Spray drying of fenofibrate loaded nanostructured lipid carriers

The conversion of aqueous dispersion of nanostructured lipid carriers(NLCs) into dry powder by spray drying could be a useful approach to render NLCs with better physical chemical stability than the aqueous dispersion. In this study, aqueous NLC dispersion containing fenofibrate was converted into dry, easily reconstitutable powder using spray drying. A central composite face centered design(CCFD) was used to investigate the influence of the ratio of lipid to protectant(mannitol and trehalose) and crystallinity of spray-dried powder on the particle size, yield and residual moisture content of the dried powder. A linear relationship(R2= 0.9915) was established between the crystalline content of the spray-dried powders against the ratio of mannitol to trehalose from 3:7 to 10:0(w/w). Spray drying of NLC aqueous dispersion using a mannitol and trehalose mixture resulted in an increase in particle size of the NLCs after reconstitution in water as compared to that in the initial aqueous dispersion. The decrease in crystallinity of the dry powder by reducing the ratio of mannitol to trehalose could improve the reconstitution of the NLCs in water. However the yield and residual moisture content of dry powder decreased with an increase in the ratio of mannitol to trehalose. Lipid nanoparticles were able to retain the drug incorporation and the prolonged drug release profile after spray drying. The experimental model was robust, and suggested that spray drying is a viable technique for the conversion of NLCs into dry powder.

Studies on the spray dried lactose as carrier for dry powder inhalation

The purpose of this study was to investigate the spray dried lactose as carrier for dry powder inhalation(DPI).The lactose particles were prepared by spray drying,then the particle size,shape and crystal form were characterized by laser diffraction,scanning electron microscopy(SEM),X-ray diffraction(XRD)and differential scanning calorimetry(DSC).The spray dried lactose particles were spherical and amorphous,but would transfer to crystal form when storage humidity was above 32%.Thus,the humidity of the storage environment should be controlled below 30%strictly in order to maintain the amorphous nature of spray dried lactose which is a great benefit to DPI development.

A General Strategy for Efficiently Constructing Multifunctional Cluster Fillers Using a Three-Fluid Nozzle Spray Drying Technique for Dental Restoration

Multifunctional fillers are greatly required for dental resin composites(DRCs).In this work,a spray dryer with a three-fluid nozzle was applied for the first time to construct high-performance complex nanoparticle clusters(CNCs)consisting of different functional nanofillers for dental restoration.The application of a three-fluid nozzle can effectively avoid the aggregation of different nanoparticles with opposite zeta potentials before the spray drying process in order to construct regularly shaped CNCs.For a SiO_(2)–ZrO_(2) binary system,the SiO_(2)–ZrO_(2) CNCs constructed using a three-fluid nozzle maintained their excellent mechanical properties((133.3±4.7)MPa,(8.8±0.5)GPa,(371.1±13.3)MPa,and(64.5±0.7)HV for flexural strength,flexural modulus,compressive strength,and hardness of DRCs,respectively),despite the introduction of ZrO_(2) nanoparticles,whereas their counterparts constructed using a two-fluid nozzle showed significantly decreased mechanical properties.Furthermore,heat treatment of the SiO_(2)-ZrO_(2) CNCs significantly improved the mechanical properties and radiopacity of the DRCs.The DRCs containing over 10%mass fraction ZrO_(2) nanoparticles can meet the requirement for radiopaque fillers.More importantly,this method can be expanded to ternary or quaternary systems.DRCs filled with SiO_(2)-ZrO_(2)-ZnO CNCs with a ratio of 56:10:4 displayed high antibacterial activity(antibacterial ratio>99%)in addition to excellent mechanical properties and radiopacity.Thus,the three-fluid nozzle spray drying technique holds great potential for the efficient construction of multifunctional cluster fillers for DRCs.

