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This paper proposes a comparative study of two techniques of granulation of a submicronic alumina powder with high binder content slurries, by spray drying and freeze granulation for the preparation of mixed granules. First, the viscosity and flow index of the suspensions are given as a function of dispersant, solid and binder contents versus alumina content, and the data are analysed in order to give a predictive model in a wide range. Suspensions with varying viscosities (7–208 mPa.s), densities (1.31–1.76) and surface tensions (23–40 mN/m) were then granulated. The first observations reveal the importance of the content and the molar mass of the binder: when they are too high, the freeze granulation fails and filaments are produced instead of granules due to extensive stretching of the molecular chains of the binder during spraying. Then through a theoretical analysis of the phenomena leading to granulation, an original dimensionless number is proposed to describe the evolution of the granule size as a function of suspension formulation. This number is related to the Reynolds and Weber number and is able to predict the granule size over a wide range (20–500 μm for freeze granulation, and 5–30 μm for spray drying). Spray drying leads to smaller granules with various shapes, from full shape to hollow or donut-like, whereas freeze granulation leads to bigger but spherical granules with a microporosity, and a size easier to predict as no drying shrinkage is observed.

The Wastewater Evaporation System (WES) was a reliable and economical way to treat desulfurization wastewater. However, the evaporation mechanism was not clear, and the evaporation product properties were lack of awareness. In this study, the evaporation and product properties were revealed by the single droplet drying (SDD) method and spray drying system. It was found that the evaporation process of wastewater involved the constant rate and falling rate period. The component of the evaporation product from the SDD and spray drying method were similar, mainly consisted of MgCl2, CaCl2, NaCl and CaSO4. Besides, the potential risks of WES were assessed. After wastewater evaporation, the Electrostatic Precipitator (ESP) removal efficiency was enhanced due to the aggregation of fine particles and the enhanced specific resistance. For the influence of WES on comprehensive fly ash utilization, the chloride mass fraction in the final product was lower than 0.06% and could meet strict regulations.

Phenolic compounds constitute important parts of natural bioactive ingredients due to their various biological activities. However, phenolic compounds are to some extent restricted by low solubility, poor stability, unpleasant taste and low bioavailability. Spray-drying microencapsulation is an effective strategy to ameliorate or even tackle such problems and it is crucial to choose optimal wall materials which may affect functional properties of the encapsulated components. In this review, we first described and discussed the physicochemical characteristics of commonly used wall materials for spray drying. Then we summarized the work done in past 16 years about the microencapsulation of phenolic compounds including anthocyanidin, curcumin, catechins, gallic acid, and resveratrol using spray drying is reviewed with a focus on the role of wall materials. Furthermore, we propose some targeted encapsulation strategies for different bioactive ingredients to explore their applications. Finally, we intend to encourage more research in rational selection of the wall materials.

In this study, vitamin B12, the most chemically complex and the largest molecule among all the vitamins, was successfully incorporated into zein microstructures via electrospinning and spray drying techniques. Scanning electron microscopy analysis revealed that different microstructures were obtained by electrospinning technique: films, microparticles and electrospun fibres. The vitamin B12 films presented a smooth surface and had around 90% of encapsulation efficiency. Vitamin B12-encapsulated zein microbeads, with a size of around 3 μm, were formed showing an efficiency of encapsulation of 91%. Electrospun fibres exhibited ribbon-shaped morphologies and had an encapsulation efficiency of 100%. By spray drying technique, wrinkled zein microparticles with vitamin B12 were produced with an encapsulation efficiency and product yield ranging between 71 and 95% and 67–83%, respectively. Kinetic models were applied to the experimental release profiles. The Weibull kinetic model showed the best fitting with the experimental data. The main drug transport mechanism associated to the experimental data is the Fickian diffusion (case I transport). The results suggest that the produced zein microstructures via spray drying and electrospinning techniques can be used as promising and effective alternative food and nutraceutical delivery systems.

Crystalline lactose microparticles with uniform size and spherical shape are greatly desirable for various applications, but still challenging. Herein, uniform lactose microspheres with high crystallinity were fabricated via spray drying lactose/polyethylene glycol (200 Da) (PEG 200) combined with ethanol/water post-treatment process. The effects of feed solution composition and ethanol/water volume ratio on particle size, morphology, density, crystal property and hygroscopicity were investigated. The obtained spherical lactose/PEG 200 microparticles were partially crystallized (30-50%), exhibiting dominant crystal forms of anhydrous Lα and Lβ. After removing PEG 200 by ethanol/water, the resulting microparticles remained uniform and spherical with enhanced crystallinity (92.90 ± 1.40%), high Lα·H2O content (68.57%) and ultra-low hygroscopicity (0.29%). Possible mechanism of “micro-zone competitive dissolution-reprecipitation” was proposed to reveal the influence of PEG 200 and ethanol/water volume ratio on promoting crystallinity and maintaining spherical morphology of lactose microparticles. This work provides a promising and up-scalable way to manufacture spherical crystalline microparticles.

