• 한국산림과학회지
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• 제109권1호
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• pp.41-49
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• 2020

본 연구는 벌개미취 종자의 대면적 파종 효율성을 증진시키기 위하여, 적절한 종자 전처리 조건과 펠렛코팅 소재를 선정하고자 실시하였다. 벌개미취 종자는 충실종자를 사용하기 위해 1일간 침지처리 후 침강 종자만을 사용하였다. 종자 전처리는 GA₃(200, 500 ppm), 24-epibrassinolide(10^-6, 10^-7, 10^-8 M) 호르몬 처리와 염류삼투프라이밍(100 mM KNO₃) 처리로 구분하였다. 펠렛코팅은 무처리와 프라이밍 처리 종자에 피복물질(DTCS와 DTK)과 접착제(PVA와 CMC)를 적용하여 제작하였다. 종자들은 필터페이퍼, 상토, 사양토 환경에서 파종하여 파종상에 따른 종자 처리 효과를 비교하였다. 필터페이퍼에 파종한 종자의 발아율은 무처리 종자가 41%, 프라이밍 종자가 65%로 가장 높았으며, 호르몬 처리 간 차이는 없었다. 프라이밍과 DTCS/PVA 펠렛 혼용 종자의 발아율은 71%로 가장 높았으며, 프라이밍과 DTK/CMC 펠렛 혼용 종자의 발아율은 42%로 가장 낮았다. 프라이밍 처리 후 펠렛코팅한 종자는 무처리 펠렛코팅 종자보다 발아율, 평균발아일수, 발아속도가 향상되었다. 온실의 상토에 파종한 프라이밍 종자의 발아율은 58%로 가장 높았으며, 평균발아일수는 9.4일, 발아속도는 7.0%·day로 27% 발아율의 무처리 종자보다 높았다. 또한 DTK/PVA 코팅 종자의 발아율(40%)은 무처리 종자의 발아율(27%) 보다 높았으며, 무처리 펠렛코팅한 종자의 평균발아일수는 15.0-27.0일로 프라이밍 처리 후 펠렛코팅한 종자보다 길었다. 온실의 사양토에 파종한 무처리 펠렛코팅 종자와 프라이밍 처리 후 펠렛코팅한 종자의 발아율은 모두 1-39%의 범위로 무처리 종자보다 낮았다. 펠렛 소재인 DTK는 DTCS보다 높은 발아율을 보였으며, 무처리 펠렛코팅 종자의 평균발아일수는 15.0-19.8일로 프라이밍 후 펠렛코팅한 종자보다 느렸다. 본 연구 결과를 기준으로, 벌개미취 종자의 프라이밍 전 처리는 유묘 출현율에 매우 효과적이며, 프라이밍과 펠렛코팅을 병행할 경우, 펠렛 소재로는 DTK가 더 적합하였고, 접착제는 PVA와 CMC 간 차이가 크지 않기 때문에 모두 사용이 가능한 것으로 판단되었다.

• 약학회지
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• 제39권6호
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• pp.593-599
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• 1995

Erythromycin was formulated as enteric-coated pellets in order to reduce degradation in stomach and gastromtestmal irritation, and to maximize the absorption in intestine followmg its oral administration. Core pellets were prepared using fluid-bed granulator with two different methods (powder layering and solvent spraying) and enteric-coated with two different coating polymers (HPMCP and Eudragit E30D). Physical characteristics md dissolution rates of core pellets and enteric-coated pellets were evaluated to optimize the formulation. Powder layering method resulted in shorter initial dissolution time than solvent spraying method, but physicochmical properties of the product were worse than solvent spraying method with respect to hardness, ftiability and density. The dissolution rate of the drug was increased with the addition of surfactants, showing concentration-dependence. The scanning electron microscopic observation of pellets revealed significant differences on the surface appearances prepared with solvent spraying method. The core pellet made with powder layering method had crystals on the surface, which resulted in poor physical properties of the pellets. The dissolution profiles of erythromycin pellets coated with HPMCP or Eudragit L30D were close to that of commercially available erythromycin enteric-coated product.

