• Journal of Pharmaceutical Investigation
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• v.15 no.4
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• pp.186-197
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• 1985

Polymorphs of piperacillin monohydrate were prepared by various sedimentation methods from piperacillin base for the purpose of developing piperacillin preparations for oral use. Solubility and dissolution rate of each form of the polymorphs were compared with each other. It was found that Form IV showed the highest solubility and the fastest dissolution rate among four forms of polymorphs. In general, the solubility and dissolution rate of two amorphous forms, Form IV and II were higher than those of two crystal forms, Form I and III. The apparent dissolution rates in the artificial gastric juice within 60 minutes were $0.65{\times}10^{-6}mole{\cdot}min^{-1}\;cm^{-2}$ for From IV, $0.36{\times}10^{-6}mole{\cdot}min^{-1}{\cdot}cm^{-2}$ for From II, $0.30{\times}10^{-6}mole{\cdot}min^{-1}{\cdot}cm^{-2}$ for From III and $0.18{\times}10^{-6}mole{\cdot}min^{-1}{\cdot}cm^{-2}$ for From I, respectively.

• Restorative Dentistry and Endodontics
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• v.18 no.2
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• pp.497-500
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• 1993

Sealapex was compaired with a zinc oxide eugenol sealer over a 24 - wk interval to examine solubility in an in vitro situation. After obturation with gutta percha and the appropriate sealer, speciemens were immediately immersed in a saline solution to challenge the solubility of the sealers. The solutions were changed weekly to allow for a continued dissolution of the sealers. After immersed in methylene blue solution for 3 days, the speciemens were made transparent by a clearing process. Microscopic examination was used to determine the linear penetration of dye for each speciemen. Result revealed that sealapex had no greater dissolution than ZOE(P<0.05).

• Korean journal of food and cookery science
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• v.15 no.2
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• pp.163-170
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• 1999

To investigate the effect of adding sugars and lipids on characteristics of cooked rice, the solubility, swelling power, blue value, amylogram and sensory evaluation characteristics of cooked rices with 0.5, 1.0, 1.5, 2.0% level of sugars and lipids additives were measured. The solubility, swelling power and blue value of cooked rice with sugars were increased as the more sugars were added. Those parameters of the cooked rice with isomalto oligosaccharide were higher than sucrose. The solubility decreased as the more lipids were added. The swelling power decreased as the more lipids were added. As the result of amylograph analysis, addition of isomalto oligosaccharide accelerates the gelatinization and retards the retrogradation. In sensory evaluation, the cooked rice with 0.5% level of sucrose and isomalto oligosaccharide were showed better acceptability than the others. In conclusion, the additions of sugars and lipids affect characteristics of cooked rice. Especially, the cooked rice with 0.5% isomalto oligosaccharide was showed the best physiochemical and sensory properties.

• Journal of Pharmaceutical Investigation
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• v.40 no.6
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• pp.339-345
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• 2010

Fenofibrate has been used for many years to lower cholesterol levels and its pharmacokinetic profile is well understood. However, due to its low solubility in water, it has low bioavailability after oral administration. In order to improve the dissolution rate, fenofibrate was formulated into a self-microemulsifying drug delivery systems (SMEDDS). We used pseudo-ternary phase diagrams to evaluate the area of microemulsification, and an in vitro dissolution test was used to investigate the dissolution rate of fenofibrate. The optimized formulation for in vitro dissolution assessment consisted of Lauroglycol FCC (60%), Solutol HS 15 (27%), and Transcutol-P (13%). The mean droplet size of the oil phase in the microemulsion formed from the SMEDDS was about 130 nm. The dissolution rate of fenofibrate from SMEDDS was significantly higher than that of the reference tablet. Our studies suggested that the fenofibrate containing SMEDDS composition can effectively increase the solubility and oral bioavailability of poorly water-soluble drugs.