Preparation of high emissivity NiCr_2O_4 powders with a spinel structure by spray drying

Spray-drying was used to produce the high emissivity NiCr2O4 powders with a spinel structure. Preliminary investigations focused on fabricating the high emissivity powders for infrared radiation coatings and finding the relationship between microstructure and emissivity. The NiCr2O4 powders were characterized for composition, microstructure, and infrared emissivity by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, infrared radiant instrument, and Fourier transform infrared spectra （FT-IR）. Thermogravimetry and differential thermal analysis show that the appropriate baking temperature for NiCr2O4 powder preparation is about 1200？C. The emissivity measurement and FT-IR spectra show that, because of the special spinel structure, the NiCr2O4 powders have a high emissivity about 0.91. Spray-drying is a suitable method to produce the high emissivity ceramic powders.

Structural and functional properties of hydrolyzed/glycosylated ovalbumin under spray drying and microwave freeze drying

Ovalbumin(OVA),the main protein in egg white,affects most of the functional properties of egg white protein in food processing.The aim of this study was to investigate the effects of spray drying(SD)and microwave freeze drying(MFD)on the preparation of hydrolyzed/glycosylated ovalbumin(HGOVA)and provide useful information on the applications of egg protein powders in the food industry.Results demonstrated that the structure of HGOVA was considerably changed,and its functional properties were improved compared with those of native OVA.SD and MFD processing did not lead to dissociation of HGOVA subunits.SD-HGOVA exhibited higher protein solubility,emulsifying activity,foaming capacities,and gel hardness than MFD-HGOVA.However,MFD-HGOVA was better than the SD-HGOVA in terms of color,emulsion stability,foam stability,water/oil absorption capacity,and thermal stability.Selection of an appropriate drying method could enhance the potential applications of HGOVA in the food industry.

Preparation of dry flowable formulations of Clonostachys rosea by spray drying and application for Sclerotinia sclerotiorum control

A dry flowable formulation of Clonostachys rosea with fungicidal activity against Sclerotinia sclerotiorum was prepared by spray drying. The formulation was optimized by a four-factor, three-level orthogonal experiment to screen inert ingredients and spray-drying conditions. The optimal dry flowable formulation of C. rosea included 30% C. rosea （ratio of conidia powder and its fermentation broth is 1：3）, 3% Morwet EFW, 4% K12, 10% Morwet D425, 9% sodium salt of polynaphthalene sulphonic acid （NNO）, 5% croscarmellose sodium, 5% （NH4）2SO4, 0.5% carboxymethyl cellulose sodium （CMC-Na）, 1% oxalic acid and palygorskite （carrier） up to 100%. The formulation exhibited good physical characteristics, such as high dispersibility, viability and a long shelf life. Plate antagonism tests and pot trials indicated that the dry flowable formulation was very effective against S. sclerotiorum, with control efficiency of up to 88.30%. This dry flowable formulation of C. rosea is a new potential commercial fungicide for spray drying to control S. sclerotiorum.

Optimization of Spray Drying Processing Technology of Mulberry Powder

With concentrated juice of mulberry as raw material, the influence of type and dosage of dry aid, the inlet air tempera- ture, inlet flow rate, and rotating speed on spray drying was studied. The spray drying processing conditions of mulberry pow- der were optimized by the L9 （3^4） orthogonal test on the basis of single factor experiment. The results showed that optimum technical parameters to produce mulberry powder were： lS-cyclodextrin as dry aids with dosage of 30%, inlet air temperature of 180 ℃, rotating speed of 18 000 r/min and inlet flow rate of 30 mL/min. The mulberry powder under this optimum process conditions had a loose structure and bright color, fruity flavor was rich, the anthocyanin content for 54.67 mg/g, moisture content for 5.6% and sensory scores for 83.

Preparation of spherical spinel LiCr_(0.04)Mn_(1.96)O_4 cathode materials based on the slurry spray drying method

Regular spherical chromium doped spinel lithium manganese oxides （LiCr0.04Mn1.96O4） with an average particle size of about 20μm were prepared by the slurry spray drying process. The materials were compared with non-spherical LiCr0.04Mnl.96O4 materials prepared by the common drying process, and all materials were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, laser particle analyzer and Brunaner-Emmett-Teller （BET） specific surface area test. Electrochemical performances of these cathode materials were studied by cyclic voltammetry （CV）, electrochemical impedance spectroscopy （EIS） and Li/LiCr0.04Mn1.9604 battery test. The results show that the spherical active material is single spinel structure, compact, and with narrow particle size distribution and low BET specific surface area. Compared with the non-spherical material, the spherical material prepared by the spray drying process shows a lower electrochemical impedance, a fewer electrochemical polarization and a better charge/discharge rate capability and capacity retention at elevated temperatures.

