Search Results (88)

Background/Objectives: Wannachawee recipe (WCR) has been listed in the Hospital Traditional Medicine Formulary and has been used as a Thai medicine to treat psoriasis in the Thai Traditional Medicine Clinic of Prapokklao Hospital since 2006. Previous reports have found that WCR demonstrates good results for the treatment of patients with psoriasis. Among 136 Thai psoriasis patients who received WCR, 92.80% responded well. Although WCR is effective, there is still a lack of scientific data, especially relating to the bioactive compound in WCR. Therefore, this study aims to evaluate the phytochemicals in WCR via bioassay-guided isolation. Methods: In this study, the WCR was extracted via decoction with water, in a process based on traditional Thai medicine. The water extract was concentrated and dried using a spray dryer. The crude water extract was isolated using the partition technique with organic solvents, namely petroleum ether and ethyl acetate. These fractions were then separated and tested for anti-inflammatory activity using the bioassay-guided fractionation method. Results: Two particular types of pro-inflammatory cytokines are involved in inflammation and are among the factors that cause psoriasis—TNF-α and IL-6. Thus, we evaluated the isolated samples in terms of anti-inflammatory activity. The isolation resulted in two pure compounds—p-coumaryl aldehyde and trans-p-coumaryl alcohol. In the efficacy test of the isolated compounds, compared to the standard indomethacin at the same concentration of 12.5 ug/mL, trans-p-coumaryl alcohol was found to have the best efficacy, inhibiting TNF-α by 29.28% and IL-6 by 36.75%, with the standard compound showing inhibitions rates of 15.80% for TNF-α and 27.44% for IL-6. Conclusions: This study is the first report to identify the bioactive compound of WCR as trans-p-coumaryl alcohol or 4-hydroxycinnamyl alcohol. Full article

The spray-dried potato starch was produced by gelatinizing native potato starch at two concentrations of 3% and 5% at 75 °C for 30 min, followed by drying in a pilot-scale spray dryer. X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and optical microscopy were applied to characterize native potato starch and spray-dried (SD) potato starch powders. The physical properties of the starches, including moisture content, color, bulk density, tapped density, particle size parameters, water holding capacity, and hygroscopicity, were investigated. XRD, DSC, and FTIR revealed the formation of a semi-crystalline to amorphous structure in the spray-dried starch powders. Microscopic examination showed that the starch granules of native potato starch were spherical and regular in shape, while spray-dried (SD) starch powders displayed wrinkled granules. The moisture content of the spray-dried powders was significantly lower than that of the native starch, while the native starch had higher particle size values [D(4.3)] compared to the spray-dried powders. Higher water holding capacity values were also recorded in the spray-dried starches compared to the native starch. Regarding the color parameters, statistical analysis revealed similar values for lightness (L*) and yellowness (YI) indices, while significant differences were found in hue angle (H°), a*, and b* values. A principal component analysis (PCA) was carried out to investigate the relationships among the physical properties of the native potato starch and spray-dried starch powders. The findings of the present study highlight the potential application of physically modifying starch through the spray-drying process. Full article

Background: Atomization plays a key role in spray drying, a process widely used in the pharmaceutical, chemical, biological, and food and beverage industries. In the pharmaceutical industry, spray drying is particularly important in the preparation of amorphous solid dispersions, which enhance the bioavailability of active pharmaceutical ingredients when mixed with a polymer. Methods: In this study, a 3D-printed adaptation of a commercial spray dryer nozzle (PHARMA-SD^® PSD-1, GEA Group AG) was used to investigate the atomization of PVP-VA 64 polymer solutions under varying flow conditions using high-speed diffuse back-illumination. Results: Unlike pure water, the atomization process of the polymer solution was governed by viscous effects rather than surface tension, as indicated by stringing effects in the liquid core and the formation of larger droplets. In addition, the classical Ohnesorge diagram accurately predicted the atomization regime with increasing Reynolds numbers and could be modified to reasonably predict the breakup regime by considering the transitions between regime boundaries. Conclusions: The use of such a modified diagram facilitates the efficient selection of viscous fluid solutions and process parameters to achieve complete spray formation. Full article

(1) Background: Lippia sidoides Cham is a Brazilian aromatic plant rich in phenolic compounds. In traditional medicine, its leaves are used to treat diseases of the Central Nervous System such as stress and anxiety. This study evaluates the capacity of the aqueous extract of L. sidoides as an anticonvulsant, anticholinesterase and antihemolytic agent. (2) Methods: The extract was obtained from the leaves using water as a solvent, then dried in a spray dryer. The anticonvulsant effect was evaluated in zebrafish models using the pentylenetetrazol (PTZ) method. The anticholinesterase effect was determined using the acetylcholinesterase enzyme and physostigmine as a positive control. The antihemolytic action was evaluated by exposing erythrocytes to different concentrations of NaCl in the presence and absence of the extract. (3) Results: The anticonvulsant effect was observed at a concentration of 400 mg/kg, delaying convulsive crises. In the anticholinesterase assay, a dose-dependent action and variation in the effect over time were observed, demonstrating a reversible effect of the extract. For the osmotic fragility test, the extract showed satisfactory results, providing cellular protection across all variations of NaCl concentration. (4) Conclusions: These results demonstrate the promising potential of L. sidoides extract for the development of drugs that act in the treatment of diseases that affect the Central Nervous System. Full article

