• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.77-78
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• 2018

Form-work is a must for construction work. In order to secure the best condition of the form surface and to increase the number of times, the form releasing agent is applied during the process of the form-work. The base oil of the form release agent which has been used already uses the oil which directly or indirectly affects the natural environment and the concrete. In this study, the basic study on the form release agent for concrete was carried out only for the effect of adhesion. The adhesive force of the tile is measured by the mortar to determine the change of the releasing agent and the adhesive strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.969-972
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• 2008

This study investigated the effect of the fundamental condition such as release agent, form conditions and types to the surface of concrete with aluminum form on the various temperatures. On the observation with the naked eyes, coated plywood and aluminum form without a scratch showed similar result, and the surface quality of the concrete with aluminum form was gradually decreased corresponding to the increase of the temperature.For the surface roughness, there is no remarkable tendency according to the temperature. However, the difference in accordance with release agent occurred.As void on the surface corresponding to the various temperature, the micro voids ranged $0.1{\sim}1mm$ were increased corresponding to the increasing temperature, so it was confirmed that the chemical reaction wae accelerated. And the voids of the other range also increased. the fundamental condition such as release agent, form conditions and types

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.47-50
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• 2008

This study analyzed the effect of increasing the number of times using aluminum form to the surface quality of concrete through small sized test, and the result was summarized as following. At the early stage, there was no remarkable change between aluminum and coated plywood form, and the surface quality of concrete both forms slightly declined corresponding with increasing the number of times using.As void on the surface corresponding to the number of times, the voids ranged 0.1~1mm were increased corresponding to increasing the number of times using forms, and the other range voids were also increased according to increasing the number of times using forms. It was confirmed that the surface of concrete was damaged gradually. For comparison with aluminum and coated plywood form though this experimental results, there might be no difference, if release agent was used properly.

• Journal of Pharmaceutical Investigation
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• v.40 no.3
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• pp.181-185
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• 2010

The objective of this study was to improve the extent of drug release as well as the dissolution rate of TD49, a novel algicidal agent, via the preparation of solid dispersion (SD). Among the various carriers tested, $Solutol^{(R)}$ HS15 was most effective to enhance the solubility of TD49. Subsequently, SDs of TD49 were prepared by using $Solutol^{(R)}$ HS15 and their solubility, dissolution characteristics and drug crystallinity were examined at various drug-carrier ratios. Solubili ty of TD49 was increased significantly in accordance with increasing the ratio of $Solutol^{(R)}$ HS15 in SDs. Compared to untreated powders and physical mixtures (PMs), SDs facilitated the faster and greater extent of drug release in water. Particularly, SD having the drug-carrier ratio of 1:20 exhibited approximately 90% of drug release within 1 hr. Differential scanning calorimetry (DSC) thermograms and X-ray diffraction (XRD) patterns suggested that SDs might enhance the dissolution of TD49 by changing the drug crystallinity to an amorphous form in addition to the increased solubilization of drug in the presence of $Solutol^{(R)}$ HS15. In conclusion, SD using $Solutol^{(R)}$ HS15 appeared to be effective to improve the extent of drug release and the dissolution rate of poorly water soluble TD49.

• Archives of Pharmacal Research
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• v.5 no.2
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• pp.61-70
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• 1982

Sulfisoxazole, a chemotherapeutic agent, was microencapsulated with ethylcellulose by means of phase separation form cyclohexane by temperatture change. The size distribution was determined by use of standard sieves and the effect of core to wall ratio was noted. To examine their shapes and usrface characteristics, the microcapsules were observed with a scanning electron microscope. Release of the drug from microcapsules into pH 7.5 buffer medium was studied. The release pattern was found to have similar properties to the release of a drug from an insoluble porous matrix reported. The apparent diffusion coefficient of sulfisoxazole was measured for the transport of the drug from the core of microcapsules into the surronding sink condition. The apparent diffusion coefficient increased with increasing capsule size.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7838-7843
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• 2015

In this study, metformin hydrochloride for first choice of type 2 diabetes patient is administered relatively high dose, 1000 to 2000 mg orally once a day, and had very high water solubility, so it make difficult to swallow tablet to requires high amount of sustained release agent. To overcome these challenges, we used novel metformin salts had relatively low water solubility to minimize sustaining excipient for small size of dosage form. six novel metformin salts were synthesized by making metformin free form under reaction with NaOH and adding acid salts. we confirmed metformin stearate had the lowest water solubility and showed half drug release in dissolution study at 12hour. In conclusion, novel metformin salts had low water solubility can be used to reduce the size of sustained metformin tablet for improving patient compliance.