Real (diabatic) spray drying processes have heat loss that affects drying kinetics. The heat loss depends on process parameters and on the type of spray drying equipment. Practically, heat loss can be determined by evaporating the solvent of a specific spray drying process with measurement of the outlet temperature after process equilibration. In this work, models to calculate the droplet evaporation time from an adiabatic (perfectly insulated) spray drying process are further developed to take heat loss into account. Comparison of different calculation models from water evaporation trials on a modified Buchi lab spray dryer with results from ANSYS 13.0 CFD simulations, show a good agreement for the introduced equations where heat loss is considered. The advantage of knowing the droplet evaporation time is that it condenses all relevant parameters of a specific spray drying process including material properties of the solvent to one single parameter affecting evaporation kinetics. The knowledge of the droplet evaporation time is of significant importance for scale-up activities, process transfers and optimizations as well as for particle engineering purposes.

Despite the advantages of targeting the pulmonary route through Dry Powder Inhalers (DPIs), the efficient delivery of biologics to the lungs still presents a considerable challenge: the generation of a powder with adequate aerodynamic properties while preserving the integrity of the biologic. Hence, the particle engineering technology employed to meet this balance plays a pivotal role. The present work describes a proof-of-concept study to investigate the effect of spray drying (SD) outlet temperature (Tout), atomization flow rate (Rotatom) and feed flow rate (Ffeed) on powder properties such as particle morphology and aerodynamic performance but also on the enzyme activity and protein conformational stability of a trehalose:leucine spray-dried powder featuring Cu,Zn-superoxide dismutase (Cu,Zn-SOD). This enzyme, often implicated in a broad spectrum of oxidative stress related diseases, from cystic fibrosis to rheumatoid arthritis, was used as a model Active Pharmaceutical Ingredient (API). Morphology and aerodynamic performance of the SD powders were determined by scanning electron microscopy (SEM), focused ion beam – SEM, laser diffraction and Andersen Cascade Impaction. For each SD run, enzyme activity retention (EAR) was measured by spectrophotometry and the protein melting temperature by differential scanning fluorimetry. To further understand the interaction between input and output variables, a statistical analysis was performed using SIMCA v13.0.3.0 software. Cu,Zn-SOD:trehalose:leucine spray dried powders were successfully generated upon different processing conditions, displaying fine particle fractions of ≈60% and EAR ranging from 50–80% with no loss of protein conformational stability. This technology thus proved to be suitable to prepare Cu,Zn-SOD based DPI powders within the considered working ranges.

The aim of this work was to encapsulate of citrulline extract from watermelon rind (by-product) by spray drying. Two different pectins were probed as wall materials in addition to maltodextrin. A Box-Behnken design was applied and three different parameters were evaluated as factors: commercial pectin (CP) concentration, orange produced pectin (OPP) concentration, and inlet air temperature. Different powder properties were evaluated as response variables including drying yield and encapsulation efficiency. The spray drying process was optimized by the desirability function. Higher drying yields, moisture contents and encapsulation efficiencies were reached at higher commercial pectin concentration. The optimal spray drying conditions were also determined. The obtained powder at the optimal conditions was characterized using Modulated differential scanning calorimetry and thermogravimetric analysis. In conclusion, citrulline extract spray-dried powders showed that could be stable during storage, so it might be used as an additive in foods to obtain functional products for human consumption.

Insecticides based on Azadirachta indica have been demonstrated as useful in pest control and bioinsecticides that are microencapsulated can reduce the amount of product utilized, and minimize impacts on the environment and human health. The objective of this study was to optimize drying, and evaluate the release and degradation kinetics of microencapsulated extracts from A. indica seeds. The Box-Behnken model (33) and surface response methodologies were used to find the best spray drying conditions for the chosen variables. They were: in-let temperature of 160 °C, feed flow of 3.3 mL/min, and nozzle diameter of 0.7 mm. The drying efficiency and EE under these conditions were respectively 71.15% ± 2.18 and 56.88% ± 0.28. In the release kinetics study, the release time for Azadirachtin (100%) was 20h. The 50% photo-degradation time for Azadirachtin was 21.07 days. Our results support industrial scale-up studies, and can help application measures in the field.