Background: Eugenol is a colourless or yellowish compound whose presence in clove essential oil surpasses the 75% of its composition. This phenylpropanoid, widely used as an antiseptic, anaesthetic and antioxidant, can be extracted by steam distillation from the dried flower buds of Syzygium aromaticum (L.). Due to its chemical instability in presence of light and air, it should be protected when developing a formulation to avoid or minimise its degradation. Methods: A promising approach would be encapsulation by spray drying, using natural coating products such as maltodextrin, gum arabic, and soy lecithin. To do so, a factorial design was carried out to evaluate the effect of five variables at two levels (inlet temperature, aspirator and flow rate, method of homogenisation of the emulsion and its eugenol:polymers ratio). Studied outcomes were yield and outlet temperature of the spray drying process, eugenol encapsulation efficiency, and particle size expressed as d_(0.9). Results: The best three formulations were prepared by using a lower amount of eugenol than polymers (1:2 ratio), homogenised by Ultra-Turrax^®, and pumped to the spray dryer at 35 m³/h. Inlet temperature and flow rate varied in the top three formulations, but their values in the best formulation (DF22) were 130 °C and 4.5 mL/min. These microcapsules encapsulated between 47.37% and 65.69% of eugenol and were spray-dried achieving more than a 57.20% of product recovery. Their size, ranged from 22.40 μm to 55.60 μm. Conclusions: Overall, the whole spray drying process was optimised, and biodegradable stable polymeric microcapsules containing eugenol were successfully prepared. Full article

The interest in using essential oils for biotechnological and biomedical applications has been increasing because of their unique properties, such as their roles as preservatives, antioxidants, antimicrobial agents, and therapeutic agents, with oregano oil being a notable example. However, the bioactivity and stability of oregano oil can be compromised because of its volatile nature and external factors like exposure to light, heat, or oxygen. To protect oregano oil from these adverse effects and enhance its potential, microencapsulation has been employed. Nevertheless, studies evaluating the economic feasibility of this process are still limited. In this context, this study combines an environmental impact assessment by applying the life cycle assessment (LCA) methodology and an economic evaluation of three different scenarios (A, B, and C) for the production of oregano oil microparticles by a spray dryer. In Scenario A, only modified starch was used to prepare the emulsion; in Scenario B, the modified starch was replaced with gum arabic; and in Scenario C, the gum arabic, maltodextrin, and modified starch were combined. The results indicated that Scenario B presents the best environmental performance for all impact categories analyzed (global warming, fossil resource scarcity, mineral resource scarcity, terrestrial acidification, freshwater eutrophication, and marine eutrophication). However, the composting of bio-waste end-of-life presents better environmental performance for the other scenarios (A and C). In Scenario B, the process with the lowest production cost per gram of microcapsules is the most promising for meeting the demands of the aspects analyzed. Full article

The efficacy of spray dry systems compared to wet flue gas desulphurisation (FGD) units depends on applying a highly reactive scrubbing reagent. This study assessed sodium-based compounds derived from natural sources and waste by-products as potential agents for treating sulphur dioxide (SO₂). Sodium carbonate (Na₂CO₃) and sodium bicarbonate (NaHCO₃) were acquired from mineral deposits, whereas the black ash waste (Na₂CO₃·NaHCO₃) was obtained from the pulp and paper sector. The sorbents introduced in slurry form were subject to SO₂ absorption conditions in a lab-scale spray dryer, including an inlet gas phase temperature of 120–180 °C, flue gas flow rate of 21–34 m³/h, and sodium to sulphur normalised stoichiometric ratio (Na:S) of 0.25–1. The comparative performance was evaluated using the metric of %SO₂ ($\%{\eta }_{DeS{O}_X}$) removal efficiency. The results showed that NaHCO₃ had the highest overall result, with a removal efficiency of 62% at saturation. Black ash was the second best-performing reagent, with a 56% removal efficiency, while Na₂CO₃ had the lowest efficiency (53%). The maximum degree of SO₂ reduction achieved using NaHCO₃ under specific operating parameters was at an NSR of 0.875 (69%), a reaction temperature of 120 °C (73%), and a gas inlet flow rate of 34 m³/h. In conclusion, the sodium reagents produced significant SO₂ neutralisation, exceeding 50% in their unprocessed state, which is within acceptable limits in small- to medium-sized coal-fired power plants considering retrofitting pollution control systems. Full article

