• 한국식품영양과학회지
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• 제37권12호
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• pp.1684-1687
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• 2008

보리를 침맥한 후 5일 동안 발아하는 제맥과정 중에 arabinoxylan 함량의 변화를 측정하였다. 제맥과정 중 초기에 불용성인 보리의 arabinoxylan은 발아과정 중에 가용화됨에 따라 수용성 arabinoxylan의 함량이 약간 증가하는 추세를 보여주었다. 발아중인 보리의 수용성 arabinoxylan 부분은 $21^{\circ}C$ 추출온도에 비해 $45^{\circ}C$의 추출온도에서 보다 높은 함량 으로 나타났다. 발아시간에 따라 적절히 변형된 맥아(96시간 발아)와 덜 변형된 맥아(60시간 발아)를 선발하여 변형정도 에 따른 두 가지 맥아에 대하여 당화온도별로($45{\sim}75^{\circ}C$) 당 화 후 맥즙의 arabinoxylan 함량을 분석하였다. 당화온도를 $45^{\circ}C$에서 $75^{\circ}C$를 증가시킴에 따라 맥즙에 용출되어져 나오는 arabinoxylan의 함량은 약간 감소하는 경향을 보였다. 본 실험의 당화조건에서 적절히 변형된 맥아로부터 얻은 맥즙과 덜 변형된 맥아로부터 얻은 맥즙 간의 arabinoxylan 함량에서 큰 차이를 나타내지 않았다.

• Journal of Pharmaceutical Investigation
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• 제6권3호
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• pp.58-69
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• 1976

It is well established that dissolution is freruently the rate limiting step in the gastrointestinal absorpton of a drug from a solid dosage from. The relationship between the dissolution rate and absorption is particularly distinct when considering drugs of low solubility. Consequently, numerous attempts have been made to modify the dissolution characteristics of poorly water soluble drugs. Since dissolution rate is directly proportional to surface area, one may increase the rate by decreasing the particle size of the drug. Levy has considered a number of methods by which a drug may be presented to the GI fludids in finely divided from. The direct method is the utilization of microcrystalline or micronized particles. A second method involves the administration of solutions from which, upon dilution with gastric fluids, the dissolved drug will precipitate in the form of very fine particles. A more unique way of obtaining microcrystalline dispersions of a drug has been ercently suggested by Sekiguchi et al. They have first proposed the formation of a eutectic mixture of a poorly water soruble drug with a physiologically inert, easily soluble carrier. When such systems are exposed to water or GI fluids, the soluble carrier will dissolve rapidly and the finely dispersed drug particles will then be released. It has been suggested by Shefter and Higuchi that the formation of crystalline solvate could be a powerful tool in affecting rapid disslution of highly insoluble substances. Goldberg et al. have noted that the formation of solid solution could reduce the particle size to a minimum and increase the dissolution rate as well as the solubility of the durgs. It has also been shown that the rates of solution of drugs were appreciably increased by coprectipitating the drug with soluble polymers. The increase was found to be sensitive to the method of preparation, the molecular weight of polymer and the particular ratio of drugs to polymer. Although several investigations have demontrated that the solubility and/or dissolution rates of drugs can be increased in this manner, little information is available in the literature related to the in vivo absorption pattern of drugs orally administered as PVP coprecipitates. Recently, however, it was demonstrated that both the rate and extent of absorption of the insoluble drug could be markedly enhanced when orally administered to rats in the form of a coprecipitate with PVP. The purpose of the present investigation was to ascertain the general appility of soluble polymer coprectation technique as a method for enhancing the in vitro dissolution rate of hydrophobic indomethacin. To accomplish this aim, the dissolution characteristics of pure indomethacin, indomethcin-polymer physical mixtures and indomethacin-polymer coprecipitates were quantitatively studied by comparing their relative dissolution rates. The solubility and dissolution behavior of these systems were also examined.

• 약학회지
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• 제28권3호
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• pp.161-167
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• 1984

To improve the solubility properties of indomethacin, a poorly water-soluble drug, some attempts were made with surfactants, such as sodium deoxycholate, sodium laurylsulfate and polysorbate-80. The enhancement effect in solubility was found to be due to the micellar solubilization and dependent on the concentration of surfactants, pH and temperature. The mechanism of interaction was suggested to be attributed to the formation of mixed micelles between the drug and solubilizers.

