• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.988-992
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• 2008

A poly(methyl red) film-modified glassy carbon electrode (PMRE) was fabricated for determination of norfloxacin (NFX). The electrochemical behavior of NFX was investigated and a well-defined oxidation peak with high sensitivity was observed at the film electrode. PMRE greatly enhanced the oxidation peak current of NFX owing to the extraordinary properties of poly(methyl red) film. Based on this, a sensitive and simple voltammetric method was developed for measurement of NFX. A sensitive linear voltammetric response for NFX was obtained in the concentration range of $1\;{\times}\;10^{-6}\;-\;1\;{\times}\;10^{-4}$ mol/L and the detection limit was $1\;{\times}\;10^{-7}$ mol/L using linear sweep voltammetry (LSV). The proposed method possessed advantages such as low detection limit, fast response, low cost and simplicity. The practical application of this new analytical method was demonstrated with NFX pharmaceuticals.

• 대한수의학회지
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• 제37권1호
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• pp.147-154
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• 1997

국내에서 많이 사용되고 있는 제2세대 quinolone 항생제인 norfloxacin(NFX)에 대한 약역학적인 특성을 구명하기 위하여 국내에서 분리된 동물유래 병원성 세균에 대하여 시험관내에서 실험을 수행하여 다음과 같은 결과를 얻었다. 즉, E coli(n=89) 대한 NFX의 $MIC_{50}$와 $MIC_{90}$는 공히 0.02g/ml이었으며, Streptococcus spp.(n=36)에 대한 NFX의 $MIC_{50}$는 2g/ml 그리고 $MIC_{90}$는 4g/ml로 나타났다. Salmonella spp.(n=56)에 대한 NFX의 $MIC_{50}$와 $MIC_{90}$ 모두 0.2g/ml로 강한 항균력을 보였으며, Streptococcus spp.(n=24)에 대한 NFX의 $MIC_{50}$는 2g/ml 그리고 $MIC_{90}$가 4g/ml로 나타났다. Bacillus spp.(n=34)는 NFX의 $MIC_{50}$와 $MIC_{90}$는 모두 0.4g/ml으로서 대부분의 병원성 세균에 대해서 $MIC_{50}$와 $MIC_{90}$치가 동일하든지 또는 매우 비슷한 수치를 보여주었다. 그러나 NFX는 혐기성세균인 Clostridium spp.(n=34)에 대해서는 항균력이 매우 낮았다. 현재 수의임상에서 항균제 병용요법이 많이 응용되고 있는 것을 고려하여 NFX와 다른 항생물질간의 분획억제농도 (FICs)를 E coli 88ac을 시험균주로 하여 실험한 결과, NFX와 colistin과 병용할 때 FIC 값이 0.38로서 상승작용을 그리고 gentamicin, trimethoprim, amikacin, penicillin 및 tylosin과의 병용시 FIC 값이 각각 0.52, 0.56, 0.63, 1.00 및 1.02로서 상가작용을 보여주었으며, tetracyclin과의 병용시의 FIC값은 1.49로서 길항작용을 나타냄을 알 수 있었다. 한편 실제 항균제의 임상적용시 매우 주요한 요소인 항균활성후 저농도유효성(PAE)을 알아보기 위하여 E coli AB1157을 시험균주로 측정한 결과 PAE은 0.90~1.02 시간 그리고 S aureus R-209에 대해서는 PAE가 1.58~1.99 시간으로서 그람음성균 및 그람양성균 모두에 대해서 긴 PAE를 갖고 있음을 알 수 있었다.