The process integration and electrification concept has significant potential to support the industrial transition to low- and net-zero-carbon process heating. This increasingly essential concept requires an expanded set of process analysis tools to fully comprehend the interplay of heat recovery and process electrification (e.g., heat pumping). In this paper, new Exergy Pinch Analysis tools and methods are proposed that can set lower bound work targets by acutely balancing process heat recovery and heat pumping. As part of the analysis, net energy and exergy load curves enable visualization of energy and exergy surpluses and deficits. As extensions to the grand composite curve in conventional Pinch Analysis, these curves enable examination of different pocket-cutting strategies, revealing their distinct impacts on heat, exergy, and work targets. Demonstrated via case studies on a spray dryer and an evaporator, the exergy analysis targets net shaft-work correctly. In the evaporator case study, the analysis points to the heat recovery pockets playing an essential role in reducing the work target by 25.7%. The findings offer substantial potential for improved industrial energy management, providing a robust framework for engineers to enhance industrial process and energy sustainability. Full article

Indirect evaporative coolers (IECs) for air conditioning rely on liquid water being sprayed into the exhaust stream of used air to induce evaporation and cool down the incoming stream of fresh air in an indirect heat exchanger. This paper describes a computational fluid dynamics analysis that makes use of the particle transport model to simulate the evaporation of the water droplets at the exhaust side of an IEC using a pre-implemented spray dryer model. Critical parameters include the average size of the droplets and the amount of water sprayed into the system. In addition to droplet evaporation, the evaporation of water from the wet wall on the exhaust side is accounted for. The results show the calculated temperature field in both air streams, the pressure distribution, the relative humidity distribution at the exhaust side and the particle tracks. The predicted wet bulb efficiency of around 30–35% is moderate but in agreement with the literature to date, and it can be attributed to the small heat exchanger size. A parametric study investigated the effect of the droplet size and mass flow rate. At an average size of 50 microns and below, the effect of the mass flow rate is quite strong, while at a higher droplet size the mass flow effect is small. Overall, the model can be used to shed fundamental understanding in order to increase the performance of the IEC while maintaining its compactness. Full article

This study presents the formulation and development of a Reactive Engineering Approach (REA) kinetic model to characterize the drying kinetics of Trona across diverse experimental scenarios. By integrating fundamental reaction principles with experimental data, the REA model aimed at offering predictive capabilities to forecast trona drying behaviours. The model formulation involved solving both heat and mass transfer models to predict the drying behaviour and product quality such as temperature distribution and moisture content and along the spray dryer. The model equations were solved using finite difference method to develop a one-dimensional model. The validity of the developed REA kinetic model was assessed by comparing its predictions against the experimental data from diverse drying conditions. Experimentation involved drying Trona slurry under varying experimental condition such as slurry flowrate (12–28 mL/min), solid concentration (5–15%), inlet gas flowrate (40–80 m³/h) and inlet gas temperature (120–200 °C). This was carried out using a laboratory scale spray dryer while observing the spray characteristics including exit temperature and moisture content. The model simulation results presented close alignment with the experimental data indicating effective representation of the moisture loss behaviour under different operating conditions. Specifically, the model predicted higher rates of moisture loss at higher inlet gas temperatures (200 °C), consistent with experimental observations. Additionally, it indicated a decreasing rate of moisture loss along the chamber height (0–0.5 m) due to decreasing temperatures. Moreover, the model predicted a decreasing rate of moisture loss with increasing slurry concentration, consistent with final moisture content measurements. Full article

Aloe Barbadensis Miller, commonly known as Aloe vera, has been widely used in different applications, such as medicinal treatments and cosmetic products. However, its transportation and handling present challenges due to oxidation and property loss caused by direct environmental exposure. A strategy to mitigate these effects is dehydration, where different industrial-scale methods such as freeze-drying, spraying, refractory windows, and convective drying can be applied. Despite their effectiveness, those dehydration techniques are both energetically and economically costly. Solar drying technology offers a cost-effective, lower-energy alternative addressing sustainability, socioeconomic, scientific progress, and integrated sustainable development challenges. Nevertheless, solar drying through direct sunlight exposure has been minimally explored for drying high-water-content products like Aloe vera, potentially due to the inherent challenges of drying under uncontrolled environmental conditions. In response, this paper introduces a methodology for pre-treating and pre-drying Aloe vera gel using a low-cost solar dryer prototype, achieving up to 50% water activity reduction in experimental tests under uncontrolled conditions in Colombia, South America. The proposed prototype features a drying cabinet with energy autonomy and forced convection. The experimental evaluation compares the quality of pre-dried Aloe vera gel with freeze-dried samples, demonstrating comparable attributes under favorable environmental conditions. The results demonstrate the feasibility of pre-drying Aloe vera gel within 13 to 48 h, with a maximum drying rate of 0.38 g/min. During this process, water activity decreased from an initial value of 0.975 to a final value ranging between 0.472 and 0.748. Furthermore, the quality of the dehydrated gel was assessed through color analysis, comparing it with a freeze-dried sample. Subsequent color analysis of the freeze-dried samples revealed minor changes in product quality compared to those dried using the proposed solar drying method. These results demonstrate the effectiveness of the proposed solar dryer in pre-dehydrating Aloe vera gel, yielding characteristics similar to those achieved through conventional methods. Full article

