• 제목/요약/키워드: Half Life ($t_{1/2}$)

검색결과 250건 처리시간 0.027초

세팔로스포린 3'-퀴놀론의 물리화학적 성질, 안정성 및 체내약물동태 (Physicochemical Properties, Stabilities and Pharmacokinetics of Cephalosporin 3'-Quinolone Dithiocarbamate)

  • 나성범;공재양;김완주;지웅길
    • 약학회지
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    • 제37권6호
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    • pp.638-646
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    • 1993
  • A cepfialosporin with an aminothiazoiylmethoxyimino-type side chain at the 7 position and bicyclic quinolone dithicarbamate at the 3' position was synthesized. It has broad and potent antivacterial activity in vitro. The antibacterial spectrum reflects contributions of both the cephalosporin moiety and the quinolone moiety. Thus, this compound was named DACD implying a dualaction cephalosporin derivative. In this paper, the physicochemical proper-ties (lipid-water partition, pKa), stability and pharmacokinetics of DACD were determined and compared with cefotaxime 3'-norfloxacin dithiocarbamate (CENO). Stability tests were studied in pH 1.20, 6.80 and 8.00 buffers and in the presence of AB type human plasma, rat liver homogenate and its .betha.-lactamase. The pharmacokinetic parameters of DACD were evaluated in mice after a single intravenous dose of 40 mg/kg. The results are as follows. The lipid-water partition coefficient of DACD was higher than that of CENO. The calculated pKa values of CENO and DACD, were 6.82$\pm$0.03, 7.53$\pm$0.21, respectively. In the hydrolysis test, half-lives (t$^{1/2}$) of CENO and DACD was 66.0 hr and 80.0 hr in pH 6.80 buffer, 190 hr and 91.4 hr in pH 8.00 buffer. CENO and DACD were rapidly hydrolyzed in human plasma and in rat liver hornogenate. Half-lives (t$_{1/2}$ of CENO and DACD were 1.29 hr and 1.15 hr in hyman plasma, 0.62 hr and 0.71 hr rat liver homogenate. In $\beta$-lactamase stability test, CENO and DACD were very stable to the .betha.-lactamases obtained from three different strains. Half-life (t$_{1/2}$) and areas under the curve (AUC) in mice were 2.33 hr and 15.97 (mg.h/1), respectively.

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한국인 환자에서의 아미카신의 체내약물동태학적 파라메타에 관한 연구 (Studies on Pharmacokinetic Parameters of Amikacin in Korean Patients)

  • 용재익;김옥남;문민정;신완균
    • Journal of Pharmaceutical Investigation
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    • 제20권1호
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    • pp.19-28
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    • 1990
  • Pharmacokinetic parameters of aminoglycosides are dependent on renal function, sex, age, hematocrit, fever, lean body weight (LBW) and disease states, etc. Therefore, the individual pharmacokinetic parameters such as half life $(t^{1/2})$ and volume of distribution(Vd) are needed to achieve optimal therapy. However these parameters had not been determined in Koreans. The purpose of this study was to evaluate the Vd and $t^{1/2}$ of amikacin in Korean patients who had normal renal function, to compare the mean values of study group with that reported in the literature and to compare the measured $t^{1/2}$ with the expected $t^{1/2}$ based on actual body weight (ABW), LBW and ideal body weight (IBW), respectively. Based on data, the Vd was greater than the literature and $t^{1/2}$ was similar to the literature. The predicted $t^{1/2}$ based on IBW was the closest to actual $t^{1/2}$. And postpartum patients had greater Vd than other group and had lower correlation between actual elimination rate constant and calculated creatinine clearance but higher correlation between actual elimination rate constant and Vd than other group.

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돼지에서 근육주사한 Abamectin에 대한 HPTLC 분석 및 약물동태학 (Quantitation of abamectin by HPTLC and its pharmacokinetics after intramuscular injection in pigs)

  • 박승춘;윤효인
    • 대한수의학회지
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    • 제40권1호
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    • pp.35-41
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    • 2000
  • We established a new method to analyze abamectin using HPTLC (high performance thin layer chromatography) in order to obtain its pharmacokinetic profiles in pigs. Recovery of abamectin in pig serum after fluorescence derivatization was $80.01{\pm}3.82%$ at 0.1ppm and $83.67{\pm}3.63%$ at 10ppm, respectively. Detection reproducibility in terms of coefficient variation (c.v.) was 3.09% and 2.74% (intra-day), and 3.71% and 51.7%(inter-day), for 0.1 and 10ppm, respectively. Pharmacokinetics of abamectin was studied in five Yorkshire-Landrace mixed bred male pigs ($35.0{\pm}2.7kg$) administered intramuscularly 0.3mg/kg b.w. Pharmacokinetic profiles of abamectin in pigs were described by the 1-compartment open model with first-order absorption and first-order elimination. AUC (area under the curve) was $262.65{\pm}16.44ng{\cdot}day/ml$ and the biological elimination half-life ($t_{1/2},\;k_e$) was $5.28{\pm}0.84$ days, indicating somewhat high bioavailability and long half-life by the intramuscular route. We suggest intramucular injection of abamectin could be also used in place of the recommended route of its subcutaneous administration so far.