Zinc sulphate heptahydrate was microencapsulated by spray-drying using maltodextrin, HI-CAP® 100 and whey protein isolate as wall materials. Spray-drying conditions were optimised using Taguchi orthogonal array design with encapsulation efficiency and bulk density as responses. The influences of wall material, wall material to zinc ratio and inlet air temperature were evaluated. Microcapsules prepared with HI-CAP® 100 in 20:1 loading ratio at 185 °C had maximum encapsulation efficiency (92.65%), whereas 10:1 ratio yielded maximum bulk density (541.2 kg/m3). SEM micrographs revealed the spherical structure of microcapsules, while EDX confirmed the presence of zinc in the microcapsules. SEM micrographs, FTIR and XRD analyses showed that zinc was successfully encapsulated as microcapsules. The tapped, bulk and particle densities of zinc microcapsules were in the range of 586.15–698.15, 437.40–541.20 and 1263.25–1436.50 kg/m3, respectively, while flowability was ‘fair' to ‘passable’. The adsorption isotherm of microcapsules was sigmoidal, and was described by GAB model. Fortification of milk with zinc microcapsules did not affect its inherent organoleptic qualities.

The main objective of this research was to study the chia oil microencapsulation process in a co-current spray dryer. First, the effects of drying air inlet temperature and volumetric feed rate on the air temperature along the dryer, solid yield, physical properties of powders, and the estimated droplet evaporation time were assessed. Second, the evaporation time was predicted by means of a simple fundamental model, based on evaporation in still air and the constant rate period. Third, a global optimization of drying process conditions was performed. The main results showed that a uniform air temperature was found inside the dryer for all the process conditions, evidencing a well-mixed chamber. The estimated values of droplet evaporation times were between 1.23 and 2.55 s. Strong correlations between evaporation times and physical properties of powders (moisture content, surface oil content and encapsulation efficiency) were found. Finally, the process condition that simultaneously optimized dependent variables was 130 °C x 10 mL/min.

Microparticles containing the photosensitive spinosad (SP) were obtained using a combination of chitosan (CH) and sodium lignosulfonate (SL) as encapsulating materials to develop a photoprotective system for intake administration. The microparticles were obtained by a spray drying technique and were characterized in terms of morphology (scanning electron microscopy - SEM) and particle size. In vitro release studies showed an initial burst effect that fits very well with the zero order kinetic model and then a slow release of the bioinsecticide, which fits best with the first order model. The results of this work demonstrate that the bioinsecticide carrier system developed with natural polymeric materials presents high stability to photodegradation and adequate insecticide release for use as a strategy to reduce negative impacts on the environment in agronomic practices.

This work studied pineapple-mint juice drying by spray drying. The effect of 0, 3, and 15% of maltodextrin addition in the solution fed in the spray dryer was evaluated. The results showed that it is possible to dry pineapple-mint juice without a carrier agent. A two-level full factorial design of experiments was applied to quantify the effect of spray drying conditions (including the addition of 3% maltodextrin on pineapple-mint juice) on powder physicochemical properties. The estimated effects demonstrated that all variables have affected responses (except powder solubility). Interested in investigating pineapple-mint drying without maltodextrin, the two-level factorial design was further expanded to a central composite design, and additional experiments were realized, resulting in preservation of the natural green color of pineapple-mint juice, and a yield of 35%. The results suggest that mint may help in pineapple-mint juice drying.

Controlled agglomeration during spray drying offers several advantages for both powder manufacturers and consumers, and thus it is commonly implemented by industry. The implementation, however is largely based on experience, given the scarcity of comprehensive prediction tools. A resource-efficient approach to numerically treat agglomerates and yet provide an indication of their structures is desired to perform realistic simulations without the need for high-performance computing. In this work, a new numerical model for the treatment of coalescence and agglomeration was implemented and evaluated at two distinct scales with significantly different particle number densities within a Eulerian-Lagrangian CFD framework. The model could accurately predict the trends in the final particle size distributions and distinguish realistic agglomerate structures occurring under different conditions. Challenges were encountered as a result of how the underlying collision detection routine handles high particle number density. Several strategies are proposed to overcome these challenges. This work constitutes significant progress towards achieving an efficient prediction tool to estimate final powder properties and will prove useful in performing large-scale simulations to design and control agglomeration.

Development of spray drying of biomolecules has proved challenging primarily due to protein instability caused by high drying temperatures and atomization process. This study suggests a two-step approach towards a better understanding of spray drying process of large biomolecules. Using lysozyme as a model biomolecule a full factorial Design of Experiments (DoE) was employed to define the most critical process and formulation parameters. With respect to parameters such as feed rate, outlet temperature (Tout) and feed solid concentration, Tout was determined to be the most significant factor affecting the enzymatic activity. Forced deactivation studies were performed to identify critical points of potential enzymatic degradation during the drying process. Results show that lysozyme in solid form significantly inactivated when heated up to temperatures similar to Tout (70–90 °C). The approaches presented herein provide an improved understanding of the critical process and formulation parameters required for the successful spray drying of biomolecules.

