• Journal of Pharmaceutical Investigation
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• v.33 no.2
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• pp.121-127
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• 2003

The objective of this study was to solidify the simvastatin self-microemulsifying drug delivery system (SMEDDS) and to improve the encapsulation efficiency of solidified alginate beads using sodium alginate. Typical simvastatin SMEDDS was composed of various oils, surfactants and cosurfactants. Also solidified-alginate beads was prepared by crosslinking liquid emulsion mixtures containing sodium alginate and other excipients (cetylpyridinum chloride (CP-Cl), hydroxypropyl methylcellulose, starch and so on). in $CaCl_2$ solution, it has been investigated that the drug release pattern and encapsulation efficiency were varied with the ratio of cationic lipid (CP-Cl). Solidified sodium alginate beads containing simvastatin SMEDDS were redispersed into media without re-aggregation. Oil droplet size of redispersed solidified-beads in media produced smaller than the initial size. The density of beads and drug loading amount were increased with increasing cationic lipid content. These systems have advantages of storage stability and predictability of drug release rate.

• Korean Journal of Animal Reproduction
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• v.20 no.2
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• pp.197-205
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• 1996

This study was conducted to examine the effect of sustained release recombinant bovine somatotropin(SR-rBST) with different dosage(0, 0.03mg/kg body weight/14 day, 0.06mg/kg body weight/14 day, 0.09mg/kg body weight/14 day) on the economical traits of the semen characteristics and sexual behaviors and blood chemical values with sixteen Holstein dairy young bulls in Dairy Cattle Improvement Center of National Livestock Co-operatives Federation. Sensual testings of collected semens of Holstein young bulls were not different among treatments (p>0.05). Ejaculated semen volumes of control, SR-rBST 0.03mg, 0.06mg and 0.09mg groups were 5.6ml, 5.6ml, 6.0ml and 6.7m, respectively, but the result of SR-rBST 0.09mg group significantly increased semen volume(P<0.05). In sperm concentration, SR-rBST 0.06mg and 0.09mg groups significantly increased the total number of sperms than the other groups(P<0.05). In otherwise, SR-rBST treatments did not affect on pH, osmotic pressure, anti forzen rate, abnormality and motility of collected semen during whole experimental period. Reaction time(RT), sexual aggressiveness(SA) and tactile stimulation(TS) were not different among treatments. The libido scores(LS) of control, 0.03mg, 0.06mg and 0.09mg groups were 68.0, 80.5, 73.9 and 80.8, respectively, and LS were significantly improved by SR-rBST administration(P<0.05). The effect of SR-rBST on scrotal circumference measurement that is important factor to determine the ability of semen production, was not different among treatments. These studies indicates that SR-rBST treatments favourably affect on semen quality and sexual libido in Holstein young bull.

• Journal of Pharmaceutical Investigation
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• v.40 no.1
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• pp.9-14
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• 2010

Lacidipine used for the treatment of hypertension has low water solubility and is classified as BCS Class II category. Gelucire-based solid dispersions (SD) containing lacidipine were prepared by solvent evaporation method to enhance drug dissolution. The powdered forms of SD showed irregularly spherical shape. Thermal behaviors of SD from differential scanning calorimetry indicated that distinct endothermic peak of lacidipine ($184^{\circ}C$) was shifted to lower region ($150.1^{\circ}C$). Drug was present in a crystalline form. NMR spectra also showed some molecular interaction between drug and Gelucire. There was no significant difference in DSC and NMR behaviors between Gelucire 44/14 and Gelucire 50/13. The initial dissolution rate of SD-loaded tablet linearly increased both in water and in water containing 1% tween 20, and much higher than the commercial tablet, $Vaxar^{(R)}$. When the amount of SD was increased, the release rate was greater. The Gelucire 50/13 showed higher dissolution than the Gelucire 44/14. The produced solid dispersion with various kinds of excipients and making tablets, it was found that solid dispersions can increase the solubility in artificial gastric juice and finally increases dissolution rate.

• Journal of Adhesion and Interface
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• v.10 no.1
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• pp.11-16
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• 2009

The microcapsules containing rosmarinic acid were prepared in this research. Rosmarinic acid is known that it is effective to care the winkles. Chitosan was used as a wall material, and glutaraldehyde was used as a crosslinking agent, and the microcapsules were prepared by the water-in-oil (W/O) emulsion method. In this method Span80 was used as an emulsifier, and mineral oil was used as a medium material. Perfectly spherical microcapsules were obtained in the size range of $0.5{\sim}0.9{\mu}m$. The effects of emulsifier concentration and stirring speed on the average particle size and distribution, and encapsulation efficiency were investigated. The release behavior of the microcapsules with different amount of the crosslinking agent and different emulsifier concentrations were also investigated.