• Design & Manufacturing
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• v.18 no.3
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• pp.1-8
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• 2024

Macular degeneration is a disease that damages the macula, the center of the retina, and is one of the three major eye diseases along with glaucoma and diabetic retinopathy. The optic nerve and most of the photoreceptor cells are located here, and since this is where images of objects are formed, it is the most important area for vision. The main symptom of macular degeneration is the inability to clearly distinguish the shape of objects or the inability to distinguish colors and light and dark. It is also a serious eye disease that causes black spots in the center of the field of vision. However, it is difficult to distinguish it from the form of vision loss due to presbyopia, so early diagnosis is often missed. The most common treatment for macular degeneration is antibody injection therapy. This treatment requires regular injections once every 1-2 months. When receiving antibody injection therapy, the fear of having to inject directly into the eye and the cost of long-term repeated procedures are a great burden to patients. To overcome these problems, special sustained-release formulations using drug delivery systems are being developed. Since the release speed and release time of the drug can be controlled, the number of times the drug is administered can be drastically reduced. However, the implant (Ø 0.46×6.0mm), which is a sustained-release agent, is manufactured by mixing biodegradable resin (PLGA) and therapeutic agent in a ratio of 4:6, so it is very brittle and there is a high risk of implant damage during handling. In order to safely insert the implant into the eye, a transport device that can be driven with controlled force is required. Therefore, in this study, the lever operating force was measured and analyzed to determine the influence of factors according to the cross-sectional thickness and shape of the linkage produced through injection molding as well as the post-process.

• Archives of Pharmacal Research
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• v.27 no.3
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• pp.314-318
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• 2004

Microglia are the major inflammatory cells in the central nervous system and become activated in response to brain injuries such as ischemia, trauma, and neurodegenerative diseases including Alzheimer's disease (AD). Moreover, activated microglia are known to release a variety of proinflammatory cytokines and oxidants such as nitric oxide (NO). Minocycline is a semi-synthetic second-generation tetracycline that exerts anti-inflammatory effects that are completely distinct form its antimicrobial action. In this study, the inhibitory effects of minocycline on NO and prostaglandin E$_2$ (PGE$_2$) release was examined in lipopolysaccharides (LPS)-challenged BV2 murine microglial cells. Further, effects of minocycline on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression levels were also determined. The results showed that minocycline significantly inhibited NO and PGE$_2$ production and iNOS and COX-2 expression in BV2 microglial cells. These findings suggest that minocycline should be evaluated as potential therapeutic agent for various pathological conditions due to the excessive activation of microglia.

• Journal of Dairy Science and Biotechnology
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• v.23 no.2
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• pp.115-123
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• 2005

Microcapsules consisting of natural, biodegradable polymers for controlled and/or sustained core release applications are needed. Physicochemical properties of whey proteins suggest that they may be suitable wall materials in developing such microcapsules. The objectives of the research were to develop water-insoluble, whey protein-based microcapsules containing a model water-soluble drug using a chemical cross-linking agent, glutaraldehyde, and to investigate core release from these capsules at simulated physiological conditions. A model water soluble drug, theophylline, was suspended in whey protein isolate (WPI) solution. The suspension was dispersed in a mixture of dichloromethane and hexane containing 1% biomedical polyurethane. Protein matrices were cross-linked with 7.5-30 ml of glutaraldehyde-saturated toluene (GAST) for 1-3 hr. Microcapsules were harvested, washed, dried and analyzed for core retention, microstructure, and core release in enzyme-free simulated gastric fluid (SGF) and simulated intestinal fluid(SIF) at $37^{\circ}C$. A method consisting of double emulsification and heat gelation was also developed to prepare water-insoluble, whey protein-based microcapsules containing anhydrous milkfat (AMF) as a model apolar core. AMF was emulsified into WPI solution (15${\sim}$30%, pH 4.5-7.2) at a proportion of 25${\sim}$50%(w/w, on dry basis). The oil-in-water emulsion was then added and dispersed into corn oil ($50^{\circ}C$) to form an O/W/O double emulsion and then heated at $85^{\circ}C$ for 20 min for gelation of whey protein wall matrix. Effects of emulsion composition and pH on core retention, microstructure, and water-solubility of microcapsules were determined. Overall results suggest that whey proteins can be used in developing microcapsules for controlled and sustained core release applications.

• Journal of Pharmaceutical Investigation
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• v.36 no.4
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• pp.271-276
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• 2006

Felodipine, a calcium-antagonist of dihydropyridine type, is a poorly water soluble drug and has very low bioavailability. As preceding studies, use of solid dispersion systems and surfactants(solubilizers) has been suggested to increase dissolution and to improve bioavailability of felodipine. But in case of solid dispersion systems, large amount of toxic organic solvents should be used and manufacturing process time become longer than conventional process. In case of using surfactants, as time elapsed, decreasing of dissolution rate of felodipine due to crystallization has been reported. In this study, Copovidon as a hydrophilic polymer and $Transcutol^{\circledR}$ as a surfactant were combined to formulations if order to increase dissolution of felodipine and conventional wet granulation process were applied to manufacturing of formulations. The effect of Copovidon and $Transcutol^{\circledR}$ on the dissolution oi felodipine was investigated in-vitro. When Copovidon and $Transcutol^{\circledR}$ used simultaneously, the dissolution rate of felodipine was prominently increased compared with when used separately and the maximum increase in the dissolution of felodipine was 5.8 fold compared to control. This is most probably due to synergy effect by combination of Copovidon and $Transcutol^{\circledR}$. Felodipine sustained release tablets were successfully formulated using several grades of HPMC as a release retarding agent. The stability of felodipine sustained release tablet was evaluated after storage at accelerated condition($40^{\circ}C/75%\;RH$) for 6months in HDPE(High density polyethylene) bottle. Neither significant degradation nor change of dissolution rate for felodipine was observed after 6months. In conclusion, felodipine sustained release tablet was successfully formulated and dissolution of felodipine, poorly water soluble drug, was prominently increased and also stability was guaranteed by using combination system of hydrophilic polymer and surfactant.