• 한국임상약학회지
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• 제16권1호
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• pp.63-68
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• 2006

Gabapentin, 1-(aminomethyl-1-cyclohexyl)acetic acid, is anew antiepileptic drug related to ${\gamma}-aminobutyric$ acid(GABA) currently being introduced in therapy worldwide. The bioavailability and pharmacokinetics of gabapentin capsules were examined in 22 volunteers who received a single oral dose in the fasting state by randomized balanced $2{\times}2$ crossover design. After dosing, blood samples were collected for a period of 24 hours and analyzed by liquid chromatography-tandem mass spectrometry (LC/MS/MS). Time course of plasma gabapentin concentration was analyzed with non-compartmental and compartmental approaches. $WinNonlin^{(R)}$, the kinetic computer program, was used for compartmental analysis. One compartment model with first-order input, first-order output with no lag time and weighting by $1/(predieted\;y)^2$ was chosen as the most appropriate pharmacokinetic model for the volunteers. The major pharmacokinetic parameters $(AUC_{0-24hr},\;AUC_{inf},\;C_{max}\;and\;T_{max})$ and other parameters $(K_a,\;K_{el},\;V_d/F\;and\;Cl/F)$ of $Gapentin^{TM}$ (test drug) and $Neurontin^{TM}$ (reference drug) were estimated by non-compartmental analysis and compartmental analysis. The 90% confidence intervals of mean difference of logarithmic transformed $AUC_{0-24hr}\;and\;C_{max}$ were $log(0.9106){\sim}log(1.l254)\;and\;log(0.8521){\sim}log(1.0505)$, respectively. It shows that the bioavailability of the test drug is equivalent with that of the reference drug. There was no statistically significant difference between the two drugs in all pharmacokinetic parameters.

• 대한환경공학회지
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• 제29권12호
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• pp.1381-1389
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• 2007

중금속 폐수는 다양한 유독성 화합물과 함께 배출되므로 상수원, 토양, 지하수 등의 환경에 악영향을 야기 시킬 수 있다. 이러한 고농도의 복합중금속과 시안착염을 포함한 도금폐수 처리 시 일반적으로 잘 알려진 알카리염소법에 의한($1^{st}$ Oxidation: pH 10, reaction time 30 min, ORP 350 mV, $2^{nd}$ Oxidation: ORP 650 mV) 시안의 잔류농도에 대한 제거효율은 유입수의 시안농도 374 mg/L에 비해 처리 후 잔류시안농도는 3.74 mg/L로써 그 제거효율이 99%로써 상당히 높았으나 수질환경보전법상 수질배출허용기준(나 지역) 1 mg/L 이하에 만족하기 위해서는 2차, 3차 등의 고도처리가 요구됨을 알 수 있었고, 이에 아연백법 및 공침처리공정(reaction time: 30 min, pH: 8.0, rpm: 240)을 적용하여 용해되어 잔류하는 시안착염을 불용성염으로 침전시켜 처리한 결과 잔류시안농도가 1.0 mg/L 이하의 만족할 만한 결과를 있었다. 크롬의 처리는 6가 크롬을 3가 크롬으로 환원(pH: 2.0 max, ORP: 250 mV)시킨 후, 수산화물로 처리(pH: 9.5)시 무난히 99%의 최대 제거효율을 얻을 수 있었다. 폐수 중 나머지 동(Cu)과 니켈(Ni)처리는 황화물 응집침전법을 적용한 결과 최적 pH는 $9.0\sim10.0$에서 $Na_2S$의 최적주입량이 Cu의 경우 0.5 mol에서 99.1%, Ni의 경우 3.0 mol에서 99.0% 이상 제거할 수 있었다. 즉 중금속 복합폐수 중 시안착염은 알카리 염소산화처리법만으로는 수질환경보전법의 규제치 이하로 처리가 불가능 하였고 아연백법 및 공침공정을 같이 적용한 결과 규제치 이하로 처리가 가능하다는 것을 현장 확인할 수 있었다.

