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Concept: Spray nozzle


The present study was conducted to examine the feasibility of nimodipine loaded PLGA microparticles suspended in Tisseel(™) fibrin sealant as an in situ forming depot system. This device locally placed can be used for the treatment of vasospasm after a subarachnoid hemorrhage. Microparticles were prepared via spray drying by using the vibration mesh spray technology of Nano Spray Dryer B-90. Spherically shaped microparticles with different loadings and high encapsulation efficiencies of 93.3% to 97.8% were obtained. Depending on nimodipine loading (10% - 40%) the particle diameter ranged from 1.9 ± 1.2 μm to 2.4 ± 1.3μm. Thermal analyses using DSC revealed that Nimodipine is dissolved in the PLGA matrix. Also fluorescent dye loaded microparticles were encapsulated in Tisseel(™) to examine the homogeneity of particles. 3D-pictures of the in situ forming devices displayed uniform particle homogeneity in the sealant matrix. Drug release was examined by fluorescence spectrophotometry which demonstrated a drug release proportional to the square root of time. A prolonged drug release of 19.5 h was demonstrated under in vitro conditions. Overall, the Nimodipine in situ forming device could be a promising candidate for the local treatment of vasospasm after a subarachnoid hemorrhage.

Concepts: Scientific method, Subarachnoid hemorrhage, In vitro, In situ, Spray drying, Vasospasm, Spray nozzle, Nano spray dryer


Vinegar and eggs have rich nutrients. In this study, the mixed form of both derived products, vinegar-egg solution and its products (vinegar-egg concentrate and vinegar-egg condensate) were chosen for an assessment of their biological activity. To further our understanding regarding the anticancer and immunomodulatory effects of vinegar-egg, we investigated its effects on the proliferation and differentiation of U937 cells. Vinegar-egg was treated using spray drying, freeze drying and vacuum concentration and used to stimulate human mononuclear cells. The conditioned media obtained from these cultures by filtration were used to treat U937 cells. Three conditioned media inhibited U937 cell growth by 22.1-67.25% more effectively than PHA-treated control (22.53%). CD11b and CD14 expression on the treated U937 cells were 29.1-45.4% and 31.6-47.2%, respectively. High levels of cytokines IL-1β, IFN-γ and TNF-α were detected in the three conditioned media. Vinegar-egg stimulates human mononuclear cells to secrete cytokines, which inhibit the growth of U937 cells and induce their differentiation.

Concepts: DNA, Gene expression, Inhibitor, Food preservation, Freeze drying, Vacuum, Spray nozzle, Unit operations


We have developed a facile single-step synthesis of silver nanocomposite using a conventional spray dryer. We investigated the synthetic conditions by controlling the concentrations of the chemical reactants. Further, we confirmed the effect of the molecular weight of polyvinylpyrrolidones, and revealed that the molecular weight significantly affected the properties of resultant silver nanocomposites. The long-term stability of the silver nanocomposites was tested, and little change was observed, even after storage for three months. Most of all, the simple commercial instrumentation in combination with large-scale synthesis possesses a variety of advantages compared to the conventional complicated and costly dry-process synthesis methods. Thus, our method can be useful for further investigation for both, lab-scale studies and large-scale industry applications.

Concepts: Effect, Molecule, Chemistry, Developed country, Nanomaterials, Nanocomposite, Spray nozzle


The 1st aim of this study is to determine the influence of inlet and outlet air temperatures on the physical and chemical properties of obtained powders from spinach juice (SJ) with 3.2 ± 0.2 °Brix (°Bx). Second, the effect of 3 different drying agents (maltodextrin, whey powder, and gum Arabic) on the same properties was investigated for the selected inlet/outlet temperatures (160/100 °C) which gives the minimum moisture content and water activity values. For this purpose, the total soluble solid content of SJ was adjusted to 5.0 ± 0.2 °Bx with different drying agents. Finally, the effects of different storage conditions (4, 20, and 30 °C) on the physical and chemical properties of spinach powders (SPs) produced at selected conditions were examined. A pilot scale spray dryer was used at 3 different inlet/outlet air temperatures (160 to 200 °C/80 to 100 °C) where the outlet air temperature was controlled by regulating the feed flow rate. Results showed that the moisture content, water activity, browning index, total chlorophyll, and total phenolic contents of the SP significantly decreased and pH and total color change of the SP significantly increased by the addition of different drying agents (P < 0.05). In addition, the changes in the above-mentioned properties were determined during the storage period, at 3 different temperatures. It was also observed that the vitamin C, β-carotene, chlorophyll, and phenolic compounds retention showed first-order degradation kinetic with activation energy of 32.6840, 10.2736, 27.7031, and 28.2634 kJ/K.mol, respectively.

Concepts: Energy, Chemical reaction, Water, Temperature, Solubility, Thermodynamics, Physical property, Spray nozzle


To accelerate the determination of optimal spray drying parameters, a “Design of Experiment” (DoE) software was applied to produce well re-dispersible hesperidin nanocrystals.

