• Journal of Pharmaceutical Investigation
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• v.32 no.1
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• pp.41-45
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• 2002

The purpose of this study is to microencapsulate a highly hygroscopic drug, pyridostigmine bromide (PB), with a waterproof wall material, in order to increase the flowability of the drug particles. Polyvinylacetaldiethylaminoacetate (AEA), Eugragit E and Eugragit RS were examined as the wall materials. Microcapsules containing PB were prepared by the evaporation technique in an acetone/liquid paraffin system using aluminum tristearate as a core material, and evaluated for drug encapsulation efficiency, surface morphology, particle size and drug dissolution. The encapsulation of PB in the wall material was almost complete. Among the wall materials examined, AEA exhibited the most excellency in shape, surface texture, flowability, size distribution of microcapsules. Above results suggest that AEA would be a potential wall material for microcapsulation of highly hygroscopic drugs, such as PB. Through microencapsulation with AEA, inconvenience of handling of PB powders encountered in the process of weighing and packing the powders to tableting die or capsule body could be greatly improved.

• Korean Journal of Plant Resources
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• v.30 no.6
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• pp.612-617
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• 2017

The preservation of pear germplasm, like that of other clonal germplasms, is difficult because it requires conservation of whole plants or their tissues. Among the currently available methods for long-term conservation of clonal germplasm, cryopreservation of shoot tips is the most reliable and cost- and space-effective option. Alginate-coated axillary shoot tips from in vitro-grown pear were conserved successfully in liquid nitrogen (LN) following dehydration. Shoot recovery from cryopreserved shoot tips was improved greatly after 8 weeks of cold acclimation, but recovery decreased slightly after then. The highest regeneration rate was observed when in vitro shoot tips were preincubated in MS (Murashige and Skoog) medium with 0.3 M sucrose for 48 h, and when alginate-coated shoot tips were precultured in MS medium with increasing sucrose concentrations (0.5 M and 0.7 M) for 8 and 16 h, respectively. When the encapsulated beads were dehydrated for up to 7 h [25% water content (fresh weight basis)] under laminar flow, the highest regeneration rate was observed in "BaeYun No. 3" (55.7%) and "Whanggeum" (43.3%) after warming from LN. This technique is useful as a practical procedure to cryopreserve plant material that is sensitive to freezing of the surrounding cryoprotectant medium. Therefore, this technique appears to be promising for the cryopreservation of shoot tips from in vitro-grown plantlets of pear germplasm.

• Polymer(Korea)
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• v.31 no.3
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• pp.215-220
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• 2007

The control of the surface energy by electrohydrodynamic force provides electrospraying with various potential advantages such as simple particle size control, mono-dispersity, high recovery, and mild processing conditions. The advantages are quite helpful to improve the stability of protein drug and control its release. Herein, the nano-encapsulation of protein drugs using electrospraying was investigated. Albumin as a model protein was processed using uniaxial and co-axial electrospraying, and chitosan, polycaporlactone (PCL), and poly (ethylene glycol) (PEG) were used as encapsulation materials. The major processing parameters such as the conductivity of spraying liquids, flow rate, the distance of electrical potential gradient, etc were measured to obtain the maximum efficiency. In the chitosan systems, mean particles size decreases as flow rate and the distance between nozzle and the collecting part decreases. In the uniaxial technique of the PCL systems, mean particles size decreases as flow rate decreases. In the coaxial technique of the PCL systems, it was found that the particles size gets larger under the application of the higher ratio of inner-to-outer liquid flow rates. The primary particles formed out of an electrospraying nozzle showed narrow particle size distribution, but once they arrived to the collecting part, aggregation behavior was observed obviously. Efficient nano-encapsulation of albumin with PCL, PEG, and chitosan was conveniently achieved using electrospraying at above 12 kV.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.27-31
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• 2009