• Journal of Pharmaceutical Investigation
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• 제41권4호
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• pp.255-262
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• 2011

Method using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was developed and validated for the determination of pregabalin in plasma samples. Acquisition was performed by monitoring the transitions: m/z 160.1${\rightarrow}$142.2 for pregabalin and m/z 423.2${\rightarrow}$207.1 for losartan (as an internal standard). After cold acetonitrileinduced protein precipitation of the plasma samples, separation was performed with C18 column by isocratic mobile phase consisted of 10 mM ammonium acetate and acetonitrile (15:85, v/v). Results were linear over the concentration ranged from 0.1 to $10{\mu}g$/mL and the correlation coefficients (r) were $\geq0.99$. Intra- and inter-day precisions were $\leq6.02$ and $\leq11.04%$, respectively, and intra- and inter-day accuracies were 96.60-101.09 and 98.10-102.60%, respectively. This validated method was successfully applied to a bioequivalence study of two formulations of pregabalin, Daewoong pregabalin capsule (Daewoong Pharm. Co., Ltd.) and Lyrica$^{(R)}$ capsule (Pfizer Korea Ltd.) in twenty eight healthy Korean volunteers. The subjects received a single oral dose of each formulation (150 mg as pregabalin) in a randomized $2{\times}2$ crossover study and plasma samples were obtained from each subject at predetermined time intervals. Then, the pharmacokinetic parameters ($AUC_{0-t}$, $C_{max}$ and $T_{max}$) were calculated and statistically analyzed to assess the differences between two formulations. The 90% confidence intervals for the log-transformed data were acceptable range of log 0.8-log 1.25 (e.g., log 1.0048-log 1.0692 for AUC0-t, log 0.9142-log 1.0421 for $C_{max}$). Thus, $AUC_{0-t}$ and $C_{max}$ met the criteria of the Korea Food and Drug Administration (KFDA) for bioequivalence test indicating that Daewoong pregabalin capsule was bioequivalent to Lyrica$^{(R)}$ capsule.

• 대한의생명과학회지
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• 제11권3호
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• pp.327-332
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• 2005

Sf21 cells become popular as the host permissive cell line to support the baculovirus AcNPV replication and protein synthesis. The cells grow well on TC-100 medium that contains $0.1\%$ D-glucose as the major carbon source, strongly suggesting the presence of endogenous glucose transporters. However, unlike human glucose transporters, very little is known about the characteristics of the endogenoussugar transporter(s) in Sf21 cells. Thus, some kinetic properties of the sugar transport system were investigated, involving the uptake of 2-deoxy-D-glucose (2dG1c). In order to obtain a true measure of the initial rate of uptake, the uptake of $[^3H]2dGlc$ from both low $(100{\mu}M)$ and high (10 mM) extracellular concentrations was measured over periods ranging from 30 sec to30 min. The data obtained indicated that the uptake was linear for at least 2 min at both concentrations, suggesting that measurements made over a 1min time course would reflect initial rates of the jexpse uptake. To determine $K_m\;and\;V_{max}$ of the endogenous glucose transporter(s) in Sf21 cells, the uptake of 2dG1c was measured over a range of substrate concentrations $(50{\mu}M\~10mM)$ 2dG1c uptake by the Sf21 cells appeared to involve both saturable and non-saturable (or very low affinity) components. A saturable transport system for 2dG1c was relatively high, the $K_m$ value for uptake being < 0.45 mM. The $V_{max}$ value obtained for 2dG1c transport in the Sf21 cells was about 9.7-folds higher than that reported for Chinese hamster ovary cells, which contain a GLUT1 homologue. Thus, it appeared that the transport activity of the Sf21 cells was very high. In addition, the Sf21 glucose transporter was found to have very low affinity for cytochalasin B, a potent inhibitor of human erythrocyte glucose transporter

• Biomolecules & Therapeutics
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• 제13권2호
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• pp.118-122
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• 2005

The objective of the present investigation was to study pharmacokinetics of promethazine in Korean healthy subjects using a validated HPLC method. The HPLC analysis was performed on a Capcell Pak CN column with a mixture of acetonitrile-0.02M potassium dihydrogen phosphate (42:58, v/v, pH 6.0) and the analyte was quantified with UV detection at 251 nm. The calibration curve of the drug was linear over the range of 1-40ng/mL in human serum and the limit of quantification (LOQ) was 1 ng/mL. This analytical method was validated and shown to be specific, accurate, precise and reproducible. This method was applied to pharmacokinetic study of promethazine in Korean healthy volunteers following an oral administration of two 25 mg Himazin tablets (50 mg promethazine ${\cdot}$HCI) after overnight fasting. Serum samples were collected at given intervals over a 36-hour period (12 points) and pharmacokinetic parameters were determined from serum concentration-time profile using WinNonlin program. The estimated $AUC_{0__\infty}$, $AUC_{0_\infty}$, $C_{max}$, $T_{max}$ and $t_{1/2}$ of promethazine obtained from Korean healthy subjects were 103.84 ${\pm}$84.30 ng${\cdot}$hr/mL, 87.94${\pm}$81.02 ng${\cdot}$hr/mL, 13.43${\pm}$10.92 ng/mL, 2.00${\pm}$1.16 hr and 5.88${\pm}$3.47 hr, respectively.

