• Journal of Pharmaceutical Investigation
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• v.36 no.1
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• pp.11-17
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• 2006

The objective of this study was to confirm the effect of the type of dissolution media and paddle speed on nifedipine (ND) release profile from osmotic granule and the storage stability. Osmotic granule was manufactured by fluidized bed coating method. At each coating step, morphology of osmotic granule was differed. The size of osmotic granule was $750\;{\mu}m$ at 3 wt% membrane thickness. ND release was changed in diverse dissolution media, paddle speed. ND release is governed by not only osmotic pressure but diffusion from osmotic granule. ND release from osmotic granule decreased as storage period increased. These may be caused by liquid excipient which has low molecular weight. Storage stability of osmotic granule could be improved by removing liquid excipient from semipermeable membrane.

• Archives of Pharmacal Research
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• v.21 no.2
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• pp.113-119
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• 1998

Changes in the release and uptake of glutamate in cerebellar granule and glial cells of offspring of lead-exposed mothers were determined. In cultured cerebellar granule cells exposed to lead for 5 days, glutamate release was less influenced upon N-methyl-D-aspartate (NMDA) stimulation than that in the control. Although the NMDA-stimulated release of glutamate in cerebellar granule cells prepared from lead-exposed first generation pups was not different from that of the control group, the S-nitroso-N-acetylpenicillamine (SNAP)-stimulated release of glutamate in cerebellar granule cells obtained from lead-treated pups was less elevated than that in the control. Furthermore, in cerebellar granule cells obtained from lead-exposed second generations pups, glutamate release did not respond to both NMDA and SNAP stimulation. In cerebellar glial cells exposed to lead, the basal glutamate uptake was not changed. However, the L-trans-pyrollidine-2,4-dicarboxylic acid (PDC)-blocking effects was significantly reduced. In glial cells obtained from lead-exposed pups, the glutamate uptake was also less blocked by PDC than that in the control. Further decreases in PDC-blocking effects were observed in cerebellar glial cells obtained from lead-treated second generation pups compared to those from the control group. These results indicate that lead exposure induces the changes in the sensitivities of the glutamate release and uptake transporter. In addition, these results suggest that lead exposure might affect the intracellular signalling pathway and transmission in glutamatergic nervous system.

• Korean Journal of Environmental Agriculture
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• v.3 no.2
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• pp.9-15
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• 1984

Experiments were carried out with purified technical grade and two types of impregnated and sand-coated granules of carbofuran, in order to investigate the release patterns in water and the persistence of this chemical in soils. The results obtained are summarized as follows: 1) As regards to release velocity in water, impregnated granule was found to be faster than sand-coated granule. The time to reach maximum concentrations of carbofuran in water from technical carbofuran, impregnated granule and sand-coated granule was 0.5, 3 and 5 days, respectively. 2) Degradation rate of carbofuran in soils decreased in the order of technical carbofuran, impregnated granule, sand-coated granule regardless of soil types and application rates. Degradation of carbofuran in flooded soil was faster than in non-flooded soil. Soil flooding appeared to be the main factor in promoting the degradation of carbofuran in the soil. 3) When carbofuran was fortified in soils in the form of technical carbofuran, impregnated granule or sand-coated granule, the persistencies of two terminal residues of carbofuran, that is, 3-hydroxy carbofuran and 3-keto carbofuran decreased in the order of sand-coated granule, impregnated granule and technical form.

• Journal of the Korean Ceramic Society
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• v.56 no.1
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• pp.56-64
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• 2019

Calcium phosphate bone cement was prepared to contain antibiotics for release after setting using granulated ${\beta}$-tricalcium phosphate (${\beta}$-TCP) and hydroxyapatite (HA). Gentamicin sulfate (GS) solution was infiltrated within the interconnected pores of the granule to avoid affecting the setting reaction and for protection of GS during the setting. Consequently, the setting time and the temperature increase were not affected, regardless of the loading of GS. The release of the GS from the cement was estimated by measuring the concentration at regular intervals from the cement dipped solution. The ${\beta}$-TCP granule loaded with GS exhibited the saturation of accumulative concentration at 16 h. In contrast, the HA granule with GS exhibited steady increase in accumulative concentration of over $10{\mu}g/ml$ at 144 h. Thus, the granulated cement could release the GS greater than the minimum inhibitory concentration of staphylococcus during the prescription peroid of the oral antibiotics.

• Biomedical Science Letters
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• v.24 no.3
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• pp.253-262
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• 2018

Platelets are activated at sites of vascular injury via several molecules, such as adenosine diphosphate, collagen and thrombin. Full platelet aggregation is absolutely essential for normal hemostasis. Moreover, this physiological event can trigger circulatory disorders, such as thrombosis, atherosclerosis, and cardiovascular disease. Therefore, platelet function inhibition is a promising approach in preventing platelet-mediated circulatory disease. Many studies reported the involvement of mitogen-activated protein kinases (MAPKs) signaling pathways in platelet functions. However, these studies were limited. Thus, we examined MAPK signaling pathways in human platelets using specific MAPK inhibitors, such as PD98059, SB203580, and SP600125. We observed that these inhibitors were involved in calcium mobilization and influx in human platelets. They also suppressed thrombin-induced ${\alpha}$- and ${\delta}$-granule release. These results suggest that PD98059, SB203580, and SP600125 exhibit $Ca^{2+}$ antagonistic effects.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.211-211
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• 1996