Top spray-drying method is frequently utilized for flavor encapsulation, but the top spray-dried products frequently suffer from high losses of volatile flavor as the result of a high processing temperature (150-$300^{\circ}C$). In an effort to solve these problems, a low-temperature fluidized-bed granulating method was utilized to encapsulate the flavor. For the encapsulation of sesame oil, oil-in-water emulsions of sesame oil and a mixture of maltodextrin, modified starch, gum arabic, and gellan gum were bottom-sprayed at milder temperatures (70-$100^{\circ}C$) using a fluidized-bed granulator. Sesame oil extracts from microcapsules were obtained via a simultaneous distillation/extraction technique, and the retention of volatile flavor compounds was analyzed via a gas chromatography-mass spectrometry. The retention of volatile flavors of sesame oil per se, spray-dried and fluidized-bed granulated microcapsules after 3-day-storage at $37^{\circ}C$ were 0.8%, 37.2%, and 42.0%, respectively. In addition, the low-temperature fluidized-bed granulation showed higher encapsulation yield and sensory preferences for the application of commercial products (beef rice porridge), as compared to spray drying.

• 한국유가공학회:학술대회논문집
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• 2004.11a
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• pp.17-29
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• 2004

Nanofood can be simply defined as natural polymer particles containing functional food materials in nanoscale that are synthesized by polymerization or emulisification process. They have very uniform diameters in the range of 1 to 100 nm and extensive surface areas due to the small particle size in spite of their non-porosity. Although the technique to produce nanofood has not Bong developing history, many works have been achieved in various fields. Nanofood has a lot of special advantages, such as functionality, diversity, applicability, etc. In case of the domestic food industries, however, the accumulation of related technique is insufficient against developed countries except used food materials. Also, it is difficult to acquire technical know-how from the developed countries that possess those technologies. We have been studied on preparing functional nanofood and developing new production processes since 1999. Last 5 years we have laid the foundation on the preparation of nanofood and now are focusing on developing new processes of nanofood and expending the field of its applications.

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3208-3212
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• 2012

Controlled drug delivery systems employing microparticles offer lots of advantages over conventional drug dosage formulations. Microencapsulation technique have been conducted with biodegradable polymers such as poly(lactic-co-glycolic acid) (PLGA) and poly(lactic acid) (PLA) for its adjustable biodegradability and biocompatibility. In this study, we evaluated two techniques, oil-in-water (o/w) emulsion solvent evaporation and spray drying, for preparation of polymeric microparticles encapsulating a newly synthesized drug, SS-AG20, for the long-term drug delivery of this low-molecular-weight drug with a very short half-life. Drug-loaded microparticles prepared by the solvent evaporation method showed a smoother morphology; however, relatively poor encapsulation efficiency and drastic initial burst were discovered as drawbacks. Spray-dried drug-loaded microparticles had an imperfect surface with pores and distorted portions so that its initial burst was critical (70.05-87.16%) when the preparation was carried out with a 5% polymeric solution. By increasing the concentration of the polymer, the morphology was refined and undesirable initial burst was circumvented (burst was reduced to 35.93-74.85%) while retaining high encapsulation efficiency. Moreover, by encapsulating the drug with various biodegradable polymers using the spray drying method, gradual and sustained drug release, for up to 2 weeks, was achieved.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.2
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• pp.115-125
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• 2012

Application of the Object-oriented Programming (OOP) method to the Finite Element Model (FEM) program has various strengths including the features of encapsulation, polymorphism and inheritance. However, this technique should be based upon a premise that the independency of the object method and data to be used is guaranteed. By attempting to apply the OOP to the FEM, existing researches go against the independency of the OOP which is an essential feature of the method. The reason is this: existing researches apply the OOP to modules in accordance with analysis procedures, although the data to be used is classified as an element unit in the FEM. Therefore, the required independency cannot be maintained as whole stiffness matrices and boundary conditions are combined together. Also, solutions are sought from analysis module after data is regrouped at the pre-processor, and their results are analyzed during the post-processor. As this is similar to a batch processing, it cannot use data at analysis, and recalculation should be done from the beginning if any condition is changed after the analysis is complete, which are limitations of the existing researches. This research implemented the Object-orientation of elements so that the three features of the OOP (i.e. encapsulation, polymorphism and inheritance) can be guaranteed and their independency maintained as a result. For this purpose, a model called 'Object-oriented Finite element Model ensuring the Independency of Elements (OFMIE)', which enables the analysis of targets through mutual data exchanges within instance, was developed. In conclusion, the required independency was achieved in the instance of the objected elements and the analysis results of previous conditions could be used for the analysis after changes. The number of repetitive calculations was reduced by 75 per cent through this gradual analysis processes.