• 농약과학회지
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• 제2권3호
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• pp.36-44
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• 1998

각기 다른 종류의 입상담체(extruded pellets, sands, zeolites)를 이용하여 보조제의 종류와 조성을 달리하고 주성분을 피복 또는 흡착시켜 제제한 제제품과 조립흡착식으로 제조된 butachlor + chlometholefen(3.5 + 7.0%, 부로트 입제) 혼합입제의 부유성, 수중확산 또는 붕괴성, 수중용출도 및 생물효과를 비교하여 우수한 물성 및 효과를 갖는 용출제어형 입제 제조법을 개발하고자 하였다. 물성이 다른 원제를 이용하여 입제를 제조하기 위해서 여러 제조방식을 이용하는데 원제 2개 이상 혼합된 입제를 제조하기 위해서 고상인 원제와 증량제 및 보조제를 첨가시켜 조립한 뒤 여기에 액상 원제를 흡착시켜 제조한 입제는 우수한 부유성과 수중붕괴성, 안정된 수중용출도를 나타내었으며, 생물효과도 안정적으로 발휘시킬 수 있었다. 기립입자를 담체로 이용하여 피복 또는 흡착시킨 기립피복식 입제들은 부유성, 수중붕괴성 및 생물효과면에서 기존 입제와 대등하거나 우수하였지만 불안정한 수중용출 경향을 나타내었다. 그러나 모래피복형의 경우 기립피복식이나 지오라이트피복식과 달리 액상의 binder가 비교적 안정적으로 주성분들의 수중용출에 도움을 주었고 분상의 dispersing agent보다 액상이 부유성, 수중붕괴성 및 생물효과 면에서 기존과 비슷했거나 좋았던 결과로 볼 때 적절한 binder와 액상의 dispersing agent를 선택하여 제조한다면 기존 조립흡착식 입제와 대등하거나 우수한 물성 및 생물효과를 발현하는 입제를 개발할 수 있는 제조방식인 것으로 판단되었다.

• 대한화학회지
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• 제20권6호
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• pp.486-493
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• 1976

AgI 가루에 PVC를 섞어 Infrared Pellet Presser로 눌러 만든 Pellet을 이용하여 막전극을 만들고 이것을 지시전극으로 사용하여 $Ag^+$의 활동도에 대한 전위를 측정하였다. 이 막전극의 특성을 순수한 AgI pellet와 PVC로 표면을 입힌 AgI pellet을 이용한 두 막전극의 특성과 비교하였다. 이들 막전극의 은이온 활동도에 대한 감응은 은이온의 농도가 $10^{-1}$M에서 $10^{-6}$M 까지의 범위에서 좋은 직선을 보여준다. 그러나 그 중에서도 AgI가루에 PVC를 섞어서 만든 막전극이 Nernstian 기울기에 가장 잘 맞고 견고하고 장시간 사용할 수 있어 가장 우수함을 알 수 있었다. 이 전극은 은이온 이와의 다른 양이온에 대하여는 거의 감응하지 않고 할로겐화이온, 즉$I^-,CI^-,Br^-,CN^-$에 대한 감응도는 $10^{-1}$M에서 $10^{-6}$M까지 직선관계를 유지하였다. 이 전극은 단일 할로겐화이온 뿐 아니라 할로겐화이온의 혼합시료 용액의 전위차 은법적정에 지시전극으로 이용될 수 있음을 알았다.

• 약학회지
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• 제41권1호
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• pp.48-59
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• 1997

Sustained release matrix tablets, pellets, and coated pellets for the delivery of sulindac were prepared using cellulose derivatives at various ratios, and evaluated for the dis solution pattern. The release of sulindac, from matrix tablets prepared with low viscosity HPMC was relatively fast, and especially the tablets made of Metolose SM released all of sulindac within 1 hr. The release of drug from tablets made of other HPMC derivatives were retarded in the order of the following: Pharmacoat 645>Pharmacoat 606>Pharrnacoat 606+HPC-L>HPC-L. The most sustained release pattern was observed with the preparation of high viscous polymer. Metolose 90 SH. While release of sulindac, from matrix type pellet containing 10mg/cap of Metolose 90 SH or 60 SH was completed within 1 hr, a prolonged release formulation (30% in 1 hr) was obtained by the inclusion of EC. Pellets coated with HPMC showed a fast release pattern (${\geq}$ 80% within 2 hrs), whereas pellets coated with HPMC and EC (molar ratio 1 : 1) showed a sustained release pattern (${\geq}$ 80% in 12 hrs), vath the release from EC pellets being the most sustained. Fast (naked) and slow release pellets coated with EC, Metolose 60SH 50cps and propylene glycol. and enteric pellets coated with HPMCP 55 and Myvacet$^{\circledR}$ were prepared, and combined at various ratios for the assessment of dissolution pattern. The result indicates the possibility that the development of 24 hr sustained release delivery systems containing sulindac for oral administration could be achieved by means of combining sustained and fast release pellets at a proper portion.

• 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.