Curcumin has been incorporated for the development of new products with applicability in food, pharmaceutical and cosmetic fields. However, the poor solubility in aqueous systems and very high sensitivity are the main concerns that need to be overcome during storage and processing. Microencapsulation technology may provide the required protection and stabilization of curcumin, preventing or reducing its degradation. The present work focuses on a new approach for the microencapsulation of curcumin from turmeric oleoresin (in alcoholic solutions) by a spray drying process using different biopolymers such as gum arabic, sodium alginate and a water-soluble modified chitosan as wall materials. Thus, a series of curcumin microcapsules were prepared and their physicochemical properties were analysed by laser granulometry and by scanning electron microscopy (SEM). Spherical microparticles with a mean diameter between 9 and 30 μm, considering a volume distribution, have been observed for all the biopolymers tested. The microparticles formed with gum arabic and alginate presented a very rough surface; on the other hand, the particles formed with the modified chitosan presented a smooth surface. The product yield obtained for the microparticles ranged from 46.1% to 57.3%. Curcumin release studies were performed and validated by a UV/VIS spectrophotometer using absorbance analysis. The results showed that all release profiles were similar, however with different total release times: 35 min, 2 h and 4 h for modified chitosan, alginate and gum arabic respectively, and the encapsulation efficiencies (EE) are between 93.8% and 97.6%. Moreover, all curves fit well to the Weibull model and to the Korsmeyer-Peppas model. This work shows that it is possible to encapsulate curcumin (in alcoholic solutions) using different biopolymers, through a spray-drying process.

In India, groundnut is mainly used for oil extraction or consumed in roasted form prompting a need for diversification to further increase its value and utility. In the present study, spray drying of groundnut milk was carried out using three variables of spray dryer i.e., inlet air temperature (180–220 °C), atomization air pressure (2–3 bar), feed pump speed (24–36 rpm) using Box-Behnken design of Response Surface methodology. The moisture content of powder decreased with an increase in inlet air temperature and atomization air pressure. The bulk density increased with increase in atomization air pressure. Maximum dispersibility (98.48%) was observed at an atomization air pressure of 2.57 bar. The insolubility index of the powder increased and lightness value (L*) decreased with an increase in inlet air temperature. The optimized conditions for spray drying of groundnut milk were inlet air temperature: 186 °C, atomizing air pressure: 2.5 bar and feed pump speed: 27 rpm.

The objectives of the current work were (a) to investigate the suitability of soluplus®, a hydrophilic polymer, as a carrier for the entrapment of curcumin (CUR) SEDDS by the spray-drying process, and (b) to compare soluplus® with neusilin® US2, a hydrophobic high-capacity adsorbent for solid SEDDS. Both carriers produced free flowing powders with high CUR entrapment efficiency. When filled into capsules, approximately 95% of CUR was dissolved from the soluplus® powder within 120 min and only 41% from the neusilin® US2 base powder. When the powders were compressed into tablets, a slow CUR release was observed over 24 h, which varied as a function of compression force and the percentage of disintegrant used. In conclusion, current study demonstrated the feasibility of using soluplus® as a carrier for the preparation of solid SEDDS with more favorable release profiles when compared to the conventional hydrophobic adsorbents.

In this study, sour cherry seed oil (SCSO) loaded gum Arabic (GA)-Maltodextrin (MD) microcapsules were developed by using spray-drying technique. The optimum processing conditions determined using the response surface methodology (RSM) were as follows: a weight ratio of GA to MD (GA:MD composition) of 1:11, a weight ratio of oil to total solid (core-wall ratio) of 20%, and inlet temperature of 195 °C. SCSO powder (SCSOP) was characterized in terms of morphology and size using scanning electron microscopy (SEM), and a laser particle diameter analyzer. The presence of SCSO in GA/MD matrix was confirmed by using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The thermal stability of the SCSOP was assessed using thermogravimetric (TGA) and differential thermal analysis (DTA). Microencapsulation provided a remarkable oxidative stability to SCSOP compared to free sour cherry oil. The antimicrobial potential of the microcapsules were assessed against pathogenic bacteria, yeast and mold.

Application behavior of spray dried powders such as reconstitution behavior and flowability is indirectly influenced by powder particle morphology. We here investigated the influence of the drying conditions and composition for whey protein (WP), maltodextrin (MD) and their mixtures on particle morphology during pilot-scale spray drying. Even though all powders showed a variety of morphologies, MD powders contained more wrinkled particles and had high bulk density, whereas pure WP powders contained more hollow particles. Mixture powders (75:25 WP:MD) show more hollow particles with increasing inlet temperature, with a lower bulk density. The observed morphologies for different formulations corresponded roughly to previous observations during sessile single droplet drying, but the results indicate that the morphology is also influenced by the faster pilot-scale drying, which was not evident in the slower single droplet drying.