• Animal cells and systems
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• 제10권4호
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• pp.237-241
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• 2006

Chemotactic behavior is essential for the survival of animals. However, the mechanism by which animals carry out chemotaxis is poorly understood. To explore the biochemical events underlying chemotaxis, we isolated C. elegans mutants that displayed abnormal chemotactic responses to cAMP, a strong attractant for C. elegans. Based on their responses to other chemoattractants, the mutant animals could be classified into five groups: (1) animals with defective chemotaxis to cAMP only; (2) animals with defective chemotaxis to both cAMP and cGMP; (3) animals with defective chemotaxis to water-soluble attractants; (4) animals with defective chemotaxis to both water-soluble and volatile attractants; and (5) animals with enhanced chemotactic responses. We expect that analyses of these mutants will help understand the molecular mechanisms underlying chemotaxis in C. elegans.

• Journal of Pharmaceutical Investigation
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• 제41권4호
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• pp.239-247
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• 2011

Simvastatin is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which catalyzes the conversion of HMG-CoA to mevalonate, an early and rate-limiting step in the biosynthesis of cholesterol. Simvastatin has good permeability, but it also has low solubility (BCS class II), which reduces its bioavailability. To overcome this problem, a solid dispersion is formed using a spray-dryer with polymeric material carrier to potentially enhance the dissolution rate and extend drug absorption. As carriers for solid dispersion, Gelucire$^{(R)}$44/14 and Gelucire$^{(R)}$ 50/13 are semisolid excipients that greatly improve the bioavailability of poorly-soluble drugs. To avoid any toxic effects of an organic solvent, we used aqueous medium to melt Tween$^{(R)}$ 80 and distilled water. The structural behaviors of the raw materials and the solid dispersion were analyzed by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). The DSC and PXRD data indicated that the crystalline structure of simvastatin was transformed to an amorphous structure through solid dispersion. Then, solid dispersion-based tablets containing 20 mg simvastatin were prepared with excipients. Dissolution tests were performed in distilled water and artificial intestinal fluid using the USP paddle II method. Compared with that of the commercial tablet (Zocor$^{(R)}$ 20 mg), the release of simvastatin from solid dispersion based-tablet was more efficient. Although the stability study is not complete, this solid dispersion system is expected to deliver poorly water-soluble drugs with enhanced bioavailability and less toxicity.

• 대한화장품학회지
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• 제41권3호
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• pp.201-208
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• 2015

오가노겔은 반고형상이며 3차원의 네트워크 구조로 이루어진 친유성 용매로 이루어져 있다. 본 연구에서는 유상과 수상에서 모두 난용성 특징을 가진 제니스테인을 포함하는 레시틴 오가노겔을 개발하였다. 이 시스템은 안정할 뿐만 아니라 경피 흡수 실험에서도 높은 흡수율을 보였다. 본 오가노겔 제형에 적합한 원료들을 선별한 결과, 수화된 레시틴, 해바라기유, dipropylene glycol (DPG), polyethylene glycol (PEG)이 이 시스템에서 주로 사용되었다. 레시틴 오가노겔의 제조에 적합한 원료의 함량은 phase ternary diagram 작성을 통하여 결정하였다. 제조된 레시틴 오가노겔을 organoleptic characteristics, stability, pH, rheology, phase transition temperatures, microscopic analysis, skin penetration 실험을 통해 평가하였다. 본 연구 결과를 통해 본 논문에서 제시하는 레시틴 오가노겔 제형은 안정한 상태에서 난용성 물질을 높은 농도로 피부에 효과적으로 전달할 수 있는 제형으로 활용될 수 있을 것이라 생각된다.

• 청정기술
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• 제16권2호
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• pp.80-87
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• 2010

본 연구에서는 초음파가 결합된 초임계유체 입자 제조 기술인 SAS-EM 공정을 이용하여 난용성 항진균제인 이트라코나졸의 미세입자를 제조하였다. 실험에 사용된 SAS-EM 장치의 경우 초음파가 분사노즐에 직접 적용되었다는 점에서 기존의 SAS-EM 공정과 차이가 있으며, 초음파 세기, 공정온도, 용매 등의 여러 공정변수가 미세입자 형성에 미치는 영향을 고찰하였다. 초음파의 세기가 증가할수록 더 작은 크기를 가지는 입자의 생성률이 증가하였으며, SAS-EM 공정으로 제조된 미세입자도 원시료와 마찬가지로 결정구조를 가짐을 확인하였다. 초음파의 영향을 고찰하기 위해 기존의 초임계 ASES 공정과 비교하였으며, SAS-EM 공정에 의해 크기가 더 작은 입자가 형성됨을 확인하였다.

