• 제목/요약/키워드: Drug Distribution

검색결과 554건 처리시간 0.032초

Robust Inference for Testing Order-Restricted Inference

  • Kang, Moon-Su
    • 응용통계연구
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    • 제22권5호
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    • pp.1097-1102
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    • 2009
  • Classification of subjects with unknown distribution in small sample size setup may involve order-restricted constraints in multivariate parameter setups. Those problems makes optimality of conventional likelihood ratio based statistical inferences not feasible. Fortunately, Roy (1953) introduced union-intersection principle(UIP) which provides an alternative avenue. Redescending M-estimator along with that principle yields a considerably appropriate robust testing procedure. Furthermore, conditionally distribution-free test based upon exact permutation theory is used to generate p-values, even in small sample. Applications of this method are illustrated in simulated data and read data example (Lobenhofer et al., 2002)

Determination of Methamphetamine and its Metabolite Amphetamine in Biological Fluids from 11 Fatal Gases

  • Yoo, Young-Chan;Chung, Hee-Sun;Choi, Hwa-Kyung
    • Archives of Pharmacal Research
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    • 제16권3호
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    • pp.175-179
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    • 1993
  • Gas chromoatography with flame ionization detector (FID) along with mass spectrometry (GC/MS) were used for the screening and quantification of methamphetamine (MA) and its major metabolite, amphetamine (AM0, in blood and urine in eleven fatal cases in which MA abuse was suspected. Postmortem blood MA varied from $0.5-30.2\;\mu{g/ml}$, while Am levels ranged from none detected (6 of 11 cases) to 4.8 .mu.g/ml. Additionally, distribution studies were performed in three of these cases in which tissue smaples were available for evaluation. Liver contained the highest ocncentration of MA among the tissu samples. In eight of the eleven cases, when no other direct cause of death was evident (i.e. 3 cases of traumatic dath0, either no blood AM was found or the ratio of MA/AM was 3.4 or greater. These data are consistent with acute MA use followed by death due to acute drug intoxication or by the occurrence of hypersensitivity and reverse seen in cases of chronic drug abuse.

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유전자 마커를 이용한 하수오, 백수오 및 이엽우피소 종 판별법 개발 (Development of Primer Sets for the Detection of Polygonum multiflorum, Cynanchum wilfordii and C. auriculatum)

  • 김규헌;김용상;김미라;이호연;이규하;김종환;성락선;강태선;이진하;장영미
    • 한국식품위생안전성학회지
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    • 제30권3호
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    • pp.289-294
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    • 2015
  • 본 연구에서는 건강기능성 식품원료로서 이용 빈도가 증가하고 있는 하수오, 백수오 및 이엽우피소에 대한 종 특이 프라이머를 개발하였다. 개발된 종 특이 프라이머는 하수오, 백수오 및 이엽우피소에 대해 원물뿐만 아니라 육안 확인이 어려운 가공식품 등을 대상으로 사용원료의 진위여부를 빠르고 정확하게 확인할 수 있었다. 따라서 본 연구에서 개발한 종 특이 PCR방법은 기존의 일반 프라이머를 사용하는 방법이 가지고 있는 식품 적용 한계를 극복할 수 있을 것이라고 판단하였다.

단단한 종양 안에 수동 조준된 약물의 전달에 관한 확산에 기초한 모델 이론 (A Diffusion-based Model Theory of Passive-Targeted Drug Delivery in Solid Tumors)

  • 최준혁;강남룡;최상돈
    • 한국의학물리학회지:의학물리
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    • 제18권3호
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    • pp.161-166
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    • 2007
  • 공모양의 단단한 종양안에서 수동조준된 약물의 전달에 관한 모델이론이 적절한 경계조건과 초기조건하에서 픽의 확산법칙으로부터 유도된다. 종양안의 농도는 초기값이 일정하면 시간과 지름의 함수로 나타난다. 생각실험(사고실험)으로부터 예측되는 바와 같이, 농도는 시간이 경과함에 따라 평형값에 접근한다. 시간에 따른 농도의 변화는 조직안의 약물의 확산계수, 종양의 크기, 주입된 약물의 양, 경계면에서의 농도의 물매(gradient)에 의해 결정된다.

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SMEDDS를 이용한 난용성 약물의 용출율 향상 (Improvement of Dissolution Rate of Poorly Water Soluble Drug Using Self-microemulsifying Drug Delivery System)

  • 김계현;이윤석;배준호;지상철;박은석
    • Journal of Pharmaceutical Investigation
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    • 제29권1호
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    • pp.37-45
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    • 1999
  • ABSTRACT-A self-microemulsifying drug delivery system (SMEDDS) was developed to enhance the solubility and dissolution rate of poorly water soluble drug, biphenyl dimethyl dicarboxylate, DDB. The system was optimized by evaluating the solubility of DDB and the microemulsion existence range after the preparation of microemulsions with varying compositions of triacetin and surfactant-cosurfactant mixtures (Labrasol as surfactant (S) and the combination of Transcutol, Cremophor RH 40 and Plurol oleique as cosurfactant (CoS)). SMEDDS in this study markedly improved the solubility of DDB in water up to 10 mg/ml and the size of the o/w microemulsion droplets measured by dynamic light scattering showed a narrow monodisperse size distribution with an average diameter less than 50 nm. The microemulsion existing range is increased proportional to the ratio of S/CoS, however, it decreased remarkably as the oil content was more than 20%. In vitro dissolution study of SMEDDS showed a significantly increased dissolution rate of DDB in water (> 12 fold over DDB powder), and SMEDDS also had significantly greater permeability of DDB in Caco-2 cell compared to powders.

