• 제목/요약/키워드: Controlled Release

검색결과 584건 처리시간 0.03초

Albumin Release from Biodegradable Hydrogels Composed of Dextran and Poly(Ethylene Glycol) Macromer

  • Kim, In-Sook;Jeong, Young-Il;Kim, Do-Hoon;Lee, Yun-Ho;Kim, Sung-Ho
    • Archives of Pharmacal Research
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    • 제24권1호
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    • pp.69-73
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    • 2001
  • Biodegradable hydrogels based on glycidyl methacrylate dextran (CMD) and dimethacrylate poly(ethylene glycol) (DMP) were proposed for colon-specific drug delivery. GMD was synthesized by coupling of glycidyl methacylate with dextran in the presence of 4-(N, N-dimethylamino)pyridine (DMAP) using dimethylsulfoxide as a solvent. Methacrylate-terminated poly (ethylene glycol) (PEG) macromer was prepared by the reaction of PEG with methacryloyl chloride. CMD/DMP hydrogels were prepared by radical polymerization of phosphate buffer solution (0.1 M, pH 7.4) of GMD and DMP using ammonium peroxydisulfate (APS) and UV as initiating system. The synthetic GMD, DMP and GMD/DMP hydrogels were characterized by fourier transform infrared (FT-lR) spectroscopy. The FITC-albumin loaded hydrogels were prepared by adding FITC-albumin solution before UV irradiation. Swelling capacity of GMD/DMP hydrogels was controlled not only by molecular weight of dextran, but also by incorporation ratio of DMP Degradation of the hydrogels has been studied in vitro with dextranase. FITC-albumin release from the GMD/DMP hydrogels was affected by molecular weight of nextran and the presence of dextranase in the release medium.

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건축물 제배연시나리오 작성을 위한 구획실 발열특성 연구 (Study on Characteristics of Heat Release Rate in Compartment of Building for Scenario of Smoke Management)

  • 김정엽;신현준
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.398-403
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    • 2009
  • The theoretical bases on characteristics of heat release rate in compartment of building for scenario of smoke management are introduced and the numerical applications to simple compartment model are carried out. The growth stage which is important for smoke management design is modelled as t-squared fire curve including fire growth coefficient with related to growth rate. The conditions for the happening of flashover is presented such as $600^{\circ}C$ of temperature or $20kW/m^2$ of radiation heat flux. After the flashover happen, the fire in compartment changes to fully developed fire having the characteristics of ventilation-controlled fire. As the result of numerical analysis to simple compartment model, the time to reach 900K under ceiling for condition of medium growth is twice for condition of fast growth.

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추나요법과 근막이완요법의 척추측만증 환자 4례에 대한 증례 보고 (Chuna Therapy and Myofascial Release Technique for the Pain Relief and Cobb's Angle Improvement in Patients with Scoliosis: Case Report)

  • 이상영;김기덕;박수곤;김민성;황춘호;조형준;설재욱
    • 척추신경추나의학회지
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    • 제7권1호
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    • pp.59-65
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    • 2012
  • Objectives: This study is designed to report the valid result of complex of Chuna Therapy and Myofascial Release Technique(MRT) on scoliosis patients. Methods: The correction program for scoliosis takes 3 month per case. Chuna Therapy and MRT were given once a week and other oriental medicine care was given twice a week to care the complications of scoliosis. The Cobb's angle(by X-ray, Full spine view) and Visual analogue scale(VAS) were evaluated before and after the treatments. Results: After the program, both of Cobb's angle and VAS decreased. Conclusions: Though it is a case report, we found Chuna Therapy and MRT might have valid effect on scoliosis patients. Further rigorous case series and controlled trials are warranted.