• 한국식품과학회지
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• 제40권3호
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• pp.360-363
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• 2008

발아시간에 따라 덜 변형된 맥아(60시간 발아)와 적절히 변형된 맥아(96시간 발아)의 총, 불용성 및 수용성 ${\beta}-glucan$ 함량을 측정하였다. 보리의 총 ${\beta}-glucan$ 함량은 3.96%였으며 발아 중에 감소하였는데 덜 변형된 맥아에서는 1.02%인 반면에 적절히 변형된 맥아에서는 0.18%로 급격히 감소하였다. 적절히 변형된 맥아는 $21^{\circ}C$와 $45^{\circ}C$ 추출온도에서 ${\beta}-glucan$ 용해성이 덜 변형된 맥아에 비해 현저하게 증가하였다. 변형정도가 다른 두가지 맥아에 대하여 당화온도별로 당화 후 맥즙과 맥주의 점도를 분석하였다. 당화온도가 $45-75^{\circ}C$로 증가함에 따라 맥즙과 맥주의 점도가 증가하였으며 적절히 변형된 맥아가 덜 변형된 맥아에 비해 점도의 상승이 크지 않았다. 이는 적절히 변형된 맥아는 덜 변형된 맥아에 비해서 당화과정중에 ${\beta}-glucan$ 용해성이 상대적으로 높지만 초기 ${\beta}-glucan$의 함량이 낮을 뿐 만 아니라 맥아에 충분히 합성되어 발달된 ${\beta}-glucanse$의 활성에 의해 당화과정 중에 용출되어지는 ${\beta}-glucan$의 분해가 이루어지기 때문인 것으로 판단되었다.

• Journal of Pharmaceutical Investigation
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• 제38권2호
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• pp.111-117
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• 2008

To overcome the solubility of poorly water-soluble drug, the formation of solid dispersion using a spray-dryer with polymeric material, that can potentially enhance the dissolution rate extend of drug absorption was considered in this study. $Eudragit^{(R)}$ E100 as carrier for solid dispersion is acrylate copolymer that soluble in acidic buffer solutions (below pH 5.0). It was used to increase dissolution of atorvastatin calcium as a water-insoluble drug in acidic environments. In this study, a spray-dryer was used to prepare solid dispersion of atorvastatin calcium and $Eudragit^{(R)}$ E100 for purpose of improving the solubility of drug. Atorvastatin calcium and $Eudragit^{(R)}$ E100 were dissolved in ethanol and spray-dryed. DSC and XRD were used to analyze the crystallinity of the sample. It was found that atorvastatin calcium is amorphous in the $Eudragit^{(R)}$ E100 solid dispersion. FT-IR was used to analyze the salt formation by interaction between atorvastatin calcium and $Eudragit^{(R)}$ E100. Comparative dissolution study exhibited better dissolution characteristics than the commercial drug ($Lipitor^{(R)}$) as control. The dissolution rate of atorvastatin calcium was markedly increased in solid dispersion system in simulated gastric juice (pH 1.2). This study proposed that this solid dispersion system improved the bioavailability of poorly water-soluble atorvastatin calcium.

• Journal of Pharmaceutical Investigation
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• 제20권1호
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• pp.13-18
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• 1990

Hydrocortisone (HC) sustained-release suppositories were prepared by using a solid matrix of methacrylic acid-methacrylic acid methyl ester copolymer $(Eudragit\;L_{100}^{R}:\;EL)$ as a poorly water soluble carrier and polyethylene glycole 1540 (PEG) as an water soluble carrier. HC release rate was controlled by complexation with ${\beta}-cyclodextrin$ $({\beta}-CyD)$ which was confirmed by X-ray diffractometry, IR-spectroscopy and differential scanning calorimetry. Release rate of HC from the EL-PEG matrix suppositories decreased with increase of EL contents. The release rale from $HC-{\beta}-CyD$ complex decreased in the following order: $HC-{\beta}-CyD/PEG$ > HC/PEG > $HC-{\beta}-CyD/EL_{10%}-PEG$ > $HC/EL_{10%}-PEG$ > $HC-{\beta}-CyD/EL_{15%}-PEG$ > $HC/EL_{15%}-PEG$ > $HC-{\beta}-CyD/EL_{20%}-PEG$ > $HC/EL_{20%}-PEG$. The crystallinity of HC in polymer matrix was identified using X-ray diffractometer and the surface of matrix suppositories after release test was examined by scanning electron microscopy. The sustained release of HC from these matrix suppositories was attributed to the network structure of EL.