• Journal of Fisheries and Marine Sciences Education
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• v.25 no.5
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• pp.1079-1087
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• 2013

The pharmacokinetics of florfenicol (FF) after oral administration was studied in the cultured olive flounder, Paralichthys olivaceus, using high performance liquid chromatography (HPLC). After single administration of FF (20 mg/kg body weight) by oral route in olive flounder ($700{\pm}50$ g, $23{\pm}1.5^{\circ}C$), the concentration in the serum was determined at 1, 5, 10, 15, 24, 30, 50 and 168 h post-dose. The kinetic profile of absorption, distribution and elimination of FF in serum were analyzed fitting to a two-compartment model by WinNonlin program. The area under the concentration-time curve (AUC), maximum concentration ($C_{max}$), time for maximum concentration ($T_{max}$) and elimination time were 22.51 ${\mu}g{\cdot}h/mL$, 0.84 ${\mu}g/mL$, 8.62 h and 447 h, respectively. The results of this study related to dosage and withdrawal times could be used for prescription of FF in field for the treatment of bacterial diseases in olive flounder.

• Microbiology and Biotechnology Letters
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• v.33 no.3
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• pp.215-221
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• 2005

It was characterized the hexane biodegradation and mineralization using a hexane-degrading consortium, and analyzed its bacterial community structure by 16S rDNA PCR-DGGE (denaturing gradient gel electrophoresis). The specific growth rate (${\mu}_{max}$) of the hexane-degrading consortium was 0.2 $h^{-1}$ in mineral salt medium supplemented with hexane as a sole carbon source. The maximum degradation rate ($V_{max}$) and saturation constant ($K_{s}$) of hexane of the consortium are 460 ${\mu}mol{\cdot}g-DCW^{-1}{\cdot}h^{-1}$ and 25.87 mM, respectively. In addition, this consortium could mineralize $49.1{\%}$ of $^{14}C$-hexane to $^{14}CO_2$, and $43.6{\%}$ of $^{14}C$-hexane) was used for the growth of biomass. The clones isolated from the DGGE bands were closely related to the bacteria which were capable of degrading pollutants such as oil, biphenyl, PCE, and waste gases. The hexane-degrading consortium obtained in this study can be applied for the biological treatment of hexane.

• Journal of Pharmaceutical Investigation
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• v.18 no.3
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• pp.139-144
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• 1988

Piperacillin phthalidyl ester was synthesized by reacting piperacillin with triethylamine and bromophthalide in acetone and its chemical structure was determined by UV, IR, and PMR. The partition coefficient of the ester was increased and the ester was more lipophilic and less water soluble than piperacillin. The ester did not show the antimicrobial activity against Bacillus subtilis ATCC 6633 in vitro, but when hydrolyzed, the parent drug of ester, piperacillin, revealed antimicrobial activity in vivo. After a single oral dose of both piperacillin and the ester to rabbits, the serum piperacillin concentration was measured by bioassay. The ester exhibited improved pharmatokinetic characteristics: $T_{max}\;of\;2hr,\;C_{max}\;of\;4.26{\mu}g{\cdot}ml^{-1},K_{el}\;of\;0.057hr^{-1},\;and\;total\;AUC\;of\;85.42{\mu}g{\cdot}hr{\cdot}ml^{-1}$. Piperacillin on the other hand, did not exhibit any gastro-intestinal absorption.