This paper reports the synthesis of LiNi0.8Co0.15Al0.05O2 (NCA) cathode powders using a simple flame assisted spray pyrolysis (FSP) and a spray drying (SD) processes, in which metal salt precursors dissolved in glycerol were used for spraying. X-ray diffraction confirms that the NCA powders have a layered structure, with a low order of cationic mixing. Electron microscopy shows that the particles produced by FSP have a relatively smaller size and a smoother surface than that produced by SD. The NCA powder from the FSP process has an initial discharge capacity of 200.2 mAh/g in voltage range of 3.0–4.3 V at 0.1C. It shows very good capacity retention of 91.5% at 1C and 89.4% at 5C after 200 cycles. These results demonstrate that glycerol can replace water and be used as a solvent in spray processes to make cathode powders, promising a new environmentally-friendly synthesis route for battery powder materials production.

This study investigated the microencapsulation of fermented noni juice (FNJ) via a novel pilot scale micro-fluidic-jet-spray-dryer (MFJSD). Different concentrations of maltodextrin (M1, 10–13 DE; M3, 17–20 DE) and gum acacia (GA) were used as wall materials. The physicochemical properties, microstructure, droplet-to-particle formation process and bioactives stability of the powders produced by the MFJSD were examined. Results showed that the M1 powders with 28% solid content (M1, 28%) exhibited better bulk density, particle size, glass transition temperature and hygroscopicity than the other three powders produced (namely the M1 (21%), M3 (28%) and GA (21%) powders). The FNJ powders underwent five different stages during the drying process, from isotropical drying, crust formation, solidification and buckling to final particle formation. The external surface morphology of the powders was obviously influenced by the wall materials selected. However, the drying and wall material type have limited effect on the stability of bioactives in the FNJ powders after microencapsulation and during storage. This study provided insight into the micro-fluidic-jet spray drying of FNJ, and evaluated the properties and stabilities of the powders produced.

Anchovy oil was successfully encapsulated into multi-core microcapsule powder using a two-step microencapsulation method. The inner and outer shells of the microcapsules were created separately using gelatin-SHMP complex coacervates as shell materials. Fucoidan extract was used to crosslink these complex coacervates shells of microcapsules before spray drying. The spray dried microcapsules produced using the two-step method exhibited high encapsulation efficiency (99.83%), low surface oil content (0.10%), high oil payload (55.68%) and significantly improved oxidative stability. The formation of the outer shell during the second cooling step of two-step microencapsulation method significantly improved the oxidative stability of the anchovy oil by smoothing the surface of the microcapsules.

The main goal of this work was to assess if the Supercritical CO2-Assisted Spray Drying (SASD) is a competitive technology for the production of inhalable trehalose and leucine composite particles with advantageous properties and aerodynamic performance while ensuring a high process throughput and yield. For that purpose, a systematic Quality-by-Design approach using the design of experiments tool, followed by a statistical analysis were implemented. A full-factorial design was used to assess the impact of the static mixer pressure, inlet drying gas temperature and feed flowrate on the powder physical properties and in vitro aerodynamic performance. The powders were produced through SASD with yields up to 70%, while enabling the optimization of the overall throughput. Improved in-vitro aerodynamic performance was driven by the successful manipulation of the process parameters, namely by decreasing the feed flowrate and increasing the inlet drying temperature, yielding powders with fine particle fraction values up to 86%.

The formulation of bioactive powders is crucial to their property, functionality and bioaccessibility. This study investigated the incorporation of Ca2+ as a protectant aid for producing active dry probiotics via spray drying, and explored the mechanism underlying the positive effect of Ca2+ on cell viability. At inlet temperature of 98 °C and outlet temperature of 65 °C, supplementing 1 mM CaCl2 to either 10 wt% lactose or 10 wt% trehalose solution increased the survival ratio of Lactobacillus rhamnosus GG (LGG) from 5% to 30%. The growth capability of dried LGG was also enhanced in the presence of calcium. Powder properties including particle morphology, amorphous state and infrared spectrum were minimally influenced at such a low Ca2+ loading. By contrast, adding 1 or 100 mM Ca2+ in reconstitution solution or MRS agar plates notably improved the survival of LGG cells during single droplet drying with pure lactose protectant. The findings suggested that the protective mechanism of Ca2+ is based on enhancing the intrinsic tolerance of LGG cells, rather than modifying the powder properties. Given the protective effect of Ca2+ on probiotic cells under stressful conditions, calcium-containing dry probiotic products that confer duel benefits to consumers may be developed as new types of functional foods.

The encapsulation of phase change materials (PCM) is the essential step to make PCM easily utilizable. Aiming for a feasible process on a large scale, the combination of PCM/sol-gel emulsion and the spray-dry process was employed for the production of PCM encapsulated in silica shell matrices. Two PCMs, methyl palmitate and n-octadecane, with operating temperature appropriated for thermal comfort in trocical countries were selected. The composition of emulsion, i.e. tetraethyl orthosilicate (TEOS), cetyl trimethyl ammonium bromide (CTAB), and n-octadecane or methyl palmitate, was varied to find the optimal conditions for encapsulation. The influence of composition and process time on PCM's emulsion stability, size and structure of microcapsules, and encapsulation efficiency were investigated. The results showed that the optimal PCM to silica ratio was determined by the maximum quantity that could maintain the rigidity of the microcapsule structure. The low surfactant concentration that could still sustain emulsion stability contributed to improved encapsulation efficiency.