Synthesis and Characterization of Y_ (0.9-x)Gd_xEu_(0.1)BO_3 Phosphors by Spray Drying Process

Y 0.9-xGd xEu 0.1BO 3 phosphors were synthesized by spray drying (SD) method, and the results were compared with those by conventional solid state (SS) and citrate gel (CG) methods. The PL intensity of phosphors increases with the increase of x value in Y 0.9-xGd xEu 0.1BO 3 (prepared by SD) due to an energy migration process like Gd 3+-(Gd 3+) n-Eu 3+ occurred in the material. Compared with the latter two methods, the phosphor particles prepared by spray drying method have a better morphology, such as homogeneous size (about 1～3 μm) with spherical shape and smooth surface. Furthermore, the spray drying-derived phosphors have higher photoluminescence (PL) intensity than those by citrate gel method, but still a little lower than those by the solid state method.

Preparation and Characterization of Porous Spherical LiFePO_4/C by Spray Drying and Carbothermal Method

The porous spherical LiFePO4/C powders were prepared by spray drying and carbothermal method （SDCTM）. Cheaper trivalent iron ion was used as the precursor. The pure olivine phase can be prepared with the spray drying and subsequent heat-treatment. The average particle size is around 10μm, and the value of porosity is 63.04%. The results indicate that the initial discharge capacity decreases with increasing charge/ discharge rate and reduces from 138.8 mAh · g^-1 at C/20 rate to 98.3 mAh ·g^-1 at 2C rate, while the polarization between the charge and discharge plateaux is enlarged from 53 mv to 347 mv. However, the average discharge efficiency is up to 99.5% at 2C rate compared to 80.6% at C/20 rate from the second cycle.

Structure-dependent re-dispersibility of graphene oxide powders prepared by fast spray drying

The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effectively increase the redispersibility of GOP,but result in a decreased drying efficiency.Herein,we found that the redispersibility of GOP is strongly affected by its microstructure,which is determined by the feed concentration.With the increase of feed concentration,the GO nanosheet assembly varies from the disordered stacking to relatively oriented assembly,making the morphology of the GOP transform from balllike(the most crumpled one)to flakelike(the least crumpled one),and the 0.8 mgml 1 is the threshold concentration for the morphology,structure,and redispersibility change.Once the feed concentration reaches 0.8 mg ml 1,the appearance of the nematic phase in droplet ensures the relatively oriented assembly of GO sheets to form the layered structure with a low crumpling degree,which greatly improves the polar parts surface tension of the solid GOP,making the GOP easier to form hydrogen bonding with water during the redispersion process,thus stabilizing dispersion.This work provides useful information for understanding the relationships between the morphology,microstructure,and final redispersibility of GOPs.

Applying Spray Drying to Customized Powder Manufacture

Spray drying is an important continuous industrial process for drying pumpable liquid formulations irrespective of their heat sensitivity, rheology, solids content and processing rate. Furthermore spray drying has the capability through drying chamber design, plant layout and mode of operation to produce dried products of specific particulate size and morphology. These are important aspects when spray drying technology is applied to the needs of customized powder manufacture. There are many examples in industry where spray dried powders have to meet stringent specifications set by such factors as end-product powder quality standards dictated by global competition,dry raw material characteristics required for optimum downstream processing, and dry materials handling to comply with environmental, health and safety issues. Spray drying is no longer regarded just as a convective industrial drying concept, but also as an integral part of modern manufacturing practices applying powder technology. This paper reviews the aspects of spray dryer design and operation for consideration when customized powder manufacture is involved.

