• 제목/요약/키워드: pharmacokinetic

검색결과 927건 처리시간 0.037초

Prognostic Value of Dynamic Contrast-Enhanced MRI-Derived Pharmacokinetic Variables in Glioblastoma Patients: Analysis of Contrast-Enhancing Lesions and Non-Enhancing T2 High-Signal Intensity Lesions

  • Yeonah Kang;Eun Kyoung Hong;Jung Hyo Rhim;Roh-Eul Yoo;Koung Mi Kang;Tae Jin Yun;Ji-Hoon Kim;Chul-Ho Sohn;Sun-Won Park;Seung Hong Choi
    • Korean Journal of Radiology
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    • 제21권6호
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    • pp.707-716
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    • 2020
  • Objective: To evaluate pharmacokinetic variables from contrast-enhancing lesions (CELs) and non-enhancing T2 high signal intensity lesions (NE-T2HSILs) on dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging for predicting progression-free survival (PFS) in glioblastoma (GBM) patients. Materials and Methods: Sixty-four GBM patients who had undergone preoperative DCE MR imaging and received standard treatment were retrospectively included. We analyzed the pharmacokinetic variables of the volume transfer constant (Ktrans) and volume fraction of extravascular extracellular space within the CEL and NE-T2HSIL of the entire tumor. Univariate and multivariate Cox regression analyses were performed using preoperative clinical characteristics, pharmacokinetic variables of DCE MR imaging, and postoperative molecular biomarkers to predict PFS. Results: The increased mean Ktrans of the CEL, increased 95th percentile Ktrans of the CELs, and absence of methylated O6-methylguanine-DNA methyltransferase promoter were relevant adverse variables for PFS in the univariate analysis (p = 0.041, p = 0.032, and p = 0.083, respectively). The Kaplan-Meier survival curves demonstrated that PFS was significantly shorter in patients with a mean Ktrans of the CEL > 0.068 and 95th percentile Ktrans of the CEL > 0.223 (log-rank p = 0.038 and p = 0.041, respectively). However, only mean Ktrans of the CEL was significantly associated with PFS (p = 0.024; hazard ratio, 553.08; 95% confidence interval, 2.27-134756.74) in the multivariate Cox proportional hazard analysis. None of the pharmacokinetic variables from NE-T2HSILs were significantly related to PFS. Conclusion: Among the pharmacokinetic variables extracted from CELs and NE-T2HSILs on preoperative DCE MR imaging, the mean Ktrans of CELs exhibits potential as a useful imaging predictor of PFS in GBM patients.

Pharmacokinetic and Pharmacodynamic Modeling of a Proton Pump Inhibitor

  • Bae, Kyun-Seop;Jang, In-Jin
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.223-224
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    • 2002
  • Pharmacokinetic (PK) and pharmacodynamic (PD) study of a new reversible proton pump inhibitor (YH1885, Yuhan Pharmaceutical Co.) was done as a phase 1 clinical trial in Seoul national University Hospital Clinical trialcenter. Single dose of 60, 100, 150, 200, and 300mg were administered to total 20 healthy subjects under fasting state. Six subjects were given 100 mg after food and 12 subjects were given multiple doses of 150 and 300 mg every day for 7 days under fasting state. (omitted)

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Mechanistic Pharmacokinetic/pharmacodynamic Modeling in Isolated Perfused Organs and at the Whole-Body Level

  • Weiss, Michael
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.218-219
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    • 2002
  • In the past, the development of pharmacokinetic/pharmacodynamic (PK/PD) models for quantitating the time course of drug responses was mainly based on two types of models, the empirical effect compartment model that simply accounts for the delay between effect and plasma concentration (hysteresis) and the mechanism-based so-called indirect response model. The first approach traces back to a paper by Segre (1) and its application was popularized by Holford and Sheiner (2); indirect response models were introduced by Jusko's group (3). (omitted)

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Determination of Enalapril in Human Plasma by High Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry

  • Yoon, Kyung-Hwan;Kim, Won;Park, Jong-Sei;Kim, Hie-Joon
    • Bulletin of the Korean Chemical Society
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    • 제25권6호
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    • pp.878-880
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    • 2004
  • Revered-phase LC-electrospray ionization mass spectrometry was used to selectively determine enalapril from plasma with minimal sample preparation. Detection limit of the method was 1 ng/mL. Precision (within day and between days) and accuracy of the method at various concentrations were acceptable. The analytical technique was used for pharmacokinetic studies after administration of enalapril to human test subjects.

마이크로에멀젼으로 제제 설계된 피록시캄 외용제의 약물동력학적 특성 및 약효 평가 (Pharmacokinetic and Pharmacological Evaluation of Topical Microemulsion Preparation Containing Piroxicam)

  • 윤범진;박은석;지상철
    • Biomolecules & Therapeutics
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    • 제7권1호
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    • pp.54-58
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    • 1999
  • The pharmacological activities and pharmacokinetic aspects of a topical microemulsion (KDPM) containing 0.5% piroxicam were evaluated after its topical application compared with a commercially available 0.5% piroxicam gel (R gel). When the pharmacological activities were evaluated with the carrageenan-induced paw edema model, KDPM showed 55.6% edema inhibition, while R gel resulted in 37.1%. With the adjuvant-induced arthritis model, KDFM also resulted in the better pharmacological activities than R gel. The relative bioavailability of KDPM based on R gel was 176% in rabbits.