In this research, date powder was produced by drying aids including Tween 80, pectin, and whey protein concentrate (WPC) at different pH values (5.0, 6.5, 8.0, and 9.5) and using a spray drier at different temperatures (160, 170, 180, and 190 °C); then moisture content, solubility, hygroscopicity, bulk density, and total phenolic compounds (TPC) were determined and their correlation with structural characteristics of date powder was analyzed by Taguchi method. Interactions of pectin-surfactant, and pectin-WPC were more effective on moisture and bulk density of date powder, respectively. Although hygroscopicity of different treatments was in narrow range of 25–29%, temperature had the highest impact on TPC; beyond 170 °C, TPC of date powder decreased. Treatment No. 7, with the highest WPC level and pH values of 5, maintained the highest TPC content (701 mg 100 g−1) in date powder. SEM images revealed that pH = 9.5 and lower temperatures led to smaller particles.

The microencapsulation process of Trichoderma spp. by spray drying (SD) aims at the protection and suitability of these to the use in agriculture as controllers of phytopathogens. The objective of this study was to evaluate the lethality temperature of Trichoderma asperellum conidia by spray drying, studying the use of sucrose (SU), maltodextrin DE20 (MD20), gum arabic (GA), whey powder (WH) and lactose (LA) as wall materials (WM) in the microencapsulation process. The lethality curves of Trichoderma asperellum conidia dry in SD without wall material were analyzed between the drying temperatures of 60 to 120 °C. The microcapsules with the various wall materials were dried at 80, 90 and 100 °C. The five different wall materials were characterized for their moisture, water activity, hygroscopicity, water solubility and viscosity in suspension. The microcapsules produced were evaluated for moisture, water activity, conidial viability (CV), survival percentage (SP) and scanning electron microscopy (SEM). The highest percentages of conidial lethality were observed at drying temperatures above 90 °C, both for the tests with and without the wall materials. Among the wall materials studied, the highest percentage of conidia survival with 90 °C drying air temperature was maltodextrin DE20 (92.89 ± 1.47%), followed by whey (82.84 ± 2.35%), sucrose (82.55 ± 2.01%), gum arabic (81.59 ± 0.37%) and lactose (44.73 ± 0.40%). After obtaining the results it was verified that the MD20 presented high potential for the microencapsulation process, thus, the lethality curves of the conidia microencapsulated with MD20 were made by varying the inlet air temperature from 60 to 120 °C. The data obtained showed that even with the addition of wall material, when air inlet temperatures above 90 °C were used, it was not possible to maintain the cell viability of the conidia.

Feijoa (Acca sellowiana B.) is a fruit harvested in South America that is characterized by its nutritional value, high pectin content and high trading potential. In this study, freeze concentration was combined with spray drying to produce feijoa powder. Freeze concentration technology is proposed as a step prior to spray drying to increase the solid concentration and to avoid the feijoa gelation process. The drying parameters were optimized by studying the inlet air temperature (180, 195 and 210 °C), maltodextrin concentration (7, 16 and 25%) and atomizer system (two-fluid nozzle or rotary disk) on a pilot scale spray dryer. The process yield, moisture content, water activity, hygroscopicity, solubility, and colour preservation were determined. The freeze concentration technique allowed the solid content to increase without causing gelation and with low differences in colour. Statistical analysis showed that the maltodextrin concentration significantly affected all the response variables after spray drying. In addition, the temperature affected the solute yield and particle size. The optimum spray drying conditions to obtain feijoa pulp powder were 22.64% maltodextrin concentration, 180 °C inlet air temperature and nozzle as the atomizer system. At these optimum conditions, feijoa pulp powder with a 26.6% process yield, 6.5% (wb) moisture content, 20.7% hygroscopicity, 0.16 water activity, 92.8% solubility and ΔE of 27.71 were obtained. The combination of freeze concentration and spray drying allowed the production of fruit pulp powders from sensitive or gelled fruit pulps.