• Korean Chemical Engineering Research
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• v.55 no.1
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• pp.40-47
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• 2017

Dust explosion hazards are always present when combustible dusts are manufactured or handled in the process. However, industries is experiencing difficulty in establishing chemical accident prevention measures because of insufficiency of information on dust explosion characteristics of combustible dust handled in industry. In this study, we investigated experimentally dust explosion characteristics of two kinds of multi-walled carbon nano tubes (MWCNT) different in particle size distribution and examined classification of dust explosion hazardous area for MWCNT manufacturing or handling process by applying the NFPA 499 code. As a result, $P_{max}$, $K_{st}$, LEL, MIE and MIT of MWCNT 1 having $124.2{\mu}m$ median diameter are obtained 6.3 bar, $56bar{\cdot}m/s$, $125g/m^3$, over 1000 mJ, and over $650^{\circ}C$. $P_{max}$, $K_{st}$, LEL, MIE and MIT of MWCNT 2 having $293.5{\mu}m$ median diameter are 6.2 bar, $42bar{\cdot}m/s$, $100g/m^3$, over 1000 mJ, and over $650^{\circ}C$, respectively. MWCNT 1, 2 are not categorized as combustible dust listed in the NFPA 499 Code for classification of dust explosion hazardous area because explosion severity and ignition sensitivity of MWCNT 1, 2 are below 0.35 and 0.01, respectively.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.647-651
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• 2004

In this study, some of bacterial growth kinetic parameters were delineated and evaluated for the biological nutrient removal processes such as the $A^2/O$, 4stage-BNR, Intermittent Cycle Extended Aeration System(ICEAS) and Intermittently Aerated Cylindrical Oxidation Ditch(IACOD) processes. $Y_H$ values for the ICEAS process ranged from 0.71 to 0.74, and were higher than those for the other processes. It seems to indicated that organic carbons uptaked by microorganism were more used up for cell synthesis rather than for energy components in the ICEAS process. $b_H$ for the ICEAS and IACOD processes were lower than those for $A^2/O$ and 4stage-BNR processes. The $\mu_{max{\cdot}A}$ for the ICEAS was higher than those for the other processes, which indicated that desirable operating conditions for nitrifying bacteria's growth were established.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.1
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• pp.57-64
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• 2004

Effects of light and temperature on the nitrate uptake and germling growth of Enteromorpha compressa (L.) Greville (Chlorophyta) were studied based on samples from Cheongsapo near Busan, Korea. In addition, their effects on fatty acids composition in thallus were examined. Nitrate uptake showed saturation kinetics. $V_{max}$ (maximal uptake rate) and its $K_s$ (half-saturation constant) at $20^{\circ}C,\;80\;{\mu}mol\;m^{-2}s^{-1},$ white light were $1.571\;{\mu}mol{\cdot}g\;fr\;wt^{-1}{\cdot}h^{-1}$ and 3.56 ${\mu}M$, respectively. In nitrate uptake with irradiance, wavelength and temperature, its rate represented respectively the highest value as $1.405\pm0.020,\;0.623\pm0.040,\;1.422\pm0.022\;{\mu}mol{\cdot}g\;fr\;wt^{-1}{\cdot}h^{-1}\;at\;100\;{\mu}mol\;m^{-2}s^{-1},$ red light, $20^{\circ}C$ and exhibited significant difference among the examined conditions (p<0.001). Germling growth of E. compressa also showed saturation kinetics, and $V_{max}$ and its $K_s$ value at $20^{\circ}C,\;100\;{\mu}mol\;m^{-2}s^{-1},$ 12:12 h were $56.18\%\;day^{-1}$ and 0.33 ${\mu}M$, respectively. SGR (specific growth rate) recorded a maximal value as 49.33-54.80, 39.07-50.72, $47.20-54.53\%\;dat^{-1}$ at $120\;{\mu}mol\;m^{-2}s^{-1},$ blue light and $18^{\circ}C$ respectively, and showed significant difference (p<0.001). Red light made the effective nitrate uptake, but germling growth was largely limited by the light. In fatty acids analysis, PUFAs (polyunsaturated fatty acids) were high at blue light, $18^{\circ}C,\;100\;{\mu}M\;NO_3^-.$ However, irradiance did not affect the production of PUFAs. In conclusion, nitrate uptake and germling growth of E. compressa showed saturation kinetics to external nitrate concentration, and were significantly affected by irradiance, wave length and temperature. Fatty acid composition was also influenced by the factors except for irradiance. Their maximal values, together with the highest production of PUFAs, were found at blue light band, $20^{\circ}C,\;100\;{\mu}mol\;m^{-2}s^{-1},\;and\;100\;{\mu}M\;NO_3^-.$