• 대한수의학회지
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• 제44권2호
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• pp.201-206
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• 2004

Norfloxacin (NFX) is a fluorquinolone antibacterial agent with a high antimicrobial activity and might have great potential for treating common infections in poultry. The objective of this study was to obtain comparative pharmacokinetic data after a single oral administration and medication with drinking water of norfloxacin-glycine acetate (NFX-GA) at the dose rate of 10 mg/kg bw in broilers. Fifty minutes following oral administration of NFX-GA, serum concentrations peaked at $1.32{\mu}g/mL$ (range $1.03-1.45{\mu}g/mL$). Serum concentration of NFX declined with a half-life of $7.21{\pm}1.81$ h. On the third day after administration of medicated drinking water, steady-state was reached, with mean concentrations of NFX of $0.70{\pm}0.35{\mu}g/mL$. The concentration of NFX after medication of NFX-GA with drinking for 3 days provides sufficient levels to obtain maximum therapeutic effects and maintains the serum persistence of concentration exceeding MIC.

• 한국통신학회논문지
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• 제36권6C호
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• pp.343-348
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• 2011

이 논문은 NFxLMS (normalized filtered-x least mean square) 적응 필터기반의 실시간 ANC (active noise control) 무선 헤드셋에 관해서 연구한다. RMS (root mean square) 지연 분포를 측정한 후 채널을 보정해서 학습시간을 줄이고, 학습 시간동안 NFxLMS 필터 계수를 갱신해서 잡음 제거 필터의 수렴속도를 개선하는 방법을 제안한다. 제안한 방법을 실제 잡음 환경에서 이용할 경우에 짧은 학습 시간과 빠른 수렴속도를 가지면서 기존 잡음 제거기와 비슷한 성능을 가지는 잡음 제거기를 구성할 수 있다.

• 드라이브 ㆍ 컨트롤
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• 제9권1호
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• pp.44-51
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• 2012

• 폴리머
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• 제33권2호
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• pp.137-143
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• 2009

이 연구에서 norfloxacin(NFX)이 담지된 poly($\varepsilon$-caprolactone)/poly(ethylene glycol)(PCL/PEG, abbreviated as CE) 이중블록공중합체로 구성된 고분자 미셀을 제조하였다. 입자크기는 PCL블록길이에 따라 60$\sim$200 nm사이였다. 임계회합농도는 소수성 PCL 블록길이가 증가함에 따라 감소하는 경향을 보였다. $^1H$-NMR 연구에서 PCL 블록은 내핵, PEG는 외피를 형성한 미셀구조로 형성되었음을 확인하였다. 약물의 방출은 약 2일간 지속되었으며 PCL블록길이와 약물함량이 증가함에 따라 감소하는 경향을 보였다. 항미생물 성능 실험에서 고분자 미셀은 기존의 NFX와 비슷한 독성을 보였다.

• 한국어병학회지
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• 제15권2호
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• pp.49-56
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• 2002

Effects of Temperature on the Pharmacokinetics of norfloxecin (NFX) were studied in the cultured carp,Cyprinus carpio, and cel, Anguilla japonica, using high performance liquid chromatography (HPLC) originally developed for quinolone determination in livesrocks. Pharmacokinetics of NFX was apparently affected by ambiem water temperature. In a two-compaament model for carp after oral dosage of 20 mg/K01 at $13^{\circ}C$ and $23^{\circ}C$ and 5.20/hr, respectively. In carp the $K_{\iota\nu}$, $T_{max}$and $C_{max}$ for carp at $13^{\circ}C$ were 13.30/hr, 17.44 ${\mu}g$/$m\ell$ and 7.00 ${\mu}g$/$m\ell$, respectively. The" correspoeding values at $23^{\circ}C$ were 3.93/hr, 15.40 ${\mu}g$/$m\ell$ and 9.44 ${\mu}g$/$m\ell$, respectively. The AUC and T were 355.66 ${\mu}g$ hr/$m\ell$, and 12.70 hr at $13^{\circ}C$ and 417,24 ${\mu}g$ hr/$m\ell$ and 13.86 hrs at $23^{\circ}C$, respectively. Similar trends were revealed in the NFX pharmacokinetics of eel kept under the two water temperature regimes aftee oral NFX dosage of 20 mg/kg. These pharmacokinetkal results have some implication in the optimal usage of recently introduced antibacterials in farmed fish, which were originally adapted for poultry and mammalian species.

