• 제목/요약/키워드: release treatment

검색결과 1,685건 처리시간 0.03초

BCNU 함유 PLGA 웨이퍼의 제조와 생체외 방출거동 (Preparation of BCNU-loaded PLGA Wafers and In Vitro Release Behavior)

  • 성하수;문대식;강길선;이정식;이해방
    • 폴리머
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    • 제26권1호
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    • pp.128-138
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    • 2002
  • 종양부위 또는 종양을 수술로 제거한 부위에 직접 이식하여 항암제를 투여함으로써 종양 또는 종양재발을 억제하는 악성뇌종양치료에 이용하기 위한 국소서방성 항암제제로서 항암제 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, Carmustine)가 함유된 poly(D,L-lactide-co-glycolide) (PLGA, 락타이드와 글리콜라이드 몰비 75 : 25) 미분말을 제조하여 웨이퍼로 성형하였다. BCNU가 함유된 PLGA 미분말은 분사건조법에 의해 제조하였으며 주사전자현미경으로 관찰한 결과 제조된 미분말은 미립구의 형태를 나타내었다. XRD와 DSC를 통하여 PLGA에 포접된 BCNU의 결정성이 현저히 감소하였음을 확인하였다. 생체외 방출시험조건에서 BCNU의 방출경향은 PLGA의 분자량 및 농도, BCNU의 함량 등에 의존하였으며 초기 burst effect 이후 거의 0차 방출의 경향으로 8주 이상 지속적인 방출경향을 나타내었다. 방출시험기간 동안 웨이퍼의 형태변화를 관찰하고 방출시험액의 pH 변화를 측정함으로써 BCNU의 함량이 증가할수록 PLGA의 수화와 분해가 촉진됨을 확인하였다.

유동층 코팅기를 이용한 염산알푸조신의 서방형 과립 설계 및 제조 (Formulation and Preparation of Sustained Release Pellet for Alfuzosin HCI Using Fluid-bed coater)

  • 나진상;윤양노;서희;정상영;박은석;황성주;신병철;김성훈;조선행
    • Journal of Pharmaceutical Investigation
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    • 제38권6호
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    • pp.387-392
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    • 2008
  • Alfuzosin, an Alphal-adrenoceptor antagonist is used for the treatment of patients with voiding and in a lesser extent storage lower urinary tract symptoms (LUTS) associated to benign prostatic hyperplasia (BPH). The objective of this study was to formulate sustained release alfuzosin HCl granules and assess their formulation variables. The $Eudragit^{(R)}$ as a polymer, sustained release membrane, and dibutyl sebacate (DBS) as a plasticizer were used. Multi-coated alfuzosin HCl delivery systems composed of sugar sphere, various excipients, $Eudragit^{(R)}$ and HPMC (hydroxy propyl methyl cellulose), Cellulose Acetate were prepared by fluid-bed coater. Membrane layer were used $Eudragit^{(R)}$ RS PO and NE 30D. And the alfuzosin HCl coated beads were coated immediate release drug layer for initial burst. Its dissolution test was carried out compared to conventional products ($XATRAL^{(R)}$ XL). The release rate of drug from coated beads was higher than that from $XATRAL^{(R)}$ XL in pH 6.8.

Development of Drug-Loaded PLGA Microparticles with Different Release Patterns for Prolonged Drug Delivery

  • Choi, Yeon-Soon;Joo, Jae-Ryang;Hong, Areum;Park, Jong-Sang
    • Bulletin of the Korean Chemical Society
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    • 제32권3호
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    • pp.867-872
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    • 2011
  • For the prolonged delivery and sustained release rates of low molecular weight drugs, poly(lactic-co-glycolic acid) (PLGA) microparticles containing the drug SKL-2020 have been investigated. On increasing polyvinyl alcohol (PVA) concentration (from 0.2% to 5%), the size of microparticles decreased (from $48.02{\mu}m$ to $10.63{\mu}m$) and more uniform size distribution was noticeable due to the powerful emulsifying ability of PVA. A higher drug loading (from 5% to 20%) caused a larger concentration gradient between 2 phases at the polymer precipitation step; this resulted in decreased encapsulation efficiency (from 34.19% to 25.67%) and a greater initial burst (from 61.71% to 70.05%). SKL-2020-loaded PLGA microparticles prepared with different fabrication conditions exhibited unique release patterns of SKL-2020. High PVA concentration and high drug loading led to an initial burst effect by rapid drug diffusion through the polymer matrix. Since PLGA microparticles enabled the slow release of SKL-2020 over 1 week in vitro and in vivo, more convenient and comfortable treatment could be facilitated with less frequent administration. It is feasible to design a release profile by mixing microparticles that were prepared with different fabrication conditions. By this method, the initial burst could be repressed properly and drug release rate could decrease.

