• Journal of Pharmaceutical Investigation
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• 제24권2호
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• pp.57-65
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• 1994

To increase the dissolution rate of practically insoluble biphenyl dimethyl dicarboxylate (DDB), various solid dispersions were prepared with water soluble carriers, such as povidone (PVP K-30), poloxamer 407, sodium deoxycholate (SDC) and polyethylene glycol (PEG) 6000, at drug to carrier ratios of 1:3, 1:5 and 1:10 (w/w) by solvent or fusion method. Dissolution test was performed by the paddle method. The dissolution rate of DDB tablets (25 mg) on market was found to be very low (11.44, 9.02 and 6.42% at pH 1.2, 4.0 and 6.5 after 120 min, respectively). However, dissolution rates of DDB from various solid dispersions were very fast and reached supersaturation within 10 min. DDB-PEG 6000 solid dispersion appeared to be better in enhancing the in vitro dissolution rate than others. Furthermore, the incorporation of DDB and phosphatidylcholine (PC) into ${\beta}-cyclodextrin$ at ratios of 1:2:20, 1:5:20 and 1:10:20 resulted in a 4.9-, 11.2- and 19.6-fold increase in DDB dissolution after 120 min as compared with the pure drug, respectively. This might be attributed to the formation of lipid vesicles which entrapped a certain concentration of DDB during dissolution. On the other hand, the permeation of DDB through rabbit duodenal mucosa was examined using some enhancers such as SDC, sod. glycocholate (SGC) and glycyrrhizic acid ammonium salt (GAA). Only trace amounts of DDB were found to permeate through deuodenal mucosa in the absence of enhancer. SDC was found to markedly decrease the permeation flux of DDB, however, SGC and GAA (5 mM) enhanced the flux of DDB 1.6 and 2.4 times higher as compared with no additive, respectively.

• Mass Spectrometry Letters
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• 제7권3호
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• pp.79-83
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• 2016

We prepared solid dispersion formulations of quercetin to enhance its solubility and dissolution rate. Various quercetin-loaded solid dispersion were tested with quercetin, poloxamer 407, and carrier such as hydroxypropyl methyl cellulose (HPMC), polyethylene glycol 8000 (PEG 8000), and polyvinylpyrrolidone K40 (PVP K40) using solvent evaporation and freeze drying methods in terms of both the aqueous solubility and the dissolution rates of quercetin. The solubility of quercetin as its solid dispersion formulations was markedly improved compared with that of quercetin powder. Especially, highest solubility of quercetin was observed when HPMC was used as a carrier. The cumulative dissolution of quercetin within 360 min from solid dispersion composed of quercetin, poloxamer 407, and HPMC was 8.8-fold higher than the dissolution of pure quercetin. The results of powder X-ray diffraction (XRD) and scanning electron microscope (SEM) indicated that quercetin transformed from a crystalline to an amorphous form through the solid dispersion formulation process. These results suggest that the solid dispersion formulation of quercetin with poloxamer 407 and HPMC could be a promising option for enhancing the solubility and dissolution rate of quercetin.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 추계 총회 및 학술발표회
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• pp.87-90
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• 1998

1. 서론 : 막 분리공정에 사용되고 있는 대부분의 고분자 막들은 침지침강(immersion precipitation) 상변환법에 의해 제조되고 있다. 침지침강 상변환법으로 제조된 막의 최종 구조는 고분자 캐스팅 용액의 열역학적 특성과 비용매와의 속도론적 특성에 따라 대칭형 또는 비대칭형 막구조를 갖게 된다. 고분자/용매로 이루어진 캐스팅 용액에 제3의 성분으로서 PVP, PEG, LiCl. ZnCl$_2$ 와 같은 유.무기물을 첨가시킴으로서 막구조 및 투과성능을 변화시킬 수 있다. 이러한 점에서 이들 첨가제를 pore-forming agent라 부르기도 한다. 본 연구에서는 상대적으로 열적.기계적 특성이 우수하고, 화학약품에 대한 안정성이 뛰어나 상변환 막의 소재물질로서 널리 사용되고 있는 Polyethersulfone(PES)을 막 소재 물질로 사용하여 PES/NMP 캐스팅 용액에 다양한 종류의 무기염[CaCl$_2$, LiCl, LiClO$_4$, Mg(ClO$_4)_2$, ZnCl$_2$]을 PES에 대한 중량비를 달리하여 첨가시켜 비대칭 막을 제조하여 무기염의 첨가가 막구조 형성 및 막투과 특성에 미치는 영향을 연구하였다. 이때 첨가된 무기염 및 첨가 중량비에 따른 영향을 PES/NMP/Salt 계의 coagulation value, light transmittance, 점도 등의 열역학 및 속도론적 특성으로서 설명하였다.