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I-131 치료를 받은 분화갑상선암 환자에서 I-131의 유효반감기 (Effective Half-life of I-131 in Patients with Differentiated Thyroid Cancer Treated by Radioactive I-131)

  • 박석건
    • Nuclear Medicine and Molecular Imaging
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    • 제42권6호
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    • pp.464-468
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    • 2008
  • 목적 : I-131 치료를 받는 분화갑상선압 환자에서 I-131의 유효반감기($T_{eff}$)는 투여량의 계산이나 격리치료의 기간을 결정하기 위해서는 알아야 할 값 중 하나이다. 그러나 $T_{eff}$를 계산하려면 자주 선량을 측정해야 하기 때문에 측정하는 사람의 방사선노출이 문제가 된다. 이런 이유로 아직 한국인에서 $T_{eff}$값은 찾기 어렵다. 측정하는 사람에 대한 방사선 노출 없이 연속적으로 선량 변화를 측정하고, 이로부터 $T_{eff}$와 48시간 체내잔류량, 1.1 GBq이하가 될 때까지의 시간을 계산하고자 하였다. 방법: 방사선 선량계의 탐침은 격리치료실 안의 벽에 고정하고, 선량계는 밖에서 읽도록 하는 간단한 방법을 사용하였다. 2006년 1월부터 12월까지 I-131 치료($3.7{\sim}7.4\;GBq$)를 받은 분화갑상선 환자 68명(여=55, 남=13, 연령=$47{\pm}13.7$)에서 격리치료실 입원 중 선량변화를 측정하였다. 이 값을 가지고 개인용 컴퓨터의 스프레드시트 프로그램을 사용하여 $T_{eff}$를 계산하였다. 모든 환자에서 혈중 크레아티닌 농도를 측정하였다. 결과: $T_{eff}$$15.4{\pm}4.3$ ($9.4{\sim}32.5$)시간이었다. $T_{eff}$는 혈중 크레아티닌이 증가할수록 길어지는 경향은 있었으나, 상관계수는 높지 않았다(r=0.45). 48시간 후 남은 양은 $4.9{\pm}4.2$ ($1{\sim}23$)%였다. 전신에 남은 양이 1.1GBq 이하가 될 때까지의 시간은, 9.25GBq를 투여한다고 가정했을 때에는 $47.1{\pm}13.2$시간, 7.4 GBq일 때 $42.1{\pm}11.9$시간, 5.55 GBq일 때 $35.7{\pm}10$시간, 3.7 GBq일 때 $26.7{\pm}7.5$시간으로 계산되었다. 결론: 선량계의 탐침과 몸체를 분리하는 간단한 방법으로 측정하는 사람의 방사선노출이 없이 격리치료실에 입원한 환자의 선량변화를 연속적으로 측정할 수 있었고, 유도된 곡선으로부터 $T_{eff}$를 계산했다. 이 값을 이용하여 48시간 체내잔류량과 투여한 양이 1.1 GBq 이하가 될 때까지의 시간을 계산하였다.

여자 중.고등학생의 의복생활 실태에 관한 조사연구 -봄.여름 의복을 중심으로- (A Study on the Actual State of High School Girls' Clothing in Everyday Life -Especially on Spring and Summer Wear-)

  • 남상우
    • 대한가정학회지
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    • 제26권2호
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    • pp.39-47
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    • 1988
  • The aim of this study is to grasp the actual state of high school girls' clothing after liberalization of their uniform and to provide the reasonable guidance materials in clothing for both schools and homes. These are the results of the study 1. In the aspect of the favor of clothing and the interest in about clothes. a. They were fond of wearing "T" shirts, blue jeans in summer and pants and jackets in spring as their school wear. That implies that they enjoy wearing active and practical clothes. b. In the aspect of color, majority of them favored blue or similar colors, Also they had the tendency to love soft, simple clothe and more students preferred cloth without pattern. c. In their choice of them, they seldom paid attention to the informative-label are not their chief interest. d. More than half of girls prepare one or two suits in advance in a season, and they would prepare them deliberately This implies that their everyday life inclothing is based on the economic motive. 2. In the aspect of the purchasing clothes, a. Most of the girls bought them at the market and some of them at the direct-sales stall. b. when they purchased clothes, most girls were accompanied by their/mother and senior girls more often by their friends. c. The price and kinds of their favorite clothes such as "T" shirts and blouse was 5,000 won or so, and skirts, pants, one-piece and jackets are from the range of 5,000 won to below 10,000 won mostly. d. In regard to so-called brand-name items by popular designers, half of the girls responded that they wear some of such kinds of items because of superiority of sewing and longterm wearing, and the other half tend not to wear them due to high price.