Changes in glutamate release and uptake on cerebellar cells after the chronic exposure to lead were investigated. Rats were received 0.25% lead acetate in drinking water from the beginning of the pregnancy. The control group was given 0.125% sodium acetate in drinking water. The cerebellar cells from 7 or 8 day-old pups were cultured. Amino acid release from cerebellar granule cells and the glutamate uptake into cerebellar glial cells were measured using HPLC-ECD. Basal glutamate release and NMDA-induced glutamate release didn't show significant difference. However, the other amino acids in the granule cells obtained from lead exposed pups were less released than the control after the stimulation by NMDA (50$\mu$M). SNAP-induced (50$\mu$M) glutamate release was significantly reduced in granule cells prepared from lead exposed pups. The basal glutamate uptake in glial cells didn't show any difference. However, the uptake in glial cells prepared from lead exposed pups was significantly less blocked by PDC (24$\mu$M) compared to the control group. These results indicate that lead exposure to the mother might affect the Excitatory amino acid system during the development of the offspring.

• Archives of Pharmacal Research
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• v.23 no.5
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• pp.488-494
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• 2000

Cerebellar granule and glial cells prepared from 7 day-old rat pups were used to investigate the effects of sub-acute nicotine exposure on the glutamatergic nervous system. These cells were exposed to nicotine in various concentrations for 2 to 10 days in situ. Nicotine-exposure did not result in any changes in cerebellar granule and glial cell viability at concentrations of up to 500 $\mu\textrm{M}$. In cerebellar granule cells, the basal extracellular levels of glutamate, aspartate and glycine were enhanced in the nicotine-exposed granule cells. In addition, the responses of N-methyl-D-aspartate (NMDA)-induced glutamate release were enhanced at low NMDA concentrations in the nicotine-exposed granule cells. However, this decreased at higher NMDA concentrations. The glutaminase activity was increased after nicotine exposure. In cerebellar glial cells, glutamate uptake in the nicotine-exposed glial cells were either increased at low nicotine exposure levels or decreased at higher levels. The inhibition of glutamate uptake by L-trans-pyrollidine-2,4-dicarboxylic acid (PDC) was lower in glial cells exposed to 50 $\mu\textrm{M}$ nicotine. Glutamine synthetase activity was lower in glial cells exposed to 100 or 500 $\mu\textrm{M}$ of nicotine. These results indicate that the properties of cerebellar granule and glial cells may alter after subacute nicotine exposure. Furthermore, they suggest that nicotine exposure during development may modulate glutamatergic nervous activity.

• Polymer(Korea)
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• v.29 no.3
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• pp.288-293
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• 2005

Osmotic granule system which is one of the drug delivery systems has been developed to improve manufacturing process and other problems of tablet osmotic systems. It consists of water swellable seed layer, nifedipine drug layer, and drug release controlled membrane layer and manufactured by fluidized bed coater. The granule size and mombrane thickness can be controlled by various amounts of seed and coating solution, respectively. It could be observed that the morphology of osmotic granule was different at each coating step as well as type of coating solution. The bigger the size of granule, the slower the release rate was observed due to decreasing the total specific surface wed of granule. Also, it was observed that the increase of membrane thickness was caused to retard the dissolution of nifedipine due to decreasing the water absorption rate. The drug solubility for dissolution media is greatly affected to nifedipine release. From these results, we assured that osmotic granule can be fabricated by fluidized bed coating methods, and the appropriate release profile could be controlled by the controlling of bead size, membrane thickness and dissolution media.

• Polymer(Korea)
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• v.30 no.2
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• pp.112-117
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• 2006

To improve the type error of osmotic tablet which is one of the drug delivery system, osmotic granule could be manufactured by fluidized bed coating. It has drug layer containing different amount of osmogant and is coated with membrane including different types of binder. We confirmed that the morphology of osmotic granule was different at each coating step. The more mont of osmotic agent, the faster drug release was observed due to increasing the driving force for drug release from osmotic granule. And drug release from osmotic granule coated with membrane using different types of binder was differed by solubility of binders to water. The formation of pore in membrane was confirmed by SEM and DSC Membrane using water soluble binder released more amount of drug. From these results, we assured that difference of osmotic pressure between the inside and the outside of granule and porosity of membrane have an effect on drug release from osmotic granule.

• Archives of Pharmacal Research
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• v.18 no.5
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• pp.295-300
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• 1995

These studies were designed to examine the effects of ginsenosides on glutamate neurotansmission. In primary cultures of rat cerebellar granule cells, ginsenosides (Rb1, Rc did not Rg1, $500\mug/ml$) increased glutamate release which was measured by HPLC. but HPLC, but Re did not shwo an elevation of glutamate release. However, all of these ginsenosides down-regulated N-methyl-D-aspartate (NMDA)-induced glutamate release. Rc strongly increased glutamate release and elevated intracellular clcium concentrations $([Ca_{2+}]_i)$ which was measured by ratio fluorometry with FURA-2AM. These results indicate that ginsenosides have a homeostatic effect on glutamate neurotransmission, and there is a structure-function relationship among the ginsenosides tested.