• Journal of Pharmaceutical Investigation
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• 제32권3호
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• pp.191-197
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• 2002

Polymer based physical mixtures or solid dispersions containing solubilizing compositions[OA, tween80 and SLS] were prepared using a spray-dryer. Lovastatin(LOS), simvastatin(SIMS), aceclofenac(AFC) and cisapride(CSP) were selected as poorly water-soluble drugs. Dextrin, poly(vinylalcohol) (PVA), poly(vinylpyrrolidone)(PVP) and polyethylene glycol(PEG) were chosen as solubilizing carriers for solid dispersions. The solid dispersions containing solubilizing compositions without drug were prepared without using organic solvents or tedious changes of formulation compositions. This system could be used to quickly screen the dissolution profiles of poorly water-soluble drugs by simply mixing with drugs thereafter. In case of solid dispersion containing drug, organic solvent systems could be used to solubilize model drugs. The dissolution rates of the drugs were higher when mixed with drug and solid dispersions containing solubilizing compositions. However, solid dispersions of LOS, AFC, and CSP simultaneously containing drug and solubilizing compositions in organic solvent systems were more useful than physical mixtures of drug and solid dispersions without drug except SIMS. Based on solubilizing capability of polymer based physical mixtures in gelatin hard capsules, optimal solid dispersion system of poorly water-soluble drugs could be formulated. However, it should be noted that dissolution rate of poorly water-soluble drugs were highly dependent on drug properties, solubilizing compositions and polymeric carriers.

• Membrane and Water Treatment
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• 제2권1호
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• pp.25-37
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• 2011

PES UF membranes containing silver were prepared to impart antibacterial properties for waste water treatment. Asymmetric membranes for antibacterial application were prepared from polyethersulfone (PES) and silver nitrate ($AgNO_3$) (PES/$AgNO_3$=15/2 by weight) solution in N-Methyl-2-pyrrolidone (NMP) via simple wet phase inversion technique. These membranes were characterized by polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) of different molecular weights (1000 ppm in water) at room temperature and on operating pressure of 5 bars. It was observed that the water flux of PES-$AgNO_3$ membrane is slightly lower than virgin PES but still increased linearly with the increment of pressure applied. The morphology of the resulting membranes was examined using Field-Emission Scanning Electron Microscope (FESEM) coupled with Energy Dispersive Spectroscopy (EDS). Elemental analysis using EDS proved that silver is successfully loaded on the membrane surfaces. Due to the success of loading silver on membrane surfaces, antibacterial activities were evaluated via agar diffusion method against Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus) culture. By incorporating 2 wt% of silver nitrate, PES-$AgNO_3$ showed significant inhibition ring on both E.coli and S.aureus. Filtration of E.coli solution (OD 0.31) showed satisfactory rejection data with ~100% inhibition growth after 24 hours incubation at $37^{\circ}C$. Resultant membranes also exhibit better tensile strength (compared to virgin PES) up to 71% may be due to the suggested interactions. The residual silver during fabrication was measured using ICP-MS and result showed that the residual silver content of PES-$AgNO_3$ membrane was only ~1% of the original silver added in the polymer solution. These studies have shown that PES-$AgNO_3$ UF membranes are potential in improving the filtration in water treatment.