Study on Microcapsulation of Onion Oil with Complex Coacervation and Spray Drying Method

[Objective] The aim was to study the microcapsulation of onion oil with double place separation-coacevation and spray drying. [Method] The effect of processing parameters which included the different wall material combination,the ratio between the wall material,the core material content and the feed concentration on the efficiency and yield of microencapsulated was evaluated by single factor experiments. [Result] Through orthogonal optimization experiments, the optimum condition was as follows: the ratio of Arabic gum and maltodextrin ration was 1∶1, the core content was 25%, feed composition was 18%, and the microencapsulation efficiency and yield can reach 80.7% and 95.3% respectively. [Conclusion] The microcapsulaiton of onion oil with complex coacervation spray drying method can increase membrane thickness, improve core stability and prolong shelf life of products.

Development of Polycaprolactone/Poly(Vinyl Alcohol)/Clay Microparticles by Spray Drying

In this study, nanostructured microparticles was developed with polycaprolactone (PCL), poly(vinyl alcohol) (PVAL) and nanoparticles of the commercial sodium clay NT-25®by using the spray drying technique. The systems obtained were characterized by Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Dynamic Laser Light Scattering (DLS) and Differential Scanning Calorimetry (DSC). The NMR 13C and FTIR techniques showed that both polymers were present in the microparticles and the DSC analysis revealed a small variation in the glass transition temperature of the PCL. The XRD and SEM analyses showed that the microparticles produced were amorphous and had a concave morphology. The NT-25 nanoload reduced the microparticles’ size due to the multiple interactions formed in the hybrid nanocomposite material. Therefore, it was possible to develop microparticles by using biodegradable and biocompatible polymers, with different polarities, allowing the incorporation of hydrophilic and hydrophobic materials and enabling the inclusion of otherwise incompatible materials in the same system.

Heparin Sodium Was Prepared from Pig Intestinal Mucosa by Dialysis and Spray Drying

A method to extract crude heparin sodium from pig intestinal mucosa by dialysis and spray drying was established. The pig intestinal mucosa was treated in the following steps: enzymolysis, resin exchange adsorption-washing, elution, pressure filtration, dialysis, spray drying. Activity of the product was measured using a heparin anti-IIa factor assay kit. The yield of crude heparin obtained by this method was 2.79% higher than that of oven drying method;the production of 1 kg crude heparin sodium saved 43.4 pigs small intestine. The activity was 98.48 ± 2.49 IU/mg (n = 5), 15.18 IU/mg higher than that obtained by oven drying method. The product is pale white powder, attractive color and easy to dissolve.

Microwave Sintering of W-15Cu Ultrafine Composite Powder Prepared by Spray Drying & Calcining-continuous Reduction Technology

The effects of microwave sintering and conventional H2 sintering on the microstructure and properties of W-15Cu alloy using ultrafine W-15Cu composite powder fabricated by spray drying ＆ calcining-continuous reduction technology were investigated. In comparison to the conventional HE sintering processing, microwave sintering to W-15Cu can be achieved at lower sintering temperature and shorter sintering time. Furthermore, higher performances in microwave sintered compacts were obtained, but high microwave sintering temperature or long microwave sintering time could result in coarser microstructures.

Jackfruit Seeds Protein Isolate by Spray Drying Method: The Functional and Physicochemical Characteristics

With increased demand for plant based proteins by the consumers, the food manufacturers appeal for the new plant proteins with predetermined characteristics. This study aims at isolating the protein fraction from jackfruit seeds and characterizing the protein powder for functional and physicochemical properties. The protein part of the seeds was separated through pH treatments and centrifugation process and finally, the concentrate was converted into powder by spray drying method. The functional properties such as solubility, gelling capacity and emulsion properties and the physicochemical properties such as crystallinity, morphology and particle size distribution of the jackfruit seeds protein isolate (JSPI) were studied. The secondary structural elements of JSPI were also determined by Fourier-transform infrared (FTIR) spectroscopy. About 76.89% protein was estimated in the prepared JSPI with 78.44% solubility in an aquatic solvent. The least gelation concentration of JSPI was 12% in a salt solution. The pH of the solvent significantly affected the emulsifying and foaming properties. The protein isolate possessed amorphous structure, moderate bulk density and almost 75% of the particles fell in a similar size distribution range. The conformational study reported that the β-sheet is the dominant secondary structural element with the highest content of 50.28%. The observed features suggest that the JSPI holds satisfactory functional and physicochemical characteristics for being used in protein-enriched foods.