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그레이브스 갑상선기능항진증 환자의 방사성옥소($^{131}I$) 치료시 실제 유효반감기의 측정 (Measurements of Actual Effective Half-Life in $^{131}I$ Therapy for Graves' Hyperthyroidism)

  • 소용선;김명선;권기현;김석환;김태형;한상웅;김은실;김종순
    • 대한핵의학회지
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    • 제30권1호
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    • pp.77-85
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    • 1996
  • 목적 : 그레이브스 갑상선기능항진증 환자에서 개개인마다 유효반감기가 차이가 있기 때문에, 방사성옥소 치료시 용량산출법에서, 고정된 유효반감기를 사용하는 경우에는 환자에 따라 과용량 뿐만아니라, 부족한 용량을 투여하게 되는 문제점이 있다. 저자들은 환자마다 다양하게 나타나는, 유효반감기를 $^{131}I$ 치료의 효과를 결정하는 가능한 한 인자로서 평가하고, 방사성옥소 투여후에 실제 유효반감기를 추정하고, 이를 기준으로 환자에게 실제 흡수된 방사선 흡수선량을 구하고 예정 흡수선량에 도달하기 위해 필요한 조사선량을 추정하기 위해서 본 연구를 시작했다. 대상 및 방법 : 대상은 1995년 4월부터 본원의 갑상선 클리닉을 방문한 환자중 그레이브스병 갑상선기능항진증으로 진단받았으나 항갑상선제를 장기간 복용에도 불구하고 관해를 유도하지 못했던 경우와, 항갑상선제에 대한 부작용으로 복용할 수 없는 환자 및 환자가 수술적 치료를 거부한 12명의 환자를 대상으로 방사성옥소 치료를 실시하였다. 수정된 Quimby-Marrinelli[투여량(MBq)=$absorbed\;dose(100Gy){\times}thyroid\;weight(g){\times}25{\div}T_{1/2}(day){\div}24hr$ $^{131}I$ uptake(%)]공식에 의해서 계산된 용량을 기준으로 방사성옥소를 투여한 후에 24, 48, 72, 96, 120시간당 방사성 옥소의 갑상선흡수율을 구한후 생물학적반감기, 유효반감기, 흡수선량을 구하였다. 결과: 1) 환자들에서 방사성옥소 투여시 실제 생물학적반감기는 9.5일에서 67.2일까지 다양하게 나타났고 평균 $21{\pm}13.0$(S.D.)일 이었다. 유효반감기는 평균 $5.3{\pm}0.88$(S.D.)일 이었으며 4.3일에서 7.1일까지였다. 2) 평균 방사성옥소 투여량은 532MBq(S.D.=${\pm}254$), 이때 실제 흡수선량은 112Gy(S.D.=${\pm}50.9$)였고, 갑상선조직 1그람당 100Gy의 흡수선량의 도달에 필요한량은 평균 583MBq(S.D.=${\pm}385$)였으며 평균 51MBq의 추가 용량투여가 필요하였다. 3) 방사성옥소의 추적자용량과 치료량에서의 갑상선 옥소섭취율의 변화는 t 값이 3.85, p<0.001로서 유의수준 0.01에서 유의한 차가 인정되었다. 4) 갑상선 중량측정에 있어서 갑상선스캔과 초음파사이에 유의한 차이를 보이지 않았다. 5) 유효반감기, 갑상선중량, 치료전과 치료후의 방사성옥소섭취율은, 40세 이전과 40세 이후의 양군에 있어서 유의한 차이를 보이지 않았다. 결론 : 그레이브스병 환자의 방사성옥소 치료시 용량결정 방법에서 실제 유효반감기를 이용한 방법은, 치료자가 목표로 한 흡수선량을 환자들에게 되도록 정확하게 투여하여, 방사성옥소 투여 후 잦은 빈도로 발생하는 갑상선기능저하증과, 치료실패의 빈도를 줄일 수 있을 것으로 생각한다.