The objective of present study was to optimize spray drying of Risperidone (RIS) nanosuspension for achieving lower particle size, higher yield and good compressibility of spray dried powder using Quality by design approach. RIS nanosuspension was prepared by anti-solvent precipitation technique using poloxamer 68 and Poloxamer 127 as stabilizers. 3 level 2 factorial design was applied using two independent factor variables viz., X1: feed pump speed (RPM) and X2: inlet temperature (oC) and their effect upon dependent variables viz., Y1: Size, and Y2: %Entrapment efficiency was determined at three different levels. Spray dried powder was further characterized for bulk level properties and formulated as an orally dispersible tablet (ODT). The developed ODT were characterized by various parameters like wetting time, disintegration time, hardness, friability, weight variation and dissolution for comparison. Size and PDI of formulated RIS Nanosuspension were found to be 200.00 ± 0.40 nm and 0.210 ± 0.03 respectively. Optimized process parameters for spray dryer were obtained from design space, which gave critical quality attributes (CQA) response of lowest size and highest yield of 214.21 ± 2.01 nm and 61.85 ± 1.02% respectively. FTIR, DSC, XRD and AFM studies of spray dried RIS nanosuspension revealed that crystallinity of RIS was altered during spray drying process. Bulk density, Tapped density, Hausner ratio, Compressibility index and Angle of repose of spray dried RIS was found to be 0.588 ± 0.12 g/mL, 0.641 ± 0.20 g/mL, 1.09 ± 0.26, 8.33 ± 0.32 and 32.40o ± 0.98o respectively. ODT formulated using optimized spray dried nanosuspension showed higher dissolution than marketed ODT formulation which may be due to increase in solubility of Risperidone during spray drying of nanosuspension.

The aim of this study was to develop a modified release system (MRS), hydrophilic matrix type, containing Physalis peruviana fruit extract as the active ingredient. For this purpose, a co-processing method via spray-drying was used, whose conditions were previously established, using in the formulation silicon dioxide as a drying aid and HPMC K15M as a polymer, to modulate the release of the extract. Four formulations were prepared, and pharmacotecnical properties and hypoglycemic in vitro assay were evaluated; in these formulations, the ratio of the polymer was changed to find the influence of this excipient on the release of the extract, from the hydrophilic matrices, under different pH conditions simulating the gastrointestinal tract. To selected formulation from this test, other assays were performed such as erosion studies, water uptake and movement fronts, which complemented the evaluation on the release mechanism. It was established that composition of the co-processed with and without polymer, presented good flow and compaction properties. The characterization of the MRS showed a modulated release of the extract, the concentration of the polymer was the main factor that affected its release rate. Formulation Ex: SiO2: HPMC-K15M (55.2%: 41.4%: 3.4%) was selected, among the formulations evaluated, because it presented adequate modulation of the extract release. The release mechanism was a combination of diffusion of the extract and erosion of the matrix. The in-vitro studies showed that the excipients and the process did not significantly influence the hypoglycemiant activity of the extract.

The objective of this work was to evaluate the influence of the homogenization method, ultrasound or rotor-stator, on the properties of emulsions formed with chia oil (Salvia hispanica L.) and on the stability of this powder oil. Microencapsulation was performed by spray drying, using as a wall material a mixture of maltodextrin 10DE, maltodextrin 20DE, whey protein isolate and gum arabic (40/40/15/5). The characterization of the microparticles was performed by moisture, particle size, surface oil, encapsulated oil, encapsulation efficiency, morphology, lipid oxidation and oxidative stability. The use of ultrasound promoted a significant reduction in droplet size (4.62 to 0.48 μm) and a considerable increase in encapsulation efficiency (42 to 96%). In this way, it was possible to obtain a microparticle of chia oil with concentration of oil of industrial interest (30% w/w) with high encapsulation efficiency and good oxidative stability, using the green ultrasonic technology for the oil homogenization stage.

Novel carrier-based delivery systems have been strategically designed and developed to beneficiate retinoic acid (RA) as medical agent. The final purpose is to deal with the factors which hamper RA efficacy (e.g. short half-life, low absorption in the intestine and severe side effects). The present work proposes the inclusion of RA into arabic gum, modified chitosan and alginic acid sodium microcapsules using spray-drying technology. The product yield varied between 26 and 38% for empty and RA-loaded microcapsules. Spherical microcapsules with a rough, slightly rough and smooth surface (according to the encapsulating agent) and with an average size in the range of 3.279 to 10.880 μm were obtained. Controlled release studies evidenced the fastest RA release (in 99 min) for the modified chitosan formulation, while alginic acid sodium microcapsules enabled a RA release for >7 h. The main kinetic release models, based on different mathematical functions, were applied to RA. The Weibull model revealed to be the most appropriate to characterize the RA release profiles.

The extract obtained from blackberry (Rubus fruticosus) residues was encapsulated in polyvinylpyrrolidone (PVP) by three methods: the conventional spray-drying (SD) and freeze-drying (FD) techniques, and the new method of supercritical antisolvent (SAS), using CO2 as antisolvent and ethanol as solvent of the organic solution (extract + PVP). The methods and their produced particles were evaluated in terms of precipitation yield, residual ethanol and moisture contents, anthocyanin concentration, antioxidant capacity, morphology, crystallinity and thermal stability. SD,FD and SAS achieved particles with good anthocyanin yields (above 76%), high antioxidant capacity (above 100 μmol TE/g particle) and were effective to concentrate anthocyanins in PVP without great degradation. Using SAS, particles with 1.42 mg ECy3Gl/g were achieved. Nevertheless, SAS particles presented high residual ethanol (8.17% w/w) and moisture (11.30% w/w), whereas in SD and FD particles these contents remained below 2 and 5%, respectively. Scanning electron microscopy revealed a spherical shape in the particles obtained by SD, while those produced by SAS and FD presented irregular agglomerates. The encapsulation processes were equivalent in terms of thermal protection of the extracts and they did not modify the crystallinity and thermal behavior of PVP. The SAS process achieved preferential precipitation of anthocyanins when compared to SD and FD, since supercritical CO2 does not have any affinity to such compounds.