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페닐프로피온산계 해열진통제 고형지질나노입자의 입도분포와 약물봉입 및 용출특성 (Particle Size Distribution, Drug Loading Capacity and Release Profiles of Solid Lipid Nanoparticles of Phenylpropionic Acids)

  • 김윤선;김길수
    • Journal of Pharmaceutical Investigation
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    • 제28권4호
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    • pp.249-255
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    • 1998
  • Solid Lipid Nanoparticle(SLN), one of the colloidal carrier systems, has many advantages such as good biocompatibility, low toxicity and stability. In this paper, the effects of drug lipophilicity and surfactant on the drug loading capacity, particle size and drug release profile were examined. SLNs were prepared by homogenization of melted lipid dispersed in an aqueous surfactant solution. Ketoprofen, ibuprofen and pranoprofen were used as model drugs and tweens and poloxamers were tested for the effect of surfactant. Mean particle size of prepared SLNs was ranged from 100 to 150nm. The drug loading capacity was improved with the most lipophilic drug and low concentration of surfactant. Particle size and polydispersity of SLNs were changed according to the used lipid and surfactant. The rates of drug release were controlled by the loading drug and surfactant concentration. SLN system with effective drug loading efficiency and proper particle size for the intravenous or oral formulation can be prepared by selecting optimum drug and surfactant.

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제어 방출협 캅토프릴 마이크로캅셀의 제조 및 용출 특성 (The Preparation of Controlled-Release Microcapsules for Captopril and Their Dissolution Characteristics)

  • 최현순;장혁;이계원;지웅길
    • Journal of Pharmaceutical Investigation
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    • 제28권1호
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    • pp.7-13
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    • 1998
  • The captopril microcapsules were prepared and were investigated by measuring their size distribution using Scanning Electron Microscopy(SEM) and dissolution of captopril. Cetyl alcohol microcapsules prepared by emulsion melted-cooled method with various ratios of drug to cetyl alcohol were spherical and uniform. The release rate of cetyl alcohol microcapsules was decreased proportionally as the content of cetyl alcohol increased but, the particle size of microcapsules was increased. The surface of cetyl alcohol microcapsules was comparatively rough as drug content increased. Pellet type microcapsules were prepared using fluidized-bed coating system by spraying captopril solution on nonpareil-seeds followed by applying $Eudragit^{\circledR}$ RS solution containing propylene glycol as a plasticizer. The release rate of drug from pellet type microcapsules decreased as the content of $Eudragit^{\circledR}$ RS increased.

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A Brief Replication Study Comparing Stimulants and Non-Stimulants for Attention-Deficit/Hyperactivity Disorder Treatment with a Focus on the Compliance, Efficacy, and Satisfaction

  • Roh, Hyosung;Kim, Bongseog
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • 제32권1호
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    • pp.10-16
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    • 2021
  • Objectives: The aim of this study was to compare the compliance, efficacy, and satisfaction associated with methylphenidate and atomoxetine for treating attention-deficit/hyperactivity disorder (ADHD). Methods: The subjects were 44 patients who met the Diagnostic and Statistical Manual of Mental Disorder-5 diagnostic criteria for ADHD and were treated with methylphenidate or atomoxetine. The methylphenidate formulations included immediate release (IR), extended release (ER), and osmotic-controlled release oral delivery system (OROS). Patients and parents reported the average number of days per week the medication was taken. Efficacy was assessed using the ADHD Rating Scale. Satisfaction with medication scale (SAMS)-parent report form and SAMS-self-report form were used to evaluate parents' and patients' satisfaction, respectively. Results: Patients and parents were more satisfied with methylphenidate than with atomoxetine. There were no significant differences in the compliance with and efficacy of methylphenidate and atomoxetine. Compliance with methylphenidate IR and ER was markedly lower than that with OROS methylphenidate or atomoxetine. Conclusion: Methylphenidate OROS formulation can be considered a suitable option given its high rates of compliance, satisfaction, and efficacy.