• Korean Journal of Clinical Pharmacy
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• v.12 no.2
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• pp.71-75
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• 2002

This study was carried out to compare the bioavailability of $Ceclex^{(R)}$ (test drug, cefaclor 250 mg/capsule) with that of $Ceclor^{(R)}$ (reference drug) and to estimate the pharmacokinetic parameters of cefaclor in healthy Korean adult. The bioavailability was examined on 20 healthy volunteers who received a single dose (250 mg) of each drug in the fasting state in a randomized balanced 2-way crossover design. After dosing, blood samples were collected for a period of 6hours. Plasma concentrations of cefaclor were determined using HPLC with UV detection. The pharmacokinetic parameters $(AUC_{0-6hr},\;C_{max},\;T_{max},\;AUC_{int},\;K_e,\;t_{1/2},\;Vd)$ F, and CL/F) were calculated with non-compartmental pharmacokinetic analysis. The ANOVA test was utilized for the statistical analysis of the $T_{max},\;log-transformed\;AUC_{0-6hr}\;log-transformed\;C_{max},\;t_{l/2},\;V_d/F$, and CL/F. The ratios of geometric means of AUC0-6hr and $C_{max}$ between test drug and reference drug were $103.2\%\;(6.74\;{\mu}g{\cdot}hr/ml\;vs\;6.53{\pm}g{\cdot}hr/ml)\;and\;100.4\%\;(4.85\;{\mu}g\ml\;vs\;4.82\;{\mu}g/ml)$, respectively. The $T_{max}$ of test drug and reference drug were $0.9\pm0.38\;hr\;and\;0.83\pm0.34$ hrs, respectively. The $90\%$ confidence intervals of mean difference of logarithmic transformed $AUC_{0-6h},\;and\;C_{max}$ were log $0.98{\sim}log$ 1.08 and log $0.88{\sim}log1.15$, respectively. It shows that the bioavailability of test drug is equivalent with that of reference drug. The estimated half-life of this study was longer $(1.21\pm0.27\;hrs\;vs\;0.5-1\;hr)$, the Vd/F was larger $(68.89\pm25.72L$ vs 24.9L), and the CL/F was higher $(38.62\pm7.09\;L/hr$ vs 24.9 L/hr) than the previously reported values.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.815-822
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• 1995

The toxicokinetics of rifapentine was studied after an oral administration to beagle dogs. High-performance liquid chromatography(HPLC) using column-switching technique was performed to determine the serum concentrations of rifapentine. The pharmacokinetic profiles of rifapentine were analysed using one-compartment open model. Following a single oral administration of 10mg/kg, pharmacokinetic parameters were determined as follows: maximum serum concentration($C_{max}$), $28.90{\mu}g/ml$; maximum concentration time($T_{max}$), 3.7hr; elimination half-life($t_{1/2}$, 4.7hr; area under the curve(AUC), $339.0{\mu}g{\cdot}hr/ml$; volume of disiribution/bioavailability (Vd/F), 0.21 l/kg; lag time, 24min; absorption rate constant($k_a$), $0.445hr^{-1}$; elimination rate constant($k_{el}$), $0.148hr^{-1}$. After 6 month multiple oral doses of 10mg/kg/day, parameters were as follows: $C_{max}$, $34.40{\mu}g/ml$; $T_{max}$, 2.6hr; $t_{1/2}$, 6.7hr; AUC, $391.3{\mu}g{\cdot}hr/ml$; Vd/F, 0.291/kg; $k_a$, $0.976hr^{-1}$; $k_{el}$, $0.104hr^{-1}$. The consistant kinetic parameters after a single and multiple oral administration show that there was no accumulation of rifapentine after 6 month oral administration. We also simulated the concentration of rifapentine after oral multiple administration of 10 and 50mg/kg/ day, based on the parameters obtained form the single administration. The measured serum concentrations of rifapentine were well fitted to the simulated results. The simulated results show that rifapentine readily reaches to steady-state after about 3 doses and the steady-state serum concentrations($C_{ss}$) are fluctuated in between $2.2{\sim}25.2{\mu}g/ml$, and $10.6{\sim}125.2{\mu}g/ml$ at the doses of 10 and 50mg/kg/day, respectively.