Microencapsulation, increasingly considered a good alternative for retaining flavours and protecting them from degradation, is destined to have a great impact in the food industry. In the present study, the strawberry flavour was spray dried using different encapsulating agents such as maltodextrins (MDs), modified starch (Hi-Cap), arabic gum (AG), xanthan gum (X) and β-cyclodextrin (β-CD). Mixtures with different concentrations of these carriers were prepared and the stability, apparent viscosity and density were studied. The foam phase varied between 2 and 22%, the apparent viscosity ranged from 0.045 to 1.13 Pa·s and the density was approximately 1280 kg/m3. Those mixtures considered the most suitable were spray dried using 180 °C as inlet temperature, and analyzed by gas chromatography–mass spectrometry (GC–MS). The drying yield varied between 45 and 57%, excluding the blend MDs/X/β-CDs. The blend MDs/Hi-Cap/β-CDs presented the best results in terms of the encapsulation efficiency of volatile compounds. In the case of the moisture content the values obtained ranged from 1.3 to 3.3%. SEM analysis showed that MDs/Hi-Cap/β-CDs and MDs/AG/β-CDs led to the formation of spherical, more homogeneous, and smoother particles. The results indicated that the blend MDs/Hi-Cap/β-CDs exhibited the best properties for encapsulating the flavour, followed by MDs/AG/β-CDs and MDs/X/β-CDs.

In the present study, different solid self-nanoemulsifying drug delivery system (S-SNEDDS) was formulated by using porous hydrophilic and hydrophobic carriers to improve the dissolution rate and bioavailability of simvastatin (SIM). The prepared liquid-SNEDDS composed of Labrafil M 1944 CS/ Tween-80/ Ethanol (20% / 53.33%/26.67% v/v) with 0.1% SIM, resulted droplet size of 40.69 nm. The hydrophobic carriers used were Aerosil-200, Syloid 244FP, Syloid XDP 3150, Magnesium stearate, Micro Crystalline Cellulose PH102 and lactose and hydrophilic carriers used were Poly vinyl alcohol, Sodium carboxy methyl cellulose and hydroxypropyl-β-cyclodextrin. These S-SNEDDS were characterized through micromeritic, biopharmaceutical studies and stability studies. The spray dried S-SNEDDS prepared by using Aerosil 200 as hydrophobic carrier provided nanoemulsions with unchanged droplet size and drug release when subjected at different stress conditions such as thermodynamic stress and freeze thaw cycles. In vitro dissolution studies revealed that the L-SNEDDS and S-SNEDDS of Aerosil 200 were found to be remarkably superior over the unprocessed SIM and marketed SIM. Scanning electron microscope, Differential scanning calorimeter and Powder X-Ray Diffraction revealed crystalline SIM was present in a changed amorphous state in the SNEDDS formulations prepared with Aerosil 200 as carrier. Further, pharmacokinetic study carried out on rats revealed 0.5 h increase in time for maximal concentration (Tmax), 3.75 folds increase in maximal concentration (Cmax), 1.22 h increase in mean residence time, 1.54 folds increase in area under curve (AUC0-t), 2.10 folds increase in AUC0-∞ and 3.28 folds increase in bioavailability confirms that the developed S-SNEDDS were superior than that of marketed formulation. Hence, it can be safely concluded that Aerosil 200 based S-SNEDDS were able to provide improvement in dissolution rate and oral bioavailability of SIM.

The current study was intended to improve operational conditions for spray drying of Murraya koenigii (Linn) leaves extract by using response surface methodology (RSM). The inlet air temperature (140–180 °C), maltodextrin concentration (10–30 %), and gum acacia concentration (2–10 %) were kept as an independent variables while optimizing responses were powder yield, moisture content, solubility, and total phenolic content. The quadratic equation and statistical analysis showed a substantial effect on all the responses and the optimized conditions for spray drying of Murraya koenigii extract validated the quadratic model. The most desirable optimum conditions for spray drying of Murraya koenigii leaves were, inlet temperature (165 °C), maltodextrin (30 %), and gum acacia (10 %) for obtaining desired characteristics of spray dried powder such as solubility (26.15 %), total phenolic content (253.42 mg/g), and moisture content (3.03 %) respectively at a desirability level of 0.918 with powder yield (27.61 %).