Concepts: Food preservation, Spray nozzle


A new precursor, tetrakis(2-methoxyethyl) orthosilicate (TMEOS) was used to fabricate microparticles for sustained release application, specifically for biopharmaceuticals, by spray drying. The advantages of TMEOS over the currently applied precursors are its water solubility and hydrolysis at moderate pH without the need of organic solvents or catalyzers. Thus a detrimental effect on biomolecular drug is avoided. By generating spray-dried silica particles encapsulating the high molecular weight model compound FITC-dextran 150 via the nano spray dryer Büchi-90, we demonstrated how formulation parameters affect and enable control of drug release properties. The implemented strategies to regulate release included incorporating different quantities of dextrans with varying molecular weight as well as adjusting the pH of the precursor solution to modify the internal microstructures. The addition of dextran significantly altered the released amount, while the release became faster with increasing dextran molecular weight. A sustained release over 35days could be achieved with addition of 60 kD dextran. The rate of FITC-Dextran 150 release from the dextran 60 containing particles decreased with higher precursor solution pH. In conclusion, the new precursor TMEOS presents a promising alternative sol-gel technology based carrier material for sustained release application of high molecular weight biopharmaceutical drugs.

Concepts: Oxygen, Solubility, Sol-gel, Pharmaceutical industry, Solvent, Spray drying, Spray nozzle, Nano spray dryer


Inconsistencies in efficacy of ultra-low volume (ULV) ground applications in the literature are linked to the lack of adjustments in sprayer parameters. To investigate the effect of nozzle orientation of a truck-mounted ULV sprayer on application efficacy, a study was conducted at St. Johns County Fairground, Elkton, FL, during the summer of 2014. The efficacy was assessed by mortality of caged adult Aedes aegypti, spray deposition, and droplet size spectrum up to 122 m from the spray line. Aqualuer 20-20 (20.6% permethrin active ingredient [AI] and 20% piperonyl butoxide [PBO]) was applied at the maximum label rate with the nozzle pointed 45° upward, horizontal (0°), or 30° downward. Mortality was recorded after 24 h, deposition was determined with fluorometry, and droplets were measured with DropVision. Overall, horizontal nozzle angle spraying Aqualuer 20-20 achieved the highest efficacy followed by a 30° downward angle, while a 45° angle showed the least efficacy in open field tests. The mortality data showed complete mortality from a 0° nozzle up to 122 m from the spray line except for 1 location at 122 m in 1 replication. The mortality from a 30° downward orientation was lower beyond 30 m from the spray line, while the mortality from a 45° upward orientation was low close to the spray line and beyond 30 m. Horizontal orientation had higher deposition than other orientations, but the differences were not significant. There was also no significant difference in droplet spectrum from all orientations.

Concepts: Statistical significance, Aedes aegypti, Aedes, Pesticide application, Spray nozzle, Aerial application, Sprayer, Spray


Airbrush-assisted cell spraying would facilitate fully arthroscopic filling of cartilage defects, thereby providing a minimally invasive procedure for cartilage repair. This study provides the development and characterisation of custom-made spray nozzles that could serve as a foundation for the development of a BioAirbrush, a platform technology for the arthroscopic application of (cell-laden) hydrogels.

Concepts: Minimally invasive, Invasive, Invasiveness of surgical procedures, Spray nozzle


Enzymes do not have long-term storage stability in soluble forms, thus drying methods could minimize the loss of enzymatic activity, the spray dryer removes water under high temperatures and little time. The aims of this study were to improve the stability of enzymatic extract from Myceliophthora thermophila for potential applications in industry and to evaluate the best conditions to remove the water by spray drying technique. The parameters were tested according to Box-Behnken and evaluated by analysis of variance (ANOVA), all the parameters measured were found to influence the final enzyme activity and spray drying process yield ranged from 38.65 to 63.75%. Enzyme powders showed increased storage stability than extract and maintained about 100% of collagenolytic activity after 180 days of storage at 30°C. The results showed that the microbial enzymes maintained activity during the spray drying process and were stable during long-term storage; these are promising characteristics for industrial applications.

Concepts: Enzyme, Variance, Catalysis, Protease, Analysis of variance, Enzymes, Spray drying, Spray nozzle


The rising demand for pharmaceutical particles with tailored physico-chemical properties has opened new markets for the spray drying technology especially for solubility enhancement, improvement of inhalation medicines and stabilization of biopharmaceuticals. Despite this, the literature on spray drying is scattered and often does not address the fundamental principles underpinning the robust development of pharmaceutical products. It is therefore necessary to present a clearer picture of the field and highlight the principles and factors influencing particle design and scale-up. Areas covered: The review firstly presents a systematic analysis of the trends in development of particle delivery systems using spray drying. This is followed by exploring the mechanisms governing particle formation and the transformations undergone in the various process stages. The next section highlights the particle design factors including those of different equipment configurations and feed/process attributes. Finally, the review summarises the current industrial approaches for scale-up of pharmaceutical spray drying. Expert opinion: The spray drying process provides the ability to directly design particles of the desired functionality. This is of great benefit for the pharmaceutical sector especially as product specifications are becoming more encompassing and exacting. One of the biggest barriers to the spray dried product translation remains one of scale-up/scale-down. A shift from the trial and error approaches of the past to fundamental model-based particle design approaches helps to enhance control over product properties. To this end, process innovations and advanced manufacturing technologies are also particularly welcomed.

Concepts: Pharmacology, Pharmaceutical drug, Drying, Particle, Food and Drug Administration, Spray drying, Spray nozzle, The Rising