• Polymer(Korea)
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• v.37 no.3
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• pp.262-268
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• 2013

pH-sensitive P(MAA-co-PEGMA) hydrogel particles were prepared and their feasibility as smart delivery carriers for cosmetic ingredients was evaluated. P(MAA-co-PEGMA) hydrogel particles having an average size of approx. $2{\mu}m$ were synthesized via dispersion photopolymerization. There was a drastic change in the swelling ratio of P(MAA-co-PEGMA) particles at a pH of around 5 due to the ionization of MAA in the hydrogel and as the amount of MAA in the hydrogel increased, the swelling ratio increased at a pH above 5. The P(MAA-co-PEGMA) hydrogel particles showed a pH-sensitive release behavior. Thus, at pH 4 almost none of the albumin permeated through the skin while at pH 6 relatively high skin permeability was obtained. The albumin loaded in the P(MAA-co-PEGMA) hydrogel particles was hardly degraded in the presence of pepsin and its stability was maintained.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.511-516
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• 2005

In this work, the crosslinked-chitosan microcapsules containing fragrant oil were prepared by oil-in-water-in-oil (O/W/O) multi-emulsion method. The effects of concentration of fragrant oil and stirring rates on the preparing of the microcapsules were investigated. The diameter and form of the microcapsules were observed by scanning electron microscope (SEM). As a result, the average particle size of microcapsules was decreased with increasing the stirring rate. The formation of chitosan microcapsules was comfirmed by FT-IR. The inclusion of fragrant oil into chitosan microcapsules was determined in the presence of specific peak of fragrant oil, i.e., $1,460cm^{-1}$, $2,960cm^{-1}$. Also, the release behavior or profile of fragrant oil from chitosan microcapsules was examined with UV/vis spectra. Released amounts of fragrant oil were increased with increasing as the content of fragrant oil and decreasing the pH.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.6
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• pp.717-723
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• 2010

Many researchers have studied woven fabric carbon-fiber-reinforced composite (CFRP) materials but the study of fatigue crack propagation in composites has been insufficient. It has known that the crack propagation behavior differs depending on the load and the fiber direction. In this study, the fatigue crack propagation along two different fiber array directions ($0^{\circ}$, $45^{\circ}$) in plain woven CFRP composite was investigated. Fatigue crack propagation tests were conducted on the woven CFRP composite under a sinusoidal waveform load with stress ratios of 0.1 at a frequency of 10 Hz. Once the results of the tests were obtained, fatigue crack propagation rates (da/dN) were plotted against the energy release rate amplitude (${\Delta}G$), and it was observed that either mode I crack propagation or mixed mode crack propagation occurs depending on the fiber array direction.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.19 no.3
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• pp.147-155
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• 2008

Objectives: The purpose of this study was to evaluate the efficacy and tolerability of osmotic release oral system-methylphenidate (OROS-MPH) in children with attention-deficit hyperactivity disorder (ADHD) and comorbid psychiatric disorders. Methods: This was an 8-week open label study of OROS-MPH monotherapy. The subjects were 113 children with ADHD aged 6-12 years. Outcome measures were the Korean version of the parent ADHD Rating Scale (K-ARS), Korean version of the Conners Parent Rating Scale (K-CPRS), Clinical Global Impression-Severity and Clinical Global Impression-Improvement. Side effects were monitored using Barkley's Side Effect Rating Scale. We compared the change-over-time in the mean scores of the outcome measure according to the comorbidity of disruptive behavior disorder, depressive disorder, anxiety disorder, and tic disorder. Results: The mean K-ARS and K-CPRS scores were significantly decreased, regardless of the comorbidity. The mean doses of OROS-MPH and dropout rate did not differ significantly according to comorbidity. The OROS-MPH was well tolerated, regardless of the comorbidity. However, children with tic disorder reported a higher frequency of tics or nervous movements between the $2^{nd}\;and\;8^{th}$ week than those without tic disorder. Conclusion: The OROS-MPH is effective for decreasing the symptoms of ADHD, and it is well tolerated, even by patients with comorbid psychiatric disorders.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.99-105
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• 2004

When a saturated clay is sampled from a borehole in an undisturbed manner, the exerted negative pore water pressure restricts the volume expansion. The vertical and horizontal stresses to which the clay was subjected in the ground are smaller and larger than this isotropically confining stress equivalent to the mean principal stress in the ground, respectively. Therefore the sample expands vertically and shrinks laterally under an undrained condition. In the ordinary consolidation test, the sample thus deformed is trimmed to fit the inside of the consolidometer ring. Thus, the specimen generates larger consolidation displacement due to confining larger horizontal stress when in-situ effective pressure is loaded. The specimen does not reproduce the in-situ consolidation behavior, In this paper, considering sample deformation, the test specimen is made to expand laterally to fit the inside of the ring in the undrained manner when the in-situ effective pressure is loaded. And applicability of this proposed test procedure was verified; results from the conventional consolidation test procedure are also discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2B
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• pp.93-101
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• 2012

HEC-ResSim, reservoir operation model, is applied to Seomjin river dam in order to establish a rational method for water supply and flood control by dam operation. In order to minimize downstream flood damage for Seomjin river basin and adjacent regions, reservoir routing is applied to several frequency flood events within the framework of rainy seasonal operation rule and then the characteristics change of hydrological behavior for the downstream of study area is investigated in depth. Its quantitative efficiency and estimation method is evaluated on the basis of the adjustment scheme of conservation water surface elevation for flood control and water secure; reservoir routing considering preliminary release and variable restricted water level; and its effect to water supply; and downstream flood-duration analysis.