• 폴리머
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• 제26권4호
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• pp.535-542
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• 2002

투석법을 이ctide-co-glycolide) (PLGA) 나노입자를 제조하고 다양한 용매에 따른 입자 크기, 약물 함유량, 생분해도 등과 같은 물리ㆍ화학적 특성을 조사하였다. Dimethylacetamide (DMAc), dimethylformamide (DMF), dimethylsulfoxide (DMSO)로 제조된 PLGA 나노입자의 크기는 acetone으로 제조한 입자보다 적었다. 또한, 약물 함유량은 DMAc>DMF>DMSO=acetone 순서였다. PLGA 나노입자는 scanning electron microscopy (SEM)과 transmission electron microscopy (TEM)의 측정으로 구형임을 알 수 있었다. 계면활성제를 사용하지 않는 나노입자에 봉입된 norfloxacin (NFx)은 X-ray diffraction 분석을 통하여 입자 표면에 약물을 가지지 않는 좋은 약물 봉입 효율을 가짐을 알 수 있었다. 모델약물로 사용된 NFx의 방출속도는 약물 함유량뿐만 아니라 입사크기에 의해 좌우된다. 또한 PLGA 나노입자의 분해속도는 아세톤보다는 DMF를 사용하였을 때 더 빠르며 이는 PLGA 나노입자의 생분해성도 입자크기에 좌우된다는 것을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제19권9호
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• pp.962-967
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• 1998

Block copolymers consisting of poly(rbenzyl L-glutamate) (PBLG) as the hydrophobic part and poly(ethylene oxide) (PEO) as the hydrophilic part were synthesized and characterized. Polymeric micelles of the block copolymers (abbreviated GEG) were prepared by a dialysis method. The GEG block copolymers were associated in water to form polymeric micelles, and the critical micelle concentration (CMC) values of the block copolymers decreased with increasing PBLG chain length in the block copolymers. Transmission electron microscopy (TEM) observations revealed polymeric micelles of spherical shapes. From dynamic light scattering (DLS) study, sizes of polymeric micelles of GEG-1, GEG-2, and GEG-3 copolymer were 106.5±59.2 nm, 79.4±46.0 nm, and 37.9±13.3 nm, respectively. The drug loading contents of GEG-1, GEG-2 and GEG-3 polymeric micelles were 12.6, 11.9, and 11.0 wt %, respectively. These results indicated that the drugloading contents were dependent on PBLG chain length in the copolymer; the longer the PBLG chain length, the more the drug-loading contents. Release of norfloxacin (NFX) from the nanoparticles was slower in higher loading contents of NFX than in lower loading contents due to the hydrophobic interaction between PBLG core and NFX.

• 한국동물위생학회지
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• 제29권2호
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• pp.111-122
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• 2006

A direct, accurate and sensitive chromatographic analytical method for quantitative determination of four fluoroquinolones (norfloxacin, cirprofloxacin, danofloxacin and enrofloxacin) in chicken, pork and beef edible muscle is proposed in the present study. The developed method was successfully applied to the determination of enrofloxacin, as the main component of commercially available veterinary drugs. The samples were homogenized and the antimicrobials were added, then they were extracted twice with dichloromethane. Fluoroquinolone antibiotics were separated on an agilent $250x4mm,\;C_{18},\;5{\mu}m$, analytical column, at $25^{\circ}C$. The mobile phase consisted of a mixture of DW : acetonitrile : triethylamine(80:19:1%, v/v, pH 3.0) leading to retention times less than 14 min. at a flow rate 0.5 ml/min. These fluoroquinolones were detected by liquid chromatography with fluorescence at 290 nm excitation and 465 nm emission. The limits of quantification in each edible muscle (chicken, pork, and beef) were 0.32-6.54 ng/g. Using 0.5 g of each sample, average recovery rates at fortification levels of 0.05, 0.1 and 0.2 ${\mu}g/ml$ ranged 70.14-71.71% for NFX, 71.87-73.89% for CFX, 82.16-92.35% for DFX, and 90.13-98.12 for EFX This is a simple and economic method to quantify the presence of NFX, CFX, EFX and DFX in edible muscle of animal origin.