• 화약ㆍ발파
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• 제17권1호
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• pp.27-55
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• 1999

The excavation works for deep foundation in urban areas have recently increased complaints of blasting vibration and settlement of ground level. Foundation must be excavated approximately up to 24-28m depths from the surface. The roads and subway line pass through the excavation area. The Dae-chung station is also located at the nearest distance 5-35m from the working site. To protect subway station and adjacient some structures from blasting and settlement, the level of ground vibration, displacements and stress were monitored and analyzed. The results can be summarized as follows ; 1. An empirical particle velocity equation were obtained by test blasts at Nassan Missi 860 Office tel construction site. $V{\;}={\;}K(D/\sqrt{W})^{-n}$, where the values for n and k are estimated tobe 0.371 and 1.551. From this ground vibration equation, the max. charge weight per delay time against distance from blasting point is calculated. Detailed blasting method is also presented. 2. To measure the horizontal displacement in directions perpendicular to the borehole axis, 6 inclinometers installed around working sites. The displacement at the begining was comparatively high because the installation of struts was delayed, but after its installation the values showed a stable trend. Among them, the displacement by 3 inclinometers installed on a temporary parking area showed comparatively high values, for example, the displacement measured at hole No. IC-l recoded the max. 47.04mm for 6 months and at hole No. IC-2 recorded the max. 57.33mm for 7 months. So, all of these data was estimated below a safe standard value 103mm. 3. Seven strain gauge meter was installed of measure the magnitude and change of stress acted on structs. The measured value of maximum stress was $-465{\;}kgf/\textrm{cm}^2,{\;}-338.4{\;}kgf/\textrm{cm}^2,{\;}302.3{\;}kgf/\textrm{cm}^2$ respectively. In compareto the allowable stress level of steel, they are estimated to be safe.

• 약학회지
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• 제37권3호
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• pp.235-242
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• 1993

8-Fluorociprofloxacin(8-FCP) is an investigational quinolone derivative that is substituted with fluorine at the C-8 position of ciprofloxacin(CP). It was found that the in vitro activity of 8-FCP against Gram(+) bacteria was more potent that of CP, but the opposite against Gram(-) bacteria was true. However, 8-FCP showed better in vivo efficacy than CP against representative Gram(-) organisms, E. coli and K pneumoniae. In an attempt to seek for factors causing this discrepancy in the antibacterial activities, a comparative pharmacokinetic study of 8-FCP and CP was conducted in mice and rats treated either intravenously or orally at a single dose of 30 mg/kg. The pharmacokinetic parameters in mice were as follows; the mean peak serum concentrations(C$_{max}$) following i.v. and oral doses were 12.4 and 5.3 $\mu\textrm{g}$/ml for 8-FCP, and 9.5 and 2.5 $\mu\textrm{g}$/ml for CP, respectively. The terminal half-life(t$_{1/2\beta}$) was 72.9 min for 8-FCP, and 98.2 min for CP, and the oral bioavailability(F) was 89.9% for 8-FCP, and 50.5% for CP. In rats, the mean ($\pm$SD) $C_{max}$ after i.v. administration were 11.6$\pm$1.6 $\mu\textrm{g}$/ml for 8-FCP, and 10.2$\pm$1.3 $\mu\textrm{g}$/ml for CP, whereas oral administration produced $C_{max}$ of 5.9$\pm$1.8 $\mu\textrm{g}$/ml for 8-FCP and 1.1$\pm$0.9 $\mu\textrm{g}$/ml for CP, respectively. The t$_{1/2\beta}$ was 67.9$\pm$8.4 min for 8-FCP, and 76.4$\pm$7.2 min for CP. The F was 88.6$\pm$6.3% for 8-FCP, and 40.7$\pm$6.5% for CP. Marked differences were observed between the two quinolones in the $C_{max}$ and the area under the concentration-time curve obtained after oral administration in mice and rats. The extent of 8-FCP absorption in both mice and rats was approximately 2-fold higher than that of CP, suggesting that the fluorine atom attached to C-8 plays an important role in facilitating oral absorption from the gastrointestinal tract.