Survival of encapsulated probiotics through spray drying and non-refrigerated storage for animal feeds application

The objective of this study is to verify potential of various types of microorganisms during spray drying and non-refrigerated storage that can be enhanced substantially by selecting suitable protective colloids. Four selected probiotics tested are Lactbacillus plantarum B13 and B18, which are the bacteria probiotics and Kluyveromyces lactis and Saccharomyces blouradii, non-bacteria probiotics. Two levels of experiment occur starting with formulation study of encapsulation agent followed by the viability study of different probiotics after spray dry and two weeks nonrefrigerated storage. The formulation of 30% of gum Arabic, 15% of gelatin and 45% of coconut oil can homogenize well at least for two hours and can produce acceptable dried product (below 4% of moisture content) at low outlet temperature (70℃ -75℃). K. lactis, S. blouradii gives 2.57% and 2.4% of viability percentage after spray drying process and 25.84% and 2.04% after two weeks nonrefrigerated storage respectively. The colonies of non-probiotics bacteria after both conditions are between 1010 and 106 cfu/mL which is among the accepted level for industrial application. However, the survival of probiotics in a spray-dried form during non-refrigerated storage is higher at low of moisture content compared to others.

Microencapsulation by Spray Drying of Vitamin A Palmitate from Oil to Powder and Its Application in Topical Delivery System

Vitamin A palmitate (VAP) contains retinol and palmitic acid which is easily absorbed by body and widely used in skin care products. But, it is a hydrophobic and oxidation sensitive molecule which undergoes rapid degradation especially in an aqueous environment. The purpose of this study was to prepare microcapsules of VAP using combination maltodextrin and modified starches. Emulsion of VAP was prepared using cremophore RH 40 with Tween 80 in a homogenizer and formed emulsion was spray-dried. The spray process was optimized using a central composite design for two variables to obtain microcapsules with desirable characteristics. Microcapsules containing 30% of VAP were produced using different concentration of wall materials. The prepared microcapsules were evaluated for their physical, morphological, in-vitro drug release and SEM study. The results showed that obtained microcapsules are nearly spherical in shape with a particle size ranged from 1 to 12 μm. The drug content and encapsulation efficiency (53% - 63%) of different batches were found within acceptable range. These stabilized drug loaded microcapsules were incorporated into silicone cream based formulation for convenient topical application and evaluated for its physicochemical parameters. The drug release study showed 80.18% to 83.43% of drug release from VAP microcapsules while topical formulations prepared by VAP microcapsules showed 67.09% to 71.45% drug release at the end of 24 hrs. The formulations were kept for 3 months stability study as per ICH guidelines and found to be stable.

Preparation of Microcapsules Containing Grape Polyphenol with the Spray Drying Method Followed by the Layer-by-Layer Method

It was tried to prepare the microcapsules containing grape polyphenol with the spray drying method followed by the layer-by-layer method. As grape polyphenol was water soluble, the spray drying method was adopted to obtain the higher content. As the shell material of the first microcapsules prepared by the spray drying method, palmitic acid with the melting point of 60&degC was adopted in order to prevent grape polyphenol from dissolution into water. As the shell material of the second microcapsules prepared by the layer-by-layer method, chitosan was used to coat the first microcapsules and to give the microcapsules alcohol resistance. In the experiment, the spray drying conditions such as the inlet temperature and the spraying pressure, the oil soluble surfactant species and the chitosan concentration were changed. The mean diameters of microcapsules could be controlled in the range from 5 μm to 35 μm by changing the spraying pressure and the inlet temperature. The yield of microcapsules and the microencapsulation efficiency over 50% could be obtained under the conditions of P = 1.0 kgf/cm2 and Tin = 100&degC. Furthermore, the microencapsulation efficiency could be increased by adding the oil soluble surfactant with the larger HLB value. Coating with chitosan could considerably increase alcohol resistance.