글리콜라이드 단량체를 함유한 BICNU 함유 다중층 PLGA웨이퍼의 제조 및 특성결정 (Preparation and Characterization of BICND-loaded Multi-Layer PLGA Wafer Containing Glycolide Monomer)

  • 채강수;이진수;정제교;조선행;이해방;강길선
    • 폴리머
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    • 제28권4호
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    • pp.335-343
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    • 2004
  • 카뮤스틴 (1,3-bis(2-chloroethy1-nitrosourea, BICNU)은 뇌종양 치료를 위하여 임상적으로 사용되는 약물로 짧은 생물학적 반감기를 가지고 있어 장기방출에 적합하지 않다. 하지만, poly(D,L-lactide-co-glycolide) (PLGA)는 벌크 분해 특성으로 인해 약물의 장기방출에 유용하며, PLGA의 유도체인 글리콜라이드 단량체는 독성이 없고 PLGA와 유사한 생분해성을 가지고 있어 BICNU의 방출조절에 이용된다. 이 실험에서 BICNU를 함유한 PLGA 웨이퍼는 일반적인 직접압축법에 의해 제조한 후 BICNU의 방출거동과 웨이펴의 분해속도를 전자주사현미경, 핵자기공명장치 그리고 젤투과크로마토그래피를 통해 관찰하였다. 또한, 글리콜라이드 단량체의 함량변화에 따른 다중층 웨이퍼를 제조하여 단일층 웨이퍼와의 방출거동을 비교하였다. 이러한 결과들로부터 BICNU를 함유한 PLGA 웨이퍼의 약물방출은 BICNU와 글리콜라이드 단량체의 함량이 증가할수록 증가하였고, 다중층 웨이퍼에서 외부층의 글리콜라이드 단량체와 BICNU가 약물방출 거동과 분해속도에 영향을 미친다는 것을 확인하였다.

Can manipulation under anesthesia alone provide clinical outcomes similar to arthroscopic circumferential capsular release in primary frozen shoulder (FS)?: the necessity of arthroscopic capsular release in primary FS

  • Lee, Seung-Jin;Jang, Jun-Hyuk;Hyun, Yoon-Suk
    • Clinics in Shoulder and Elbow
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    • 제23권4호
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    • pp.169-177
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    • 2020
  • Background: We evaluated the need for arthroscopic capsular release (ACR) in refractory primary frozen shoulder (FS) by comparing clinical outcomes of patients treated with ACR and manipulation under anesthesia (MUA). Methods: We assessed patients with refractory primary FS, 57 patients (group A) who were treated with MUA and 22 patients (group B) who were treated with ACR. In group A, manipulation including a backside arm-curl maneuver was performed under interscalene brachial block. In group B, manipulation was performed only to release the inferior capsule before arthroscopic circumferential capsular release, which was carried out for the unreleased capsule after manipulation. Pain, range of shoulder motion, and American Shoulder and Elbow Surgeons score were recorded at 1 week, 3 months, 6 months, and 1 year after surgery. We compared outcome variables between treatment groups and between diabetics and non-diabetics and also evaluated the numbers of patients receiving additional intra-articular steroid injection. Results: Outcome variables at 3 months after surgery and improvements in outcome variables did not differ between groups. Group A showed significantly better results than group B in the evaluation of pain and range of motion at 1 week. Diabetics showed comparable outcomes to non-diabetics for most variables. Eleven patients required additional steroid injections between 8 to 16 weeks after surgery: 12.2% in group A, 18.2% in group B. Additional injections were given three times more often in diabetics compared to non-diabetics. Conclusions: MUA alone can yield similar clinical outcomes to ACR in refractory FS.