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Potential Nitrogen Mineralization and Availability in Upland Soil Amended with Various Organic Materials

  • Im, Jong-Uk;Kim, Song-Yeob;Jeon, Seong-Hwa;Kim, Jang-Hwan;Yoon, Young-Eun;Kim, Sook-Jin;Lee, Yong-Bok
    • 한국토양비료학회지
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    • 제50권1호
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    • pp.40-48
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    • 2017
  • In this study, we evaluated the nitrogen (N) mineralization potential and Nitrogen use efficiency (NUE) of oil-cake, compost, hairy vetch and barley, which are the most widely used organic amendments in South Korea. The N mineralization potential (No) for organic fertilizers treated soil was highest for the hairy vetch treatment with a value of $18.9mg\;N\;100\;g^{-1}$, followed by oil-cake, barley and compost. The amount of pure N mineralization potentials in hairy vetch, oil-cake, barley and compost treatments were 8.42, 7.62, 3.82 and $3.60mg\;N\;100\;g^{-1}$, respectively. The half-life ($t_{1/2}$) of organic N in soil amended with oil-cake fertilizer mineralized quickly in 17 days. While, $t_{1/2}$ values of organic N for the compost and barley treatments accounted to 44.4 and 44.1 days, respectively. Oil-cake was good in supplying nutrients to plants. Compost and barley inhibited plant growth in the beginning growth stage and this is attributed to N immobilization effect. The results of this study highlight that compost and barley could be used as potential slow release fertilizers in conventional agriculture.

프로카인아미드의 HPLC 분석법 및 한국인에서의 약동학적 특성 (HPLC Determination and Pharmacokinetic Profile of Procainamidein Korean Subjects)

  • 배정우;김현경;양상인;김지홍;김경혜;장츤곤;박영서;손의동;이석영
    • 약학회지
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    • 제49권3호
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    • pp.193-197
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    • 2005
  • Procainamide is the drug of second choice (after lidocaine) in most coronary care units for the treatment of sustained ventricular arrhythmias associated with acute myocardial infarction. The purpose of this study was to develop the efficient assay method of procainamide in human plasma and to assess the pharmacokinetic profile of procainamide in healthy Korean volunteers. The pharmacokinetics of procainamide administered orally was evaluated after a dose of 250 mg. Procainamide in plasma was assayed using a specific HPLC method with UV absorbance at 275 nm. AUC was $4.58{\pm}0.90 {\mu}g/ml-hr$, $C_{max}\;1.34{\pm}0.39{\mu}g/ml$, $T_{max}\;1.06{\pm}0.34 hr$ and half-life $3.07\pm0.34 hr$. $T_{max}$ was slightly shorter than that in Caucasian (1-2 hr), whereas the half-life was similar to that in Caucasian (2.5-4.1 hr).

Circadian Changes in Pharmacokinetics of Sulfamethoxazole Administered Orally to Rabbits

  • Choi, Jun-Shik;Jung, Eun-Jung
    • Archives of Pharmacal Research
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    • 제24권4호
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    • pp.338-341
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    • 2001
  • Circadian variations of sulfamethoxazole pharmacokinetics were studied after a single oral administration of sulfamethoxazole, 50 mg/kg, to rabbits at 09:00 (a.m.) and 22 :00 (p.m.). The profiles of plasma sulfamethoxazole concentration showed from 6h to 24 h significant statistical difference (p<0.05) between 09:00 and 22:00. The half-life $t_{1/2} was significantly shorter in the morning (11.2 $\pm$3.2 h) when compared to the nighttime (15.4 $\pm$ 3.5h) (7< 0.05). The AUC was significantly decreased in the morning (1325 $\pm$ 264${u}g/ml$.h) than that in the nighttime (2059 $\pm$ 379${u}g/ml$. h) (p<0.05). Tota1 body clearance ($Cl_t$ was significantly higher when sulfamethoxazole was given in the morning (6.65 $\pm$ 0.23 ml/min) versus in the nighttime (4.28 $\pm$ 0.20 ml/min) (p<0.05).

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Pharmacokinetics of SD-0542, a Novel Histone Deacetylase Inhibitor, in Rats

  • Shin, Beom-Soo;Yoo, Sun-Dong
    • Journal of Pharmaceutical Investigation
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    • 제35권5호
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    • pp.349-353
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    • 2005
  • This study reports the pharmacokinetics of a novel histone deacetylase inhibitor, SD-0542, in rats after i..v. and oral administration. SD-0542 was injected intravenously at doses of 10, 20, and 40 mg/kg. The terminal elimination half-life $(t_{1/2})$, systemic clearance (Cl), and steady-state volume of distribution $(V_{ss})$ remained unaltered as a function of dose, with their values ranging from 2.0-2.5 hr, 157.2-214.1 ml/min/kg, and 11.1-17.5 L/kg, respectively, whereas, the initial serum concentration $(C_0)$ and AUC increased linearly as the dose was increased. Renal excretion of SD-0542 was minimal. Oral pharmacokinetic studies were conducted in rats at a dose of 20 mg/kg. The $T_{max}$, Cl/F, $V_{z}/F$, and $t_{1/2}$ were 2.0 hr, 92864 ml/min/kg, 16331 L/kg, and 2.0 hr, respectively. Taken together, SD-0542 showed linear pharmacokinetics over the i.v. bolus dose range studied. SD-0542 was poorly absorbed, with the absolute oral bioavailability of 0.9%.