• 공업화학
• /
• 제24권2호
• /
• pp.190-195
• /
• 2013

이전 연구에서 저자들은 사자발쑥 추출물의 항산화, 항노화 및 항균활성에 대한 결과를 보고한 바 있다. 본 연구에서는 사자발쑥 추출물의 피부 전달시스템으로 에토좀을 제조하고 입자크기, 포집효율 및 피부 투과를 평가하였다. 0.06% 사자발쑥 추출물의 에틸아세테이트 분획을 담지한 에토좀은 3주 동안 보다 더 안정하였고 일정한 입자크기를 유지하였다. 0.06% 에틸아세테이트 분획을 함유한 에토좀의 입자 크기는 $287.05{\pm}0.25nm$, 포집효율은 $51.96{\pm}0.01%$였다. 피부 투과 실험 결과, 에토좀 제형은 일반 리포좀이나 20% 에탄올 용액에서 보다 큰 피부 투과능을 보여주었다.

• 한국응용과학기술학회지
• /
• 제31권3호
• /
• pp.367-374
• /
• 2014

In this study, skin permeation enhancement was confirmed by designing it to have a structure and composition similarity to the intercellular lipids that improve miscibility with skin by cross-linked lipids poloxamer. The cross-linked lipids poloxamer was synthesized and analyzed by 1H NMR that structure dose had conjugated pluronic with ceramide3. Active component is released by modification of liquid crystal structure because PPO part, large-scale molecule block of pluronic, has hydrophobic nature at skin temperature of $35^{\circ}C$. Conjugated pluronic with ceramide3 was synthesized using Pluronic F127 and p-NPC (4-nitrophenyl chloroformate) at room temperature yielded 89%. Pluronic(Ceramide 3-conjugated Pluronic) was synthesized by reaction of p-NP-Pluronic with Ceramide3 and DMAP. The yield was 51%. This cross-linked lipids poloxamer was blended and dissolved at isotropic state with skin surface lipids, phospholipid, ceramide, cholesterol and anhydrous additive solvent. Next step was preceded by ${\alpha}$-Transition at low temperature for making the structure of Meso-Phase Lamella, and non-hydrous skin analogue liquid crystal using thermo-sensitivity smart sensor, lamellar liquid crystal structure through aging time. For confirmation of conjugation thermo-sensitivity smart sensor and non-hydrous skin analogue liquid crystal, structural observation and stability test were performed using XRD(Xray Diffraction), DSC(Differential Scanning Calorimetry), PM (Polarized Microscope) And C-SEM (Cryo-Scanning Electron Microscope). Thermo-sensitivity observation by Franz cell revealed that synthesized smart sensor shown skin permeation effect over 75% than normal liquid crystal. Furthermore, normal non-hydrous skin analogue liquid crystal that not applied smart sensor shown similar results below $35^{\circ}C$ of skin temperature, but its effects has increased more than 30% above $35^{\circ}C$.

• Journal of Pharmaceutical Investigation
• /
• 제38권6호
• /
• pp.373-380
• /
• 2008

In order to develop optimal formulation and iontophoresis condition for the transdermal delivery of levodopa, we have evaluated the effect of two permeation enhancers, ethanol and oleic acid in microemulsion, on transdermal delivery of levodopa. In vitro flux studies were performed at $33^{\circ}C$, using side-by-side diffusion cell and full thickness hairless mouse skin. Current density applied was $0.4\;mA/cm^2$ and current was off after 6 hours application. Levodopa was analysed by HPLC at 280 nm. The o/w microemulsions of oleic acid in buffer solution (pH 2.5 & 4.5) were prepared using oleic acid, Tween 80 and ethanol. The existence of microemulsion regions were investigated in pseudo-ternary phase diagrams. Contrary to our expectation, cumulative amount of levodopa transported from microemulsion (pH 2.5) for 10 hours was similar to that from aqueous solution in all delivery methods (passive, anodal and cathodal). When pH of the micro-emulsion was pH 4.5, cumulative amount of levodopa transported for 10 hours increased about 40% (anodal) to 50% (cathodal), when compared to that from aqueous solution. Flux from pH 4.5 microemulsion showed higher value than that from pH 2.5 in all delivery methods. These results seem to indicate that electroosmosis plays more dominant role than electrorepulsion in the flux of levodopa at pH 2.5. The effect of ethanol on iontophoretic flux was studied using pH 2.5 phosphate buffer solution containing 3% or 5% (v/v) ethanol. Flux enhancement was observed in passive and anodal delivery as the concentration of the ethanol increased. Without ethanol, cathodal delivery showed higher flux than anodal delivery. Anodal delivery increased the cumulative amount of levodopa transported 1.6 fold by 5% ethanol after 10 hours. However, in cathodal delivery, no flux enhancement of levodopa was observed during current application and only marginal increase in cumulative amount transported after 10 hours was observed by 5% ethanol. These results seem to be related to the decrease in dielectric constant of the medium and the lipid extraction of the ethanol, which decrease the electroosmotic flow, and thus decrease the flux. Overall, the results provide important insights into the role of electroosmosis and electrorepulsion in the transport of levodopa through skin, and provide some useful informations for optimal formulation for levodopa.