• KSBB Journal
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• v.19 no.3
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• pp.178-186
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• 2004

The aim of this study was to investigate the skin-whitening effect of okyong-san and to develop new drug delivery carrier The extracts of okyong-san were found to have the whitening effect and Eudragit$\^$ⓡ/ L 100-55 (EUD) coated solid lipid nanoparticle (E-SLN) was prepared by solvent evaporation method and melt dispersion technique. As a result, E-SLN have a 144-170 nm of particle size, spherical shape, and 33-41% encapsulation efficiency, After release test in vitro, release profile of E-SLN depended on pH and temperature. Lastly, closed patch test and skin-whitening test was peformed clinically. In conclusion, test sample had non-stimulation and high % whiteness. The results suggest that okyong-san and E-SLN is useful as cosmeceuticals for whitening cosmetics.

• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.129-137
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• 2015

The study of photocatalysis of nano titanium dioxideon the cotton fabrics have been investigatedthrough self-cleaning properties. The mini-emulsion technique was employed to prepare the encapsulation of titanium dioxide nano particles in polystyrene beads prior used. The mini-emulsion was coated on the cotton fabrics using Pad-dry method.The loading amount of TiO2particles into the mini-emulsion were various from 1%wt to 40%wt. The particles sizes of the TiO2-encapsulated polystyrene mini-emulsion were investigated by dynamic light scattering. It was noticed that the particle size of the mini-emulsion was in the range of 100- 200 nm. The morphology of treated cotton fabrics were investigated using scanning electron microscopy. The crystal structure of TiO2-encapsulated PS mini emulsion which coated on cotton fabrics were examined by X-ray diffraction spectroscopy. In order to investigate the photocatalytic activities of TiO2 through the selfcleaning characteristics of the cotton fabrics, colorant stains were created on the samples. Coffee stains were used as colorant organic stains. The result shown that the coffee stained on the cotton fabrics significantly showed the improving of the self-cleaning properties under UV radiation.

• Bulletin of the Korean Chemical Society
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• v.27 no.1
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• pp.65-70
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• 2006

An amperometric glucose biosensor has been developed based on the use of the nanoporous composite film of sol-gel-derived zirconia and perfluorosulfonated ionomer, Nafion, for the encapsulation of glucose oxidase (GOx) on a platinized glassy carbon electrode. Zirconium isopropoxide (ZrOPr) was used as a sol-gel precursor for the preparation of zirconia/Nafion composite film and the performance of the resulting glucose biosensor was tuned by controlling the water content in the acid-catalyzed hydrolysis of sol-gel stock solution. The presence of Nafion polymer in the sol-gel-derived zirconia in the biosensor resulted in faster response time and higher sensitivity compared to those obtained at the pure zirconia- and pure Nafion-based biosensors. Because of the nanoporous nature of the composite film, the glucose biosensor based on the zirconia/Nafion composite film can reach 95% of steady-state current less than 5 s. In addition, the biosensor responds to glucose linearly in the range of 0.03-15.08 mM with a sensitivity of 3.40 $\mu$A/mM and the detection limit of 0.037 mM (S/N = 3). Moreover, the biosensor exhibited good sensor-to-sensor reproducibility (~5%) and long-term stability (90% of its original activity retained after 4 weeks) when stored in 50 mM phosphate buffer at pH 7 at 4 ${^{\circ}C}$.