• 한국정밀공학회지
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• 제30권2호
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• pp.223-230
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• 2013

When a new nuclear fuel is developed, an irradiation test needs to be carried out in the research reactor to analyze the performance of the new nuclear fuel. In order to check the performance of a nuclear fuel during the irradiation test in the test loop of a research reactor, sensors need to be attached in and out of the fuel rod and connect them with instrumentation cables to the measuring device located outside of the reactor pool. In particular, to check the temporary temperature change at the center of a nuclear fuel during the irradiation test, a thermocouple should be instrumented at the center of the fuel rod. Therefore, a hole needs to be made at the center of fuel pellet to put in the thermocouple. However, because the hardness and the density of a sintered $UO_2$ pellet are very high, it is difficult to make a small fine hole on a sintered $UO_2$ pellet using a simple drilling machine even though we use a diamond drill bit made by electro deposition. In this study, an automated drilling machine using a CVD diamond drill has been developed to make a fine hole in a fuel pellet without changing tools or breakage of workpiece. A sintered alumina ($Al_2O_3$) block which has a higher hardness than a sintered $UO_2$ pellet is used as a test specimen. Then, it is verified that a precise hole can be drilled off without breakage of the drill bit in a short time.

• Journal of Pharmaceutical Investigation
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• 제38권6호
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• pp.381-385
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• 2008

Isosorbide dinitrate is an oral assiatant therapy agent of angina pectoris, myocardial infarction and congestive heart failure. The objective of this study was to formulate sustained release containing isosorbide dinitrate and assess their formulation variables. Pellets were prepared by fluid bed process and consist of drug layer and membrane layer. The pellets were coated with ethylcellulose along with $5{\sim}15%$ of plasticizer such as triacetin and diethyl butylrate. In vitro evaluation study was performed by comparative dissolution test between test and reference isosorbide dinitrate preparation. We could prepare sustained pellets of isosorbide dinitrate by fluid bed process which were reduced process time and had high content. The pellet coated with 1% ethylcellulose and triacetin(l5%) had a similar dissolution behavior compare to reference isosorbide dinitrate preparation controlling initial dissolution and those of dissolution at 30 min were 17.25 and 17.09%, respectively. Difference factor and similarity factor were $0{\sim}15$ and $50{\sim}100$ and there was no significant difference in bioequivalence between formulations. It might be concluded that our sustained release pellet of isosorbide dinitrate could be an alternatively delivery system to reference drug preparation.

• 대한수의학회지
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• 제48권1호
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• pp.27-32
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• 2008

The present study was carried out to develop a sustained release implantable formula of bovine somatotropin (SRIF-BST) and to examine its sustained release effect. The SRIF-BST was produced by coating a solid pellet, which was comprised of BST and an excipient, made of a biodegradable polymer and poloxamer, which are capable of regulating the rate of BST release. The coated membrane of SRIFBST was observed with a field emission scanning electron microscope. The thickness of the coated membrane was approximately $1{\mu}m$, and the pore sizes of the coated membrane surface were below $10{\mu}m$. In dissolution test, the release duration of the SRIF-BST maintained for 10 days, whereas the release duration of the control BST formula maintained for 3 days. In weight gain assay and tibia test of hypophysectomized rats, the release duration of the SRIF-BST treated group was 12 days and the net weight gain was 53.16 g, also the tibia length and strength of the SRIF-BST treated group was increased 10.5% and 23.1% compared with those of the control group, respectively.

• Environmental Engineering Research
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• 제19권1호
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• pp.37-40
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• 2014

This research investigates the quality changes during composting of bagasse and pig manure amended with 30% of surfactant-coated charcoal (SC). Two treatments, 30% uncoated charcoal (UC) amendment and no charcoal (NC) amendment, were done as control. Charcoal was coated with 0.37 mM tetradecyltrimethylammonium bromide (TDMA), a cationic surfactant, at the dosage of 10 g/L. At the end of the composting period, the carbon to nitrogen (C/N) ratio of SC amendment was 9.7; whereas, the C/N ratios of UC and NC amendment were 12.6 and 21.4, respectively. Plant nutrients contents of the compost produced from SC amendment were 20.7 mg $NH_4{^+}-N/g$, 42.8 mg $NO_3{^-}-N/g$, and 41.7 mg P/g. High nitrate and phosphate concentrations in SC amendment were due to the adsorption of these anions on the positive charge of TDMA. Desorption of plant nutrients retained in the compost pellets was also investigated. It was predicted that nitrate was fully desorbed from a pellet at 23 days for SC amendment, which was later than UC (14 days) and NC (10 days) amendment. A slow release of nitrate from the compost pellet will reduce the nitrate leaching into the environment. Thus, the adding of SC in the compost pile is one of the alternative methods to improve the quality of compost and plant nutrient retention.