• YAKHAK HOEJI
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• v.40 no.4
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• pp.400-410
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• 1996

In oder to develop the controlled release of drugs from the suppositories, in vitro drug release and in vivo absorption in rabbits were investigated. Various suppo sitory forms with hollow cavities, into which drugs in the form of fine powder or solid dispersion system(SDS) could be placed, were utilized. The oleaginous Witepsol H-15 (WH-15) as a base, and indomethacin (IDM) of a very slightly soluble drug and propranolol-HCL (PPH) of a very soluble drug were employed as model drugs. The in vitro drug release showed that the cumulative release amount of PPH from PPH-(methylcellulose) MC-SDS and PPH-(ethylcellulose) EC-SDS hollow type suppositories reached 40% and 12% in 6 hrs,respectively. On the other hand, the drug release for a conventional suppository was 80% in 6 hrs. For the IDM suppositories,the cumulative drug release from IDM-(polyvinylpyrrolidone) PVP-SDS hollow type suppositories reached 99% in 24 hrs, whereas that from a conventional suppository reached 85%. An in vivo experiment with rabbits showed that IDM-PVP-SDS hollow type suppository delayed the absorption of IDM, significantly. The $t_{max},\;C_{max}\;and\;AUC_{0{\to}8}$ of IDM-PVP-SDS suppository were 60 min, 12.12${\mu}g$/ml and 2657${\mu}g$/ml/min, respectively. The $t_{max},\;C_{max}\;and\;AUC_{0{\to}8}$ of controlled group were 20 min, 15.49${\mu}g$/ml and 2190${\mu}g$/ml/min, respectively.

• Fisheries and Aquatic Sciences
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• v.5 no.3
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• pp.200-205
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• 2002

Temperature-dependent pharmacokinetics of ciprofloxacin (CIP) was studied in the cultured olive flounders, Paralichthys olivaceus, and black rockfish, Sebastes schlegeli using high performance liquid chromatography (HPLC) originally developed for quinolone determination from livestock. Pharmacokinetics of CIP was apparently affected by ambient water temperature. In a two-compartment model for flounders after oral dosage of 20 mg/kg, $K_{01},\;at\;13^{\circ}C$ and $23^{\circ}C$ were 4.18 and 1.20/hr, respectively. The $K_{10},\;T_{max}\;and\;C_{max}\;at\;13^{\circ}C$ were 5.574/hr, l4.37${\mu}g/mL\;and\;3.15{\mu}g/mL,$ respectively. The corresponding values at $23^{\circ}C$ were l2.84/hr, 15.39${\mu}g/mL\;and\;6.38{\mu}g/mL$, respectively. The AUC, $T_{1/2} (\alpha)\;and\;T_{1/2}\;(\beta)$ were 278.23 ${\mu}g \cdot hr/mL$, 0.24hr and 47.02hr at $13^{\circ}C$ and 3l7.8l${\mu}g \cdot hr/mL$, 0.30 hrs and 60.78hrs at $23^{\circ}C$ for the flounder, respectively. Similar CIP pharmacokinetics were revealed in the black rockfish after oral dosage of 20 mg/kg under the two water temperature regimes. These pharmacokinetical results have some implication in the optimal usage of recently introduced antibacterials in the farmed fish, which were primarily adapted for poultry and mammalian species.