• Journal of Environmental Science International
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• v.9 no.2
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• pp.173-176
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• 2000

This study was carried out to investigate the filtration characteristics of membrane modules according to hollow fiber dispersion for direct solid-liquid separation of activated sludge. 2 bundle, 4 bundle, and 10 bundle, and 10 bundle module used in this experiment according to hollow fiber dispersion was manufactured at laboratory and permeate flux and transmembrane pressure(TMP) of each module were observed under a suction pressure of 0.5kgf/c$m^2$. As the hollow fibers were dispersed, permeate flux was increased and TMP was decreased. Permeate flux and TMP of each module was 15.0 $\ell$/$m^2$.h and 31.8 cmHg for 2 bundle, 16.0 $\ell$/$m^2$ .h and 17.4 cmHg for 4 bundle, and 20.4 $\ell$/m2 .h and 31.8 cmHg for 10 bundle. In conclusion, the membrane fouling is expected to be decrease by maintaining lower TMP with hollow fiber dispersion.

• Journal of Auto-vehicle Safety Association
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• v.13 no.3
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• pp.13-19
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• 2021

Fog is a phenomenon caused by condensation of water vapor in the atmosphere, which is when very fine drops of water float in the atmosphere and the distance of visible is less than 1km. Fog dispersion technology is a technology that removing or weakening fog by using artificial methods to reduce damage caused by fog. It is applied differently depending on the temperature of fog generation rather than the cause of fog. This study conducted an experimental study on the fog dispersion mechanism in order to minimize damage caused by fog on the road, and studied two methods of over-cooling dispersion using solid-carbon-dioxide as a dissipated particle and dissipating fog particles through thermal acoustic waves. As a result the two methods proved experimentally that were capable of dissipating fog.

• Journal of Pharmaceutical Investigation
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• v.41 no.4
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• pp.217-225
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• 2011

The aim of this work was to prepare porous osmotic pump tablets for controlled delivery of Aceclofenac. Aceclofenac solid dispersion was prepared to improve the solubility by using the drug - carrier (Mannitol) ratio of 1:1. The osmotic pump tablets were prepared using the solid dispersed product of Aceclofenac. The formulation contains potassium chloride as osmotic agent, cellulose acetate as semipermeable membrane, poly ethylene glycol (PEG 4000) as pore former and sodium lauryl sulphate (SLS) as solubility enhancer. The formulations were designed by the general factors such as osmotic agent and pore former. All formulations were evaluated for various physical parameters and, the in vitro release studies were conducted as per USP. The drug release kinetic studies such as zero order, first order, and Higuchi and Korsmeyer peppas were determined and compared. All the formulations gave more controlled release compared to the marketed tablet studied. Numerical optimization techniques were applied to found out the best formulation by considering the parameter of in vitro drug release kinetics and dissolution profile standards. It was concluded that the porous osmotic pump tablets (F7) composed of Aceclofenac solid dispersion/Potassium chloride/Lactose/Sodium lauryl sulphate/Magnesium Stearate (400/40/95/10/5, mg/tab) and coating composition with Cellulose acetate/ PEG 4000 (60/40 %w/w) is the most satisfactory formulation. The porous osmotic pump tablets provide prolonged, controlled, and gastrointestinal environment-independent drug release.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.3 s.234
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• pp.330-339
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• 2005

An experimental study on the behavior of droplets impinging on a solid flat surface was carried out in the present study. Breakup of a liquid droplet impinging on a solid surface has been investigated experimentally for various liquids with different properties. The liquid droplet temperature and incident angle were chosen as major parameters. Liquid droplet temperature and incident angle varied in the range from $-20{\circ}C\;to\;30{\circ}C\;and\;from\;30{\circ}\;to\;60{\circ},$ respectively. It was found that the variation of droplet temperature influences upon the mean diameter and uniformity of droplets which were bounced out from the solid surface. With increase of incident angle the dispersion mass fraction increases, causing the decrease of liquid film flow rate. As the liquid temperature increases, dispersion mass fraction increases since the surface tension decreases.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.866-874
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• 2005

The objective of this study was to elucidate the feasibility to improve the solubility and bioavailability of poorly water-soluble itraconazole via solid dispersions by using supercritical fluid (SCF). Solid dispersions of itraconazole with hydrophilic polymer, HPMC 2910, were prepared by the aerosol solvent extraction system (ASES) under different process conditions of temperature/pressure. The particle size of solid dispersions ranged from 100 to 500 nm. The equilibrium solubility increased with decrease (15 to 10 MPa) in pressure and increase (40 to $60^{\circ}C$) in temperature. The solid dispersions prepared at $60^{\circ}C$/15 MPa showed a slight increase in equilibrium solubility (approximately 27-fold increase) when compared to pure itraconazole, while those prepared at $60^{\circ}C$/10MPa showed approximately 610-fold increase and no endothermic peaks corresponding to pure itraconazole were observed, indicating that itraconazole might be molecularly dispersed in HPMC 2910 in the amorphous form. The amorphous state of itraconazole was confirmed by DSC/XRD data. The pharmacokinetic parameters of the ASES-processed solid dispersions, such as $T_{max},\;C_{max},\;and\;AUC_{0-24h}$ were almost similar to $Sporanox_{\circledR}$ capsule which shows high bioavailability. Hence, it was concluded that the ASES process could be a promising technique to reduce particle size and/or prepare amorphous solid dispersion of drugs in order to improve the solubility and bioavailability of poorly water-soluble drugs.