• 한국미생물·생명공학회지
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• 제47권2호
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• pp.259-268
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• 2019

In this study, the extracellular metalloprotease from Serratia marcescens PPB-26 was purified to homogeneity via ethanol fractionation and DEAE-cellulose column chromatography. Thus, a 3.8-fold purification was achieved with a 20% yield and specific activity of 76.2 U/mg. The purified protease was a 50-kDa monomer whose optimum pH and temperature for activity were 7.5 and $30^{\circ}C$ respectively; however, it was found to remain active in the 5-9 pH range and up to $40^{\circ}C$ for 6 h. The protease had a half-life of 15 days at $4^{\circ}C$, an optimum reaction time of 10 min, and an optimum substrate (casein) concentration of 0.25%. Furthermore, the Michaelis constant ($K_m$) and reaction velocity ($V_{max}$) of the protease were calculated to be 0.28% and $111.11{\mu}moles/(min{\cdot}mg)^{-1}$, respectively. The protease was stable when subjected to metal ions (2 mM), showing increased activity with most (especially $CoCl_2$ and $MgSO_4$ (30.54% increase)). It was also stable when exposed to oxidizing agents, bleaching agents, and detergents (5% v/v for 60 min). It retained 93% of its activity in non-ionic detergents (Tween-20, Tween-80, and Triton X-100). Moreover, wash performance analysis in commercial detergents (Ariel and Tide) showed that not only was the protease capable of protein stain removal, but also reduced cleaning time by 80% when added to detergents. Thus, the Serratia marcescens PPB-26 metalloprotease appears to be a promising new candidate as a laundry additive in the detergent industry.

• The Korean Journal of Physiology and Pharmacology
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• 제20권1호
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• pp.35-39
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• 2016

To conduct a kinetic study of paraquat (PQ), we investigated 9 patients with acute PQ intoxication. All of them ingested more than 20 ml of undiluted PQ herbicide to commit suicide and arrived at our hospital early, not later than 7 h after PQ ingestion. The urine dithionite test for PQ in all of the nine patients was strongly positive at emergency room. Blood samples were obtained every 30 min for the first 2~3 h and then every 1 or 2 h, as long as the clinical progression was stable among the patients for 30 h after PQ ingestion. The area under the plasma concentration-time curve ($AUC_{inf}$), which was extrapolated to infinity, was calculated using the trapezoidal rule. Toxicokinetic parameters, such as the terminal elimination half-life, apparent oral clearance, and apparent volume of distribution ($V_d/F$) were calculated. The maximum PQ concentration ($C_{max}$) and the time to reach maximum PQ concentration ($T_{max}$) were also obtained. Plasma PQ concentrations in nine patients were well described by a bi-exponential curve with a mean terminal elimination half-life of $13.1{\pm}6.8h$. $C_{max}$ and $AUC_{inf}$ were $20.8{\pm}25.7mg/l$ and $172.5{\pm}160.3h{\cdot}mg/l$, respectively. Apparent volume of distribution and apparent oral clearance were $50.9{\pm}61.3l/kg$ and $173.4{\pm}111.2l/h$, respectively. There were a significant correlation (r=0.84; p<0.05) between the PQ amount ingested and $C_{max}$. $AUC_{inf}$ also showed a significant correlation (r=0.83; p<0.05) with the PQ amount ingested. These correlations provide evidence that PQ has dose-linear toxicokinetic characteristics.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권1호
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• pp.47-51
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• 2005

The bioelectrochemical reduction of nitrate in the presence of various mediators including methyl viologen and azure A was studied using a 3-electrode voltammetric system. The catalytic potential for the reduction of the mediators was observed in the reactor, which for methyl viologen and azure A were -0.74 V and -0.32 V, respectively, with respect to the potential of Ag/AgCl reference electrode. This potential was then applied to a working electrode to reduce each mediator for enzymatic nitrate reduction. Nitrite, the product of the reaction, was measured to observe the enzymatic nitrate reduction in the reaction media. Methyl viologen was observed as the most efficient mediator among those tested, while azure A showed the highest electron efficiency at the intrinsic reduction potential when the mediated enzyme reactions were carried out with the freely solubilized mediator. The electron transfer of azure A with respect to time was due to the adhesion of azure A to the hydrophilic surface during the reduction. In addition, the use of the adsorbed mediator on conductive activated carbon was proposed to inhibit the change in the electron transfer rate during the reaction by maintaining a constant mediator concentration and active surface area of the electrode. Azure A showed better than nitrite formation than methyl viologen when used with activated carbon.