• Journal of the Korean Applied Science and Technology
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• v.6 no.1
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• pp.59-66
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• 1989

Inclusion complex formation of octyldimethyl p-aminobenzoate with ${\beta}-cyclodextrin$in aqueous solution and in the solid state was studied by the solubility method, spectroscopic (UV, FT-IR) and X-ray diffractornetry. The solid complex of octyldimethyl p-aminobenzoate with ${\beta}-cyclodextrin$ was obtained in molar ratio of 1:2 (guest/host). A spatial relationship between host and guest molecule was clearly reflected in the magnitude of the apparent stability constant (K') and in the stoichiometry of the inclusion complex. Furthermore, a typical type Bs phase-solubility diagram was obtained for octyldimethyl p-aminobenzoate and ${\beta}-cyclodextrin$ in water at $25^{\circ}C$. The results indicated that the solubility of the guest molecule was higher by the formation of ${\beta}-cyclodextrin$ inclusion complex.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2797-2800
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• 2010

For the purpose of developing advanced new absorbents for carbon dioxide, ionic liquids (ILs) are considered as alternative materials due to their superior properties to conventional organic solvents. Since low $CO_2$ solubility in ionic liquids is a major concern for their application as absorbents, it is essential to focus on improving $CO_2$ absorbing capability of ILs. In this paper, strongly basic ionic liquids, namely [$C_n$-mim]OPh (n = 2, 4, 6), have been synthesized and studied over a wide range of temperature and pressure changes. [$C_n$-mim]OPh can be easily synthesized from corresponding [$C_n$-mim]Cl and sodium phenoxide and has been found to be good $CO_2$ absorbents.

• Journal of the Korean Society of Safety
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• v.7 no.1
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• pp.13-19
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• 1992

Supercritical fluid technology was applied to the regeneration of industrial catalyst contaminated with toxic materials. The regeneration process of activated loaded with phenol was proposed, then the adsorphon tower was packed with the activated carbon-bed. Phenol diffuses into supercritical carbon dioxide(SCC) through the micro-pore and voldge of the activated carbon. The saturated solubility of phenol in SCC depended on the density of SCC varing with temperature and pressure conditions. Therefore, the fasile phase equilibrium calculation model of dxpanded liquid One was proposed, and equilibrium solubility of phenol in SCC was calculated using the model theoretically. The regeneration mechanism of activated carbon was analysed by degree of saturation of phenol and diffusion in SCC. The solubility prediction was more satisfactory for the wide range of SCC density than the dense gas model and the desorption of phenol depended on the degree of saturation of phenol in SCC.

• Corrosion Science and Technology
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• v.7 no.4
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• pp.237-242
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• 2008

Physical properties of water, such as dielectric constant and ionic product, significantly vary with the density of water. In the supercritical conditions, since density of water widely varies with pressure, pressure has a strong influence on physical properties of water. Dielectric constant represents a character of water as a solvent, which determines solubility of an inorganic compound including metal oxides. Dissociation equilibrium of an acid is also strongly dependent on water density. Dissociation constant of acid rises with increased density of water, resulting in drop of pH. Density of water and the density-related physical properties of water, therefore, are the major governing factors of corrosion and environmentally assisted cracking of metals in supercritical aqueous solutions. This paper discusses importance of "physical properties of water" in understanding corrosion and cracking behavior of alloys in supercritical water environments, based on experimental data and estimated solubility of metal oxides. It has been pointed out that the water density can have significant effects on stress corrosion cracking (SCC) susceptibility of metals in supercritical water, when dissolution of metal plays the key role in the cracking phenomena.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.253-260
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• 2002

Chemical weathering processes related with mineralogical characters and ground water condition are very essential engineering problems in soluble rock masses. Detailed geological mapping were performed and 8 samples were collected from the 2 formations including various rock faces to deduce the possibility of the limestone cavity formation and their mechanism. Petrological descriptions and various petro-mineralogical experiments such as XRD analysis, clay mineral analysis, absorptivity test, impurity analysis were conducted to evaluate the cavity making processes. Laboratory solubility test for rock specimen were also carried out under the strong acid (pH=1) condition. From the experimental data and geological mapping data, it is found that the formation of limestone cavities in limestones are strongly related with geological structures such as beddings, cleavages and the contents of impurities rather than CaCO$_3$contents. In case of dolomites, rock textures, grain size, amounts and types of clay minerals as well as geological structures are major controlling factors of cavity forming processes

• Journal of the Korean institute of surface engineering
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• v.23 no.4
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• pp.225-229
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• 1990

Solubility Products of metal oxides, such as Al2O3 and UO2 in KCl-LiCl eutectic composition was calculated by using an exact an exact thermodynamic. The values for Al2O3 ThO2 and UO2 were found to be 2.51$\times$10-27, 4.97$\times$10-15and 2.17$\times$10-12in mole per liter basis at 743 K, respectively. The correlation of theoretical values with those of experiment were in good agreement. It is worth to note that the exact cycle method was proved to be satisfactory in making predictions of solubillities and also solubility products of sparingly soluble metal oxides in an ionic salt system.