친환경 딸기 재배 농가에서 칠레이리응애를 이용한 점박이응애 생물적 방제 (Biological Control of Two Spotted Spider Mite (Tetranychus urticae) by the Predatory Mite (Phytoseiulus persimilis) in Sustainable Strawberry Fields)

  • 김도익;김선곤;신길호;서종분;최경주;임경호;김상수
    • 한국유기농업학회지
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    • 제14권3호
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    • pp.315-323
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    • 2006
  • 전남지역 딸기 친환경재배농가에서 큰 피해를 주고 있는 점박이응애를 방제하기 위해 천적인 칠레이리응애의 방사량과 횟수를 검정하고, 농가에서의 실증효과를 시험하였다. 칠레이리응애를 1회 방사하였을 때 방사 4주째부터 밀도가 올라가기 시작하였으며, 2회 방사시에는 7주 이후 8주째부터 밀도 증가가 이루어 졌다. 그러나 3회 방사하였을 때에는 조사기간 동안 점박이응애 밀도를 10마리 내외로 일정하게 유지시킬 수 있었다. 또한 칠레이리응애의 방사량도 1,000마리인 경우에는 생육 후기에 점박이응애의 밀도가 증가하여 방제효과가 낮았으며, 3,000마리를 방사하는 경우에는 2,000마리 처리구와 비슷한 밀도를 유지하는 것으로 보아 천적을 2,000마리 방사하여 점박이응애를 충분히 억제할 수 있었다. 함평 농가실증 시험의 무방사구에서 점박이응애는 3월 하순부터 발생하기 시작하여 이후 급격한 밀도 증가가 이루어졌다. 방사구에서는 칠레이리응애 밀도가 지속적으로 유지되어 점박이응애 밀도를 억제하였다. 보성 농가에서는 3월 상순에 방사구의 점박이응애 밀도가 상승함에 따라 칠레이리응애 밀도도 함께 상승하여 3월 하순에는 10엽당 50마리까지 증가하였다. 발생엽율은 천적 방사구에서는 높지 않았으나 무방사구에서는 초기 밞생이 확인된 이후 계속 상승하여 $10.5{\sim}75.5%$까지 올라갔다.

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Characteristics of $A_1\;and\;A_2$ Adenosine Receptors upon the Acetylcholine Release in the Rat Hippocampus

  • Kim, Do-Kyung;Lee, Young-Soo;Choi, Bong-Kyu
    • The Korean Journal of Physiology and Pharmacology
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    • 제2권1호
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    • pp.31-39
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    • 1998
  • As it has been reported that the depolarization induced acetylcholine (ACh) release is modulated by activation of presynaptic $A_1$ adenosine heteroreceptor and various lines of evidence suggest the $A_2$ adenosine receptor is present in the hippocampus. The present study was undertaken to delineate the role of adenosine receptors on the hippocampal ACh release. Slices from the rat hippocampus were equilibrated with $[^3H]choline$ and then the release amount of the labelled product, $[^3H]ACh$, which was evoked by electrical stimulation (rectangular pulses, 3 Hz, 2 ms, 24 mA, $5\;V/cm^{-1}$, 2 min), was measured, and the influence of various adenosine receptor-related agents on the evoked tritium outflow was investigated. And also, the drug-receptor binding assay was performed in order to confirm the presence of $A_1$ and $A_2$ adenosine receptors in the rat hippocampus. N-ethylcarboxamidoadenosine (NECA), a potent adenosine receptor agonist with nearly equal affinity at $A_1$ and $A_2$ adenosine receptors, in concentrations ranging from $1{\sim}30\;{\mu}M$, decreased the electrically-evoked $[^3H]ACh$ release in a concentration-dependent manner without affecting the basal rate of release. And the effect of NECA was significantly inhibited by 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 2 ${\mu}M$), a selective $A_1$ adenosine receptor antagonist, but was not influenced by 3,7-dimethyl-1-propargylxanthine (DMPX, 5 ${\mu}M$), a specific $A_2$ adenosine receptor antagonist. $N^6-cyclopentyladenosine$ (CPA), a selective $A_1$ adenosine receptor agonist, in doses ranging from 0.1 to 10 ${\mu}M$, reduced evoked $[^3H]ACh$ release in a dose-dependent manner without the change of the basal release. And the effect of CPA was significantly inhibited by 2 ${\mu}M$ DPCPX treatment. 2-P-(2-carboxyethyl)-phenethylamino-5'-N-ethylcarboxamidoadenosine hydrochloride (CGS-21680C), a potent $A_2$ adenosine receptor agonist, in concentrations ranging from 0.1 to 10 ${\mu}M$, did not alter the evoked ACh release. In the drug-receptor binding assay, the binding of $[^3H]2-chloro-N^6-cyclopentyladenosine$ ($[^3H]$CCPA) to the $A_1$ adenosine receptor of rat hippocampal membranes was inhibited by CPA ($K_i$ = 1.22 nM), NECA ($K_i=10.17 nM$) and DPCPX ($K_i=161.86 nM$), but not by CGS-21680C ($K_i=2,380 nM$) and DMPX ($K_i=22,367 nM$). However, the specific binding of $[^3H]CGS-21680C$ to the $A_2$ adenosine receptor was not observed. These results suggest that the $A_1$ adenosine heteroreceptor play an important role in evoked ACh release, but the presence of $A_2$ adenosine receptor is not confirmed in this study.

