compared with data measured with an offline reference system to show accuracy of the new measurement technique.

648 Validation of micro-encapsulation method to protect probiotics and feed enzyme from rumen degradation

We hypothesize that supplementation of live yeast or feed enzyme (FE) may improve intestinal digestion and gut health, but with ruminants, the challenge is to deliver additive with high activity post-ruminally due to the highly proteolytic environment of the rumen. The objective of this study was to develop a micro-encapsulation method by measuring ruminal stability of encapsulated yeast and FE, and its release in the intestine. Live yeast and liquid FE were encapsulated using barley protein hordein and glutelin as capsule material. The barley protein powders were hydrated at pH 11.0 to form a 15% (w/v) solution. The pH was then adjusted to 7.0 followed by an immediate mixing with yeast or FE to form a coarse emulsion using a homogenizer. Microcapsules were then formed by passing the premixed emulsion through a microfluidizer system. The mixtures were spray-dried using a laboratory scale spray dryer. The ratio of capsule to additive was 1:1. The stability of encapsulated products in the rumen was measured as DM disappearance (DMD) in batch culture. Briefly, the encapsulated products (100 mg) were weighed into Ankom bags and placed in 100-mL serum bottles. Rumen inoculant (15 mL) from beef heifer and buffer solution (45 mL) was added to each bottle and incubated at 39°C for 0, 3, 6, 12 or 24 h. The residues in bags were digested in 1% pancreatin solution for 1 h to remove the encapsulation protection. Number of yeast colonies (cfu/g) was enumerated by spread plate method. Enzyme activity (EC 3.2.1.1) was assayed and expressed as μmol glucose equivalents/min/g FE. The DMD of encapsulated yeast were 3.1, 7.8, 9.1, 12.0 or 16.0%, and the cfu were 9.5, 2.2, 1.3, 1.1 and 0.6 (× 109), respectively, for residues after 0, 3, 6, 12, and 24 h of incubation. The DMD of encapsulated FE were 5.1, 31.4, 33.8, 40.6 or 43.6%, and the enzyme activity in residue were 41.9, 33.8, 19.7, 12.7 and 10.2 µmol/min/g, respectively, at 0, 3, 6, 12 and 24 h of incubation. The results showed that the encapsulated yeast products were stable in the rumen. Subsequently, the encapsulated yeast was released by digesting in pancreatin solution and cfu counts demonstrated over 90% survival rates. It suggests that this encapsulation technique is applicable as a novel method for delivering active yeast to the intestine. However, this technique may be not efficacy to protect liquid enzyme from rumen degradation.

Microwave Assisted Extraction of Avocado Oil from Avocado Skin and Encapsulation Using Spray Drying

The aim of this work was to extract the avocado oil from avocado skin. This oil was used to prepare the emulsion and encapsulation using spray drying. For the oil extraction, the efficiency of microwave assisted extraction (MAE) and soxhelt method was evaluated. The results indicated that MAE at 600 W for 15 min using 2-methyltetrahydrofuran gave the highest yield percentage. The emulsion preparation of avocado oil from MAE was prepared using the wall materials of maltodextrin and the Hi-Cap. The combinations of maltodextrin and Hi-Cap showed 100% stability for 24 hours, with no phase separation. The viscosity of the emulsions was reported at 11.00-13.00 mPa·s. The droplets mean diameter was between 2.05 to 2.08 µm. The microencapsulation of avocado oil was performed in a laboratory scale spray dryer. The encapsulation efficiency of three combinations of wall materials (F1 to F3) was valued of 60-80% which indicated that the increase on maltodextrin content, when combined to Hi-Cap, led to lower encapsulation efficiency. For particle characterization, the moisture content was 1.10-1.35 % and the bulk density was 0.35-0.37 g/cm3. Therefore, the proportion of wall materials had significant influence on the emulsion properties and on the encapsulation efficiency of avocado oil.

Preparation and Characterization of Magnetic Nano-in-Microparticles for Pulmonary Delivery.

The purpose of this chapter is to detail the formulation and characterization of a magnetically-targeted drug delivery vehicle, termed nano-in-microparticles (NIMs), for pulmonary drug delivery. Currently, chemotherapeutics and antibiotics are delivered systemically and result in whole body side-effects. NIMs are formulated with superparamagnetic iron oxide nanoparticles, termed SPIONs, making these particles targetable to specific lung regions using a strong external magnet. Additionally, these particles can be formulated to contain any drug or therapeutic agent, such that a therapeutic dose can be delivered to a specific tissue location using the SPIONs-magnet interaction. Finally, these particles are in the appropriate size range for pulmonary delivery, making NIMs therapeutics feasibly inhalable.To generate these particles a solution containing lactose, SPIONs, and a microsphere dye (used as a drug surrogate) is spray-dried using a laboratory-scale spray dryer. The resulting dry powder microparticles (NIMs) can be characterized for their size and morphological properties by various techniques that are presented in this chapter.The utility of NIMs as a magneticfield-dependent targeting delivery platform in an in vivo mouse model has been demonstrated, and a protocol detailing the intratracheal delivery of NIMs dry powder is included as a separate chapter in this book.

A novel rate of the reaction between NaOH with CO2 at low temperature in spray dryer

Abstract Carbon dioxide (CO 2 ) is an influential greenhouse gas that has a significant impact on global warming partly. Nowadays, many techniques are available to control and remove CO 2 in different chemical processes. Since the spray dryer has high removal efficiency rate, a laboratory-scale spray dryer is used to absorb carbon dioxide from air in aqueous solution of NaOH. In the present study, the impact of NaOH concentration, operating temperature and nozzle diameter on removal efficiency of CO 2 is explored through experimental study. Moreover, the reaction kinetic of NaOH with CO 2 is studied over the temperature range of 50–100 °C in a laboratory-scale spray dryer absorber. In the present contribution, a simple reaction rate equation is proposed that shows the lowest deviation from the experimental data with error less than 2%.

Spray dried SiO2 WO3/TiO2 and SiO2 vanadium pyrophosphate core-shell catalysts

Commercial catalytic gas-solid fluidized reactors operate best with a wide particle size distribution (PSD) centered around 70μm. Spray drying micro-sized powders with binders—colloidal silica, for example—provides the attrition resistance required to withstand the mechanical stresses inherent in these reactors. Commercial dryers 8m in diameter treat slurries at a rate of 1000kgh−1 and particle residence times are greater than 1min. Residence times in laboratory scale spray dryers are an order of magnitude lower. Droplets forming at the nozzle must be smaller in laboratory units so that they dry, consequently the average particle size is smaller. Here, we spray dried WO3/TiO2 and vanadium pyrophosphate catalysts with a combination of colloidal silica, polyvinyl alcohol and H3PO4 at 180° C and 245° C. The colloidal silica formed a 2μm shell at the outer surface of the particle regardless of the spray drying temperature. However, the lower temperature was insufficient to dry all the droplets formed at the nozzle and so particles agglomerated. Particle diameters are higher with high slurry concentrations and low atomization pressures, but the nozzle blocks when the slurry concentration is greater than 25%. Increasing the nozzle pressure to maintain the nozzle clear produces smaller droplets.