The Effects of Myofascial Trigger Point Release and Mobility Exercise on Pain and Functions in Patient with Rotator Cuff Tendinopathy

  • Shin, Beom-Cheol;Choi, Wonjae;Jung, Jihye;Lee, Seungwon
    • Physical Therapy Rehabilitation Science
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    • 제11권2호
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    • pp.269-278
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    • 2022
  • Objective: The aim of this study was to evaluate the effects on pain and function of patients with rotator cuff tendinopathy when applying trigger point of infraspinatus and teres minor to myofascial trigger point release (MFR) plus mobility exercise and MFR. Design: A randomized controlled trial. Methods: The total participants were 30patients and were separated to MFR plus mobility exercise group(n=15) and MFR group (n=15) according to the randomized treatment method. The MFR was performed at two infraspinatus tampon points and one teres minor tampon point for twice a week for 4 weeks and the treatment time was 6 minutes 20 seconds in each position. The MFR group also carried out the myofascial trigger point release in the same way as the MFR plus mobility exercise group. Results: The MFR plus mobility exercise group significantly reduced objective and subjective pain (p<0.05). The range of motion of the shoulder joint flexion and external rotation, Quick-Disability of the Arm, shoulder and Hand, and Shoulder Pain and Disability Index were significantly improved in the group to which MFR plus mobility exercise was applied (p<0.05). Conclusions: These results confirmed that MRF plus mobility exercise is more effective in relieving shoulder pain and improving function in rotator cuff tendinopathy.

A Comparative Functionality Evaluation of Paulownia Wood Storage Boxes and Acid-free Archival Boxes to Store the Annals of Joseon Dynasty - Indoor and Outdoor Temperature and Relative Humidity Controls, and Heat Release Rate -

  • Park, Hae Jin;Kim, Seong Eun;Lee, Jin Kyung;Chung, Yong Jae
    • 보존과학회지
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    • 제38권1호
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    • pp.72-79
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    • 2022
  • A paulownia wood has been widely used with various advantages as its low weight, permeability, convenient workability and aesthetic patterns for a long time. However, the related empirical researches and simultaneous evaluations of functionality are insufficient compared with acid-free archival boxes for now. In this study, the indoor and outdoor temperature and relative humidity control and heat release rate were evaluated under the controlled and uncontrolled circumstance in 2018. The paulownia wood storage box showed superior control effect of relative humidity than the acid-free archival box in constantly uncontrolled environment. Also, the possibility of the flame diffusion from the surface of the materials was higher for the paulownia materials, and the acid-free archival box showed more dangerous patterns in the early stages of the fire.

Intravascular Tumour Targeting of Aclarubicin-loaded Gelatin Microspheres Preparation biocompatibility and biodegradability

  • Lee, Kang-Choon;Koh, Ik-Bae
    • Archives of Pharmacal Research
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    • 제10권1호
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    • pp.42-49
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    • 1987
  • This study is to evaluate the potential use of aclarubicin-loaded gelatin microspheres as an intravascular biodegradable drug delivery system for the regional cancer therapy. The diameter of the microspheres prepared by water in oil emulsion polymerization could be controlled by adjusting the stirring rate in the range of 10-50 $\mu$m : D(in $\mu$m) = -73.8 log (rpm) + 262.7. The addition of proteolytic enzyme increased the in vitro aclarubicin release but it did not change the amount of the initial burst release which reached about 45%. Microspheres injected intravenously into the mouse tail vein embolized only to the lung when observed by fluorescence microscopy. From histological examination following injection of gelatin microspheres into mouse femoral muscle, mild inflammation was observed from the appearance of neutrophils after 2 days and rapid repair process was confirmed thereafter. Biodegradation process of gelatin microspheres lodged on the pulmonary capillary bed was followed up by microscopic observation; degradation was taking place by about 36 hrs, followed by severe damage on the spheerical shape and microspheres was no longer found 10 days after injection.

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Thermal Process for Enhancing Mechanical Strength of PLGA Nanoparticle Layers on Coronary Stents

  • Joo, Jae-Ryang;Nam, Hye-Yeong;Nam, So-Hee;Baek, In-Su;Park, Jong-Sang
    • Bulletin of the Korean Chemical Society
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    • 제30권9호
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    • pp.1985-1988
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    • 2009
  • Poly (lactic-co-glycolic acid) (PLGA) nanoparticles loading paclitaxel have been deposited on coronary stents by self-assembling properties of colloidal particles. The layers of the nanoparticles were enhanced to a sufficient mechanical strength by a thermal process under the proper temperature and humidity conditions. In vitro release studies proved the controlled paclitaxel release of the nanoparticle layers. This technique gives rise to a new range of applications for nanoparticles and drug-eluting stents.