• Journal of Pharmaceutical Investigation
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• v.30 no.4
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• pp.235-239
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• 2000

Ipriflavone (3-phenyl-7-isopropoxy-4H-1-benzopyran-4-one, IP) is a well-known antiosteoporotic drug with poor bioavailability. In the previous study, we reported that the IP formulation prepared by spray-drying method with polyvinylpyrrolidone (PVP) (SIP) was very effective in improving the bioavailability of IP. In this study, we examined the effects of molecular weight and mixture ratios of PVP to IP on the systemic absorption of IP following oral administration of SIP at a dose of 50 mg/kg to rats. In the effect of molecular weight, the Cmax of spray-dried IP with PVP K30 (SIP-K30) was significantly higher than those of spray-dried IP with PVP 360 (SIP-360), spray-dried IP with PVP K90 (SIP-K90), and spray-dried IP with PVP K17 (SIP-K17) (p<0.05). The AUC of SIP-K30 was about 2, 3, and 5.5 times higher than those of SIP-360, SIP-K90, and SIP-K17, respectively. The AUC value of SIP-K30 was significantly greater than those of SIP-K17 and SIP-K90 (p<0.05) except for SIP-360. In the ratio of PVP K30 to drug, the $C_{max}$ and the AUC value of 3 : 7 IP-PVP solid dispersion were similar to those of 5 : 5 IP-PVP and significantly higher than those of the other solid dispersions (p<0.05). It was concluded that the spray-dried IP with PVP K30 at the ratio of 3:7 (w/w) was the best formulation for improving the bioavailability of IP.

• Journal of Pharmaceutical Investigation
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• v.19 no.2
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• pp.63-69
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• 1989

Dissolution characteristics of indomethacin (IMC) from hydrophobic polymer solid dispersions were investigated. IMC-polyvinyl chloride (PVC) and IMC-ethylcellulose (EC) solid dispersions were prepared. The dissolution patterns of pure IMC, IMC-PVC and IMC-EC solid dispersions prepared at various ratios (1:1, 1:3, 1:5, 1:9 and 1:19 w/w), and those of corresponding physical mixtures were compared. It was found that the dissolution rates of IMC from solid dispersions with PVC or EC decreased in the order of 1:1>1:3>1:5>1:9>1:19 as the drug to polymer ratios decreased. Also the dissolution rates of IMC from EC solid dispersions increased according to flow rate, but PVC solid dispersions were not affected significantly. After all, PVC and EC matrices could be applied in sustained-release preparation of IMC.

• Journal of Pharmaceutical Investigation
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• v.38 no.4
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• pp.249-254
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• 2008

Solid dispersions of poorly water-soluble drug, atorvastatin, were prepared with Eudragit L100 to improve the solubility by spray dryer. To investigate the correlation between physicochemical properties and dissolution rate of solid dispersions, the samples were characterized by scanning electron microscopy (SEM), differential scanning calorimeter (DSC) and fourier transform infrared spectroscopy (FT-IR). SEM and DSC were found that atorvastatin is amorphous in the Eudragit L100 solid dispersion. FT-IR was used to analyze the salt formation by interaction between atorvastatin and Eudragit L100. The dissolution rate of solid dispersed atorvastatin was markedly increased compared to drug powder in stimulated intestinal juice (pH 6.8). Thus, the solid dispersed atorvastatin using the spray drying method with Eudragit L100 may be effective for the bioavailability.

• Polymer(Korea)
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• v.38 no.3
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• pp.272-277
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• 2014

We studied in-line monitoring the dispersion of highly energetic material simulant by a twin screw extruder having a high temperature ultrasonic system. The simulant suspension system consisted of ethylene vinyl acetate and Dechlorane plus 25 as binder and filler, respectively. With increasing filling fraction, the ultrasonic velocity was not changed but the attenuation linearly decreased. It was possible to estimate the solid fraction of well dispersed suspension system by measuring ultrasonic attenuation. The ultrasonic attenuation of samples filled over 60 v% approached straight line with increasing filling fraction when the samples was extruded repeatedly. It was due to the enhanced dispersion of solid particles in the suspension system. It was believed that the degree of dispersion and filling fraction could be obtained by combination of on-line measurement like ultrasonic attenuation and off-line analysis like TGA and SEM with image analyzer.

• Biomedical Science Letters
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• v.25 no.2
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• pp.170-176
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• 2019

The objective of this study was to evaluate the characteristics of the mixtures of choline alphoscerate (alpha-glycerylphosphorylcholine, alpha-GPC), in the liquid form, and sucrose ester, which formed a solid composite. The choline alphoscerate solid composites were prepared using different ratios of sucrose ester, and different preparation methods, such as air drying and rotary evaporation, were compared for their preparation efficacy. We examined the characteristics of the solid composites by using scanning electron microscopy (SEM), angle of repose, and moisture content. The ideal mixing ratio of choline alphoscerate and sucrose ester was determined as 1:3 and air drying was found to be more suitable for the preparation of solid composites than rotary evaporation. SEM measurements of the degree of dispersion and the size of particles indicated that a high-temperature air method was more suitable. These results demonstrated the successful preparation of choline alphoscerate solid composites that have potential for industrial use.