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Pharmacokinetic Study of Levosulpiride Tablets in Human Volunteers

  • Lee, Jung-Min;Yoon, Mi-Kyeong;Lee, Sung-Jae;Kim, Sun-Kyu;Choi, Young-Wook
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.240.3-241
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    • 2003
  • The purpose of this trial was to determine pharmacokinetic parameters and to characterize bioavailability of levosulpiride after oral administration in Korean healthy male volunteers. Thirty subjects were received a single oral dose of a tablet (Isomeric$\^$\ulcorner/) containing 25 mg of levosulpiride. The plasma concentrations of levosulpiride were measured by a validated FLD-HPLC method and compared with those reported in the literature. Levosulpride was absorbed slowly, revealing peak concentrations between 4 and 6 hr after oral administration. (omitted)

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Pharmacokinetic and Pharmacodynamic Characterization of Gliclazide in Healthy Volunteers

  • Kim, Ho-Soon;Yun, Min-Hyuk;Kwon, Kwang-Il
    • Archives of Pharmacal Research
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    • 제26권7호
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    • pp.564-568
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    • 2003
  • Pharmacokinetic and pharmacodynamic properties of gliclazide were studied after an oral administration of gliclazide tablets in healthy volunteers. After an overnight fasting, gliclazide tablet was orally administered to 11 volunteers; Additional 10 volunteers were used as a control group (i.e., no gliclazide administration). Blood samples were collected, and the concentration determined for gliclazide and glucose up to 24 after the administration. Standard pharmacokinetic analysis was carried out for gliclazide. Pharmacodynamic activity of the drug was expressed by increase of glucose concentration ($\Delta$PG), by area under the increase of glucose concentration-time curve ($AUC_{$\Delta$PG}$) or by the difference in increase of glucose concentration ($D_{$\Delta$PG}$) at each time between groups with and without gliclazide administration. Pharmacokinetic analysis revealed that $C_{max}, T_{max}$, CL/F (apparent clearance), V/F (apparent volume of distribution) and half-life of gliclazide were $4.69\pm1.38 mg/L, 3.45\pm1.11 h, 1.26\pm0.35 L/h, 17.78\pm5.27 L, and 9.99\pm2.15 h$, respectively. When compared with the no drug administration group, gliclazide decreased significantly the $AUC_{$\Delta$PG}$ s at 1, 1.5, 2, 2.5, 3 and 4 h (p<0.05). The $\Delta$PGs were positively correlated with $AUC_{gliclazide}$ at 1 and 1.5 h (p<0.05), and the correlation coefficient was maximum at 1 h (r = 0.642) and gradually decreased at 4 h after the administration. The $AUC_{$\Delta$PG}$s were positively correlated with $AUC_{gliclazide}$ at 1, 2, 3 and 4 h (p<0.05), and the maximum correlation coefficient was obtained at 2 h (r=0.642) after the administration. The $D_{$\Delta$PG}$ reached the maximum at 1 h, remained constant from 1 h to 3 h, and decreased afterwards. Therefore, these observations indicated that maximum hypoglycemic effect of gliclazide was reached at approximately at 1.5 h after the administration and the effect decreased, probably because of the homeostasis mechanism, in health volunteers.

한국재래산양에서 Enrofloxacin의 혈청내 항균효과와 체내동태 (Serum bactericidal activity and disposition kinetics of enrofloxacin in Korean native goats)

  • 윤효인;김무열;박승춘
    • 대한수의학회지
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    • 제37권2호
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    • pp.321-330
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    • 1997
  • Enrofloxacin is one of the second-generation quinolones which have been widely used to treat bacterial infections in various species including chicken, pig, horse and cattle. The objective of the present study was to describe the serum bactericidal activity(SBA) of enrofloxacin, its pharmacokinetic behaviors after intramuscular or intravenous administration to Korean native goats in the dose rate of 5mg/kg b.w. The results obtained through this study were as follows : 1. Sera collected from both sexes of Korean native goats administered 5mg/kg i.v. or i.m. showed potent antibacterial activities up to the 12 hours by way of the serum bactericidal activity. 2. Concentrations of enrofloxacin in the biological samples were measured by high-performance liquid chromatography(HPLC) so as to study pharmacokinetic characteristics. For detection of enrofloxacin, 10% TCA was optimal for protein precipitation and the mobile phase was 0.01M citric acid/methanol/acetonitrile(7/2/1, pH 3.5) with solid phase being the $C_{18}$ reversephase column and detection wavelength being 278nm. The limit of detection of enrofloxacin on HPLC was $0.05{\mu}g/ml$. 3. Pharmacokinetic profile of enrofloxacin administered 5mg/kg i.v. in Korean native goats was best described by two-compartment open model and that administered i.m. the same rate by one-compartment model. There were no sex differences in pharmacokineticl parameters. In conclusion, enrofloxacin showed potent in vivo antibacterial activity and excellent pharmacokinetic properties in Korean native goats, hence it may be used as a potential antibacterial in the veterinary clinical settings.

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