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Development of Polymeric Blend Microspheres from Chitosan-Hydroxypropylmethyl Cellulose for Controlled Release of an Anti-Cancer Drug

  • Reddy, Lakshmi C. Narayana;Reddy, Rama Subba P.;Rao, Krishna K.S.V.;Subha, M.C.S.;Rao, Chowdoji K.
    • 대한화학회지
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    • 제57권4호
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    • pp.439-446
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    • 2013
  • Chitosan (CS) and hydroxypropylmethyl cellulose (HPMC) blend microspheres were prepared by water-in-oil emulsion technique and were loaded with an anti-cancer drug 5-fluorouracil (5-FU). CS-HPMC microspheres were characterized by Fourier transform infrared spectroscopy to confirm the cross-linking reaction. Scanning electron microscopy (SEM) was also used to assess the surface morphology of particles prepared. The quantity of release of 5-FU from the microspheres have been studied in terms of blend composition and amount of cross-linking agent. Differential scanning calorimetry and X-ray diffraction techniques indicated a uniform distribution of 5-FU particles in microspheres, whereas SEM suggested the spherical structure of the microspheres with slight rough surface. The in vitro drug release indicated that the particle size and release kinetics depend upon blend composition, amount of cross-linking agent used and amount of 5-FU present in the microspheres.

니코틴과 트리암시놀론 아세토니드를 함유하는 생분해성 마이크로스피어의 제조시 분무건조법과 용매증발법의 비교 (Comparative Study of Spray Drying Method and Solvent Evaporation Method for Preparation of Biodegradable Microspheres Containing Nicotine and Triamcinolone Acetonide)

  • 박선영;조미현;이종화;김동우;지웅길
    • Journal of Pharmaceutical Investigation
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    • 제31권4호
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    • pp.257-263
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    • 2001
  • The microspheres have been developed as a new drug delivery system. Although many particulate drug carriers, such as liposome, niosome and emulsion, have been introduced, injectable and biodegradable microspheres appears to be a particularly ideal delivery system because the local anesthesia is not necessary for the insertion of large implants and for the removal of the device after the drug release is finished. Biodegradable microspheres with nicotine and triamcinolone acetonide are prepared and evaluated. As biodegradible polymers, PLA (M.W. 15,000, PLA-0015), PLGA (M.W. 17,000, RG 502) and PLGA (M.W. 8,600, RG 502H) are used. This study attempted to prepare and evaluate the nicotine and triamcinolone acetonide-incorporated microspheres, which were prepared by two methods, solvent-evaporation and spray-drying methods. The microspheres, as a disperse system for injections, were evaluated by particle size, size distribution, entrapment efficiency, and in vitro drug release patterns. The differences of preparation method, partition coefficient, types of polymer, and preparation conditions of microspheres influence the particle size, entrapment efficiency, and in vitro drug release patterns.

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Simultaneous Evaluation of Cellular Vitality and Drug Penetration in Multicellular Layers of Human Cancer Cells

  • Al-Abd Ahmed Mohammed;Lee Joo-Ho;Kuh Hyo-Jeong
    • Journal of Pharmaceutical Investigation
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    • 제36권5호
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    • pp.309-314
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    • 2006
  • The multicellular layers(MCL) of human cancer cells is a three dimensional(3D) in vitro model for human solid tumors which has been used primarily for the assessment of avascular penetration of anti-cancer drugs. For anti-cancer drugs with penetration problem, MCL represents a good experimental model that can provide clinically relevant data. Calcein-AM is a fluorescent dye that demonstrates the cellular vitality in a graded manner in cancer cell culture system. In the present study, we evaluated the use of calcein-AM for determination of anti-proliferative activity of anti-cancer agents in MCL model of DLD-1 human colorectal cancer cells. Optical sectioning of confocal imaging was compromised with photonic attenuation and penetration barrier in the deep layers of MCL. By contrast, fluorescent measurement on the cryo-sections provided a feasible alternative. Cold pre-incubation did not enhance the calcein-AM distribution to a significant degree in MCL of DLD-1 cells. However, the simultaneous determination of drug penetration and cellular vitality appeared to be possible in drug treated MCL. In conclusion, these data suggest that calcein-AM can be used for the simultaneous determination of drug-induced anti-proliferative effect and drug penetration in MCL model.

Interactions of Cationic Drugs and Cardiac Glycosides at the Hepatic Uptake Level: Studies in the Rat in Vivo, Isolated Perfused Rat Liver, Isolated Rat Hepatocytes and Oocytes Expressing oatp2

  • Dirk K.F.Meijer;Jessica E.van Montfoort
    • Archives of Pharmacal Research
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    • 제25권4호
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    • pp.397-415
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    • 2002
  • This paper deals with a crucial mechanism for interaction of basic drugs and cardiac glycosides at the hepatic uptake level. Available literature data is provided and new material is presented to picture the differential transport inhibition of bulky (type2) cationic drugs by a number of cardiac glycosides in rat liver. It is shown that the so called organic anion transporting peptide 2 (oatp2) is the likely interaction site: differential inhibition patterns as observed in oocytes expressing oatp2, could be clearly identified also in isolated rat hepatocytes, isolated perfused rat liver and the rat in vivo. The anticipation of transport interactions at the hepatic clearance level should be based on data on the relative affinities of interacting substrates for the transport systems involved along with knowledge on the pharmacokinetics of these agents as well as the chosen dose regimen in the studied species. This review highlights the importance of multispecific tranporter systems such as OATP, accommodating a broad spectrum of organic compounds of various charge, implying potential transport interactions that can affect body distribution and organ clearance.