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허혈이 유발된 흰쥐 해마에서 Acetylcholine 유리에 미치는 Adenosine 수용체의 역할 (The Role of Adenosine Receptor on Acetylcholine Release from Ischemic-Induced Rat Hippocampus)

  • 최봉규;김도경;강헌;전재민;강연욱
    • 대한약리학회지
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    • 제32권2호
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    • pp.127-138
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    • 1996
  • The effects of adenosine analogues on the electrically-evoked acetylcholine(ACh) release and the influence of ischemia on the effects were studied in the rat hippocampus. Slices from the rat hippocampus were equilibrated with $0.1{\mu}M$ $[^3H]-choline$ and the release of the labelled product, $[^3H]-ACh$, was evoked by electrical stimulation(3 Hz, 2 ms, 5 $VCm^{-1}$ and rectangular pulses for 2 min), and the influence of various agents on the evoked tritiumoutflow was investigated. Ischemia(10 min with 95% $N_2$ + 5% $CO_2$) increased both the basal and evoked ACh release. These increases were abolished by glucose addition into the superfused medium, and they significantly inhibited either by 0.1 & $0.3{\mu}M$ TTX pretreatment or by removing $Ca^{++}$ in the medium. MK-801($1{\sim}10{\mu}M$), a specific NMDA receptor antagonist, and glibenclamide $(1{\mu}M)$, a $K^+-channel$ inhibitor, did not alter the evoked ACh release and nor did they affect the ischemia-induced increases In ACh release. However, polymyxin B(0.03 mg), a specific protein kinase C inhibitor, significantly inhibited the effects of ischemia on the evoked ACh release. Adenosine and $N^6-cyclopentyladenosine$ decreased the ACh release in a dose dependent manner in ischemic condition, though the magnitude of inhibition was far less than those in normal(normoxic) condition. However, the treatment with $5{\mu}M$ DPCPX, a potent $A_1-adenosine$ receptor antagonist, potentiated the ischemia-effect. These results indicate that the evoked-ACh release is potentiated by ischemia, and this process being most probably mediated by protein kinase C, and that the decreased effect of ACh release mediated by $A_1-adenosine$ receptor is significantly inhibited in ischemic state.