Designing spray-dried particles for inhalation aims at specific physicochemical properties including a respirable aerodynamic diameter and adequate powder dispersibility. Leucine, an amphiphilic amino acid, has been shown to aid in optimizing bulk powder properties. Mannitol, a model crystalline active and common bulking agent, was co-sprayed with leucine at several excipient ratios, ethanol/water ratios, and spray dryer outlet temperatures in order to experimentally probe the underlying particle formation mechanisms in this binary crystalline system. During the droplet drying of two crystallizing components, the material that nucleates first will preferentially enrich the surface. It is desired to have a completely crystalline leucine shell to improve powder properties, however, mannitol competes with leucine for the surface depending on excipient concentration and manufacturing parameters. The resulting particles were studied initially and at a two-month timepoint via solid state characterization, visual analysis, and particle size analysis in order to detect changes in bulk powder properties. It was determined that, similar to systems where only leucine can crystallize, initial leucine saturation in the formulation dictates powder characteristics. Full article

With increasing computational capacities and advances in numerical methods, a simulation-based process and product design approach for spray dried products has become the focus of many researchers. In this context, a novel unresolved CFD-DEM simulation approach for single suspension droplets is presented, which models the drying and solidification process in a hot gas environment. The solidification process is described by the formation of bonds between the primary particles in the suspension droplet, showing a plausible solidification behavior, which starts when a critical solid concentration is reached at the droplet surface. The drying conditions for the single-droplet simulations are determined from a large-scale spray dryer simulation for different droplet size classes. The resulting solid particles from the CFD-DEM simulation show a higher tendency to form hollow particles at high drying rates when the locking point is reached at earlier stages of the drying process. Using these results, suitable operating conditions for the spray dryer can be determined, which favor the formation of particles with a targeted morphology. Full article

The ultrasonic-assisted spray dryer, also known as a nano spray dryer and predominantly used on a lab scale in the pharmaceutical and food industries, enables the production of nanometer-sized particles. In this study, the nano spray dryer was applied to cellulosic materials, such as cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs). CNC suspensions were successfully dried, while the CNF suspensions could not be dried, attributable to their longer fibril lengths. The nano spray drying process was performed under different drying conditions, including nebulizer hole sizes, solid concentrations, and gas flow rates. It was confirmed that the individual particle size of nano spray-dried CNCs (nano SDCNCs) decreased as the nebulizer hole sizes and solid contents of the suspensions decreased. The production rate of the nano spray dryer increased with higher solid contents and lower gas flow rates. The resulting nano SDCNCs were added to a polyvinyl alcohol (PVA) matrix as a reinforcing material to evaluate their reinforcement behavior in a plastic matrix using solvent casting. After incorporating the 20 wt.% nano SDCNCs into the PVA matrix, the tensile strength and tensile modulus elasticity of the neat PVA nanocomposite film increased by 22% and 32%, respectively, while preserving the transparency of the films. Full article

The use of adaptive meshing strategies to perform cost-effective transient simulations of spray drying processes is evaluated. These simulations are often computationally expensive, given the large differences between the characteristic times of the central jet and those of the unsteady flow developed at its periphery. Managing the computational cost through the control of the grid resolution by regions is inadequate in many of these applications since the grid resolution requirements change dynamically within the domain. These conditions are related to the unsteady nature of the flow in both the central jet and the flow recirculation zones. Therefore, the application of adaptive mesh refinement (AMR) strategies is recommended. In this paper, general AMR criteria based on relative errors are evaluated by testing three mesh adaptation criteria: velocity gradient, pressure gradient, and vorticity. This evaluation is performed using a low-cost turbulence model with eddy resolution (DDES) in two different types of drying chambers, in which experimental measurements are available. The use of AMR exerts appreciable effects on decreasing computational costs and contributes to the capture of large eddies in critical regions. The present approach provides an appropriate balance between solution accuracy and computational cost. By using a correct AMR configuration, it is possible to obtain results similar to those obtained on a fixed grid but reducing the computational costs by 3 to 5 times. Full article