• 약학회지
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• 제38권3호
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• pp.250-264
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• 1994

Omeprazole(OMZ)-cholestyramine(CHL) and various OMZ-Dowex resin complexes were prepared by reaction between OMZ and activated resins in 0.1N NaOH solution. And their physical properties were tested by means of infrared(IR), differential scaning caloimeter(DSC), X-ray diffraction. Chemical stability of OMZ-CHL was increased markedly compared with OMZ and the decomposition of OMZ-CHL followed the pseudo first-order kinetics and the rate constants were $2.743{\times}10^{-4}/day$ at $20^{\circ}C$, $7.83{\times}10^{-3}day^{-1}$ under 80% RH and $1.68{\times}10^{-2}day^{-1}$ under UV radiation, respectively. On the other hand, the rate constants of OMZ were $2.996{\times}10^{-4}day^{-1}$ at $20^{\circ}C$, $1.17{\times}10^{-2}day^{-1}$ under 85% RH, and $4.07{\times}10^{-2}day^{-1}$ under UV radiation, respectively. The rates of dissolution of OMZ-CHL bulk and OMZ-CHL tablet were 100% and more than 85% in 15 minutes, respectively, which were increased than OMZ base and OMZ-tablet. In the acute toxicological test, the value of oral $LD_{50}$(mouse) was 4.608 g/kg. OMZ-CHL was pelletized using lactose, polyethyle neglycol(PEG), D-sorbitol, Avicel PH 101, sodium laurylsulfate and polyvinylpyrrolidone(PVP) K-30, and enteric coated with HPMCP, Myvacet, acetone, ethanol and cetanol, of which dissolution rate was found to be more than 85% in 10 minutes. From the above results, it was found that OMZ-CHL is a useful means for development of new oral dosage forms of OMZ.

• 한국버섯학회지
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• 제5권1호
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• pp.39-42
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• 2007

색소변이체에서 버섯 바이러스의 게놈인 dsRNA가 확인되었으며, 크기는 각각 5.8kb, 1.8kb 이었다. 느타리바이러스 진단용 프라이머인 PVP로 RT-PCR을 수행한 결과 500bp 크기의 특이밴드가 관찰되었다. 또한 양송이 바이러스 진단용 프라이머 LIVP와 MBVP에서도 특이밴드가 관찰되었으나 양송이 바이러스와는 다른 양상이었다. 원형느타리의 백색변이체 (MGL2205)에 존재하는 바이러스유사입자는 구형이었으며, 크기는 14, 20~45nm이었다. 균사체의 세포단면을 관찰한 결과 바이러스 순화액에서 확인된 바이러스유사입자와 비슷한 구형의 입자들이 관찰되었으며, 순화된 바이러스와 동일한 입자인지는 추후 확인되어야 할 것으로 사료된다. 원형느타리 백색변이체(MGL2205)에 존재하는 바이러스의 최적 증식 조건은 $15^{\circ}C$, pH 6, 배양기간 3주인 것으로 판단되며, 이 결과는 이와 유사한 재배적 조건에서 재확인되어야 할 것으로 사료된다.

• 한국식품과학회지
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• 제22권6호
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• pp.611-617
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• 1990

Vitamin $B_{12}$의 생산성을 높이기 위하여 Bacillus natto와 vitamin $B_{12}$ 생산균주로 알려진 Bacillus megaterium IAM 1166 균주간의 종간 원형질체 융합을 시도하였다. 변이원 처리에 의해 활성이 우수하며 genetic marker로써 $thr^-try^-rif^r$인 Bacillus natto SH-34 및 $arg^-ade^-lys ^-str^r$의 genetic marker를 가진 Bacillus megaterium BK-13을 분리하였다. 원형질체 융합을 행하기 위하여 $500\;{\mu}g/ml$ lysozyme 처리시 원형질체 형성률과 재생률은 99% 및 67%를 나타내었다. 변이주 Bacillus natto SH-34 및 Bacillus megaterium BK-13간에 $1.0{\times}10^{-5}$을 나타내었다. 융합주 MNF-72는 vitamin $B_{12}$ 생산용 배지에서 $7.85\;{\mu}g/ml$의 높은 생산성을 나타내었으며, 융합주 MNF-72를 sodium alginate로 고정화를 하여 회분식 및 연속식 발효를 행하였을 때 72시간에 $0.58\;{\mu}g/ml.hr$ 및 $0.80\;{\mu}g/ml.hr$의 vitamin $B_{12}$를 생산하였다.