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흰쥐 뇌하수체 전엽세포에서 PKC나 cAMP에 의한 LH 분비 및 $LH{\beta}$ Subunit mRNA 증가에 미치는 $Ca^{++}$의 영향 (Effects of Extracellular $Ca^{++}$ on PKC or cAMP-stimulated Increases in LH Release and $LH{\beta}$ Subunit mRNA Levels in Rat Anterior Pituitary Cells)

  • 박덕배;김창미;천민석;유경자
    • 대한약리학회지
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    • 제32권3호
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    • pp.347-355
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    • 1996
  • 흰쥐 뇌하수체 전엽배양세포에서 PKC나 cAMP에 의한 LH 분비와 $LH{\beta}$subunit mRNA 증가과정에서 세포외 $Ca^{++}$의 역할을 검증하기 위하여 phorbol ester와 forskolin에 의해 촉진된 LH 분비와 $LH{\beta}$ subunit mRNA 수준에 미치는 EGTA와 verapamil의 영향을 조사하였다. Forskolin에 의해 촉진된 LH 분비와 $LH{\beta}$ subunit mRNA 수준은 $Ca^{++}$ chelator인 EGTA나 $Ca^{++}$ 채널차단제인 verapamil의 처리로 세포외부로부터 $Ca^{++}$의 이동을 억제시켰을때 모두 감소하였다. PMA에 의해 유도된 LH 분비는 EGTA와 verapamil 처리에 의해 영향을 받지 않았으나 PMA에 의해 촉진된 $LH{\beta}$ subunit mRNA는 억제되었다. 따라서 본 연구에 의하면 PKC 활성화나 세포내 cAMP 농도 증가는 $LH{\beta}$ subunit mRNA 수준을 증가시키며 이러한 과정은 세포외 $Ca^{++}$ 의존적인 것으로 생각된다. 그러나 PKC 활성화나 cAMP 증가에 의한 세포외 $Ca^{++}$의 역할이 서로 다른 양상을 보인다. PKC 활성화에 의한 LH 분비는 세포외 $Ca^{++}$에 비의존적이나 cAMP에 의해 촉진된 LH 분비는 세포외 $Ca^{++}$ 유입의 영향을 받는 것으로 사료된다.

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Influence of shape and finishing on the corrosion of palladium-based dental alloys

  • Milheiro, Ana;Muris, Joris;Kleverlaan, Cornelis J.;Feilzer, Albert J.
    • The Journal of Advanced Prosthodontics
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    • 제7권1호
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    • pp.56-61
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    • 2015
  • PURPOSE. The purpose of this study was to evaluate the effects of the surface treatment and shape of the dental alloy on the composition of the prosthetic work and its metallic ion release in a corrosive medium after casting. MATERIALS AND METHODS. Orion Argos (Pd-Ag) and Orion Vesta (Pd-Cu) were used to cast two crowns and two disks. One of each was polished while the other was not. Two as-received alloys were also studied making a total of 5 specimens per alloy type. The specimens were submersed for 7 days in a lactic acid/sodium chloride solution (ISO standard 10271) and evaluated for surface structure characterization using SEM/EDAX. The solutions were quantitatively analysed for the presence of metal ions using ICP-MS and the results were statistically analysed with one-way ANOVA and a Tukey post-hoc test. RESULTS. Palladium is released from all specimens studied (range $0.06-7.08{\mu}g{\cdot}cm^{-2}{\cdot}week^{-1}$), with the Pd-Cu alloy releasing the highest amounts. For both types of alloys, ion release of both disk and crown pairs were statistically different from the as-received alloy except for the Pd-Ag polished crown (P>.05). For both alloy type, disk-shaped pairs and unpolished specimens released the highest amounts of Pd ions (range $0.34-7.08{\mu}g{\cdot}cm^{-2}{\cdot}week^{-1}$). Interestingly, in solutions submerged with cast alloys trace amounts of unexpected elements were measured. CONCLUSION. Shape and surface treatment influence ion release from dental alloys; polishing is a determinant factor. The release rate of cast and polished Pd alloys is between $0.06-0.69{\mu}g{\cdot}cm^{-2}{\cdot}week^{-1}$, which is close to or exceeding the EU Nickel Directive 94/27/EC compensated for the molecular mass of Pd ($0.4{\mu}g{\cdot}cm^{-2}{\cdot}week^{-1}$). The composition of the alloy does not represent the element release, therefore we recommend manufacturers to report element release after ISO standard corrosion tests beside the original composition.