• Journal of Pharmaceutical Investigation
• /
• 제29권3호
• /
• pp.227-234
• /
• 1999

Solid dispersions were prepared to increase the dissolution rate of biphenyl dimethyl dicarboxylate (DDB) using water-soluble carriers such as povidone, copolyvidone, $2-hydroxypropyl-{\beta}-cyclodextrin (HPCD)$, sodium salicylate or sodium benzoate by solvent evaporation method. Solid dispersions were characterized by infrared spectrometry, differential scanning calorimetry (DSC) and powder X-ray diffractometry, dissolution and permeation studies. DDB tablets (7.5 mg) were prepared by compressing the powder mixtures composed of solid dispersions, lactose, com starch, crospovidone and magnesium stearate using a single-punch press. DDB capsules (7.5 mg) were also prepared by filling the mixtures in empty hard gelatin capsules (size No.1). From the DSC and powder x-ray diffractometric studies, it was found that DDB was amorphous in the HPCD or copolyvidone solid dispersions. Dissolution rates after 10 min of DDB alone and solid dispersions (1 : 10) in sodium benzoate, sodium salicylate and copolyvidone were 11.8, 23.5, 22.8 and 82.5%, respectively. Dissolution rates of DDB after 30 min from 1 : 10 and 1 : 20 copolyvidone solid dispersions were 80.5 and 95.0%, respectively. For the DDB tablets prepared using solid dispersions (1 : 20), the initial dissolution rate was dependent on carrier material, and was ranked in order, $Kollidon\;30\;{\ll}$ copolyvidone < HPCD. For the HPCD solid dispersion tablets, dissolution rate reached 97.4% after 15 min, but thereafter slowly decreased to 80.7% after 2 hr due to the precipitation of DDB. However, in the case of copolyvidone solid dispersion tablets, dissolution increased linearly and reached 93.4% after 2 hr. Reducing the volume of test medium from 900 to 300 ml markedly decreased the dissolution rate of the tablets containing 1 : 20 HPCD solid dispersions and 1 : 10 copolyvidone solid dispersion. For 1 : 20 copolyvidone solid dispersion tablets, there was no significant change in dissolution rate up to 1 hr with different volumes of test medium. Preparation of the copolyvidone solid dispersion (1 : 20) in capsules markedly delayed the dissolution (31.2 % after 2hr) due to the limited diffusion within capsules. The permeation rate $(13.4\;g/cm^2\;after\;8\;hr)$ of DDB through rabbit duodenal mucosa from copolyvidone solid dispersion (1 : 10) was markedly enhanced, when compared with drug alone or physical mixtures. From overall findings, DDB formulations containing copolyvidone solid dispersions (1 : 20) could be used to remarkably improve the dissolution rate in dosage form of powders and tablets.

• Bulletin of the Korean Chemical Society
• /
• 제35권11호
• /
• pp.3188-3194
• /
• 2014

Compound K (CK) was formulated as polymeric micelles (PM) using Pluronic$^{(R)}$ F-127 to enhance the oral absorption of CK, an intestinal bacterial metabolite of ginseng protopanaxadiol saponin. The physicochemical properties of Ck-loaded PM were characterized and an in vitro transport study using the Caco-2 cell system as well as an in vivo pharmacokinetic study using SD rats was carried out. The hydrodynamic mean particle size of CK-loaded PM (CK-PM) was $254{\pm}23.45nm$ after rehydration and the drug loading efficiency was ca. 99.9%. The FT-IR spectroscopy, X-ray diffraction, differential scanning calorimetry and scanning electron microscopy data supported the presence of a new solid phase in the PM. The $P_{app}$ value of in vitro Caco-2 cell permeation of CK-PM and the oral absorption of CK was enhanced about 1.2-fold and 2.6-fold compared to CK suspension, respectively, showing that the present PM formulation enabled an enhancement of oral CK absorption.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2018년도 추계학술대회
• /
• pp.497-498
• /
• 2018

화재 현장은 정전과 연기와 유독가스로 인해 열영상카메라 및 제논탐조등으로도 전방 가시거리 1m를 확보하기 힘든 것이 현실이다. 화재현장의 연기입자를 분석해보면, 파장 $5{\mu}m$ 이하의 흰색 연기일지라도, 가시거리가 1미터 이상이 되면 기존의 열영상 카메라 등을 이용할 경우 전방시야 확보가 어렵다. 입자 파장 $5{\mu}m$ 이상의 검은 연기에는 화학소재와 가스, 물분자가 섞여 있어 단일 센서가 아닌 다양한 센서를 이용한 공간투과 센서 기술이 필요하다. 전방 안전시야 확보를 위해 연기투과 및 공간정보 가시화를 위한 라이다 센싱 기술이 필요하다. 본 논문에서는 32bit CPU코어 및 주변회로를 갖춘 정보처리 시스템의 인터페이스를 설계하였다. 또한 라이다 센서와의 인터페이스를 구현하고 이를 시뮬레이션 하였으며 이를 통해 향후 휴먼 증강 소방헬멧의 정보처리 시스템을 구현 가능한 인터페이스를 제공하였다.

• Archives of Pharmacal Research
• /
• 제17권2호
• /
• pp.57-59
• /
• 1994

The effect of sodium taurodihydrofusidate (STDHF) on drug permeation across nasal mucosa was studied in vitro using Ussing type diffusion chamber. Disodium cromoglicate (DSCG, M.W.5123) and fluorescein isothiocyanate-dextran (FD) of different molecular wieghts (M.W. 4400-71200) were used as model drugs. Pemeation profiles of DSCG and FDs showed a typical pseudo steady-state curve with short lag time. The pemeability coefficient of FD (M.W. 9400) sigmodially increased with increasing STDHF concentration. It also enhanced the DSCG pemeation. Interestingly the enhancement efficacy was independent of molecular weight of penetrants.

• 한국안전학회지
• /
• 제25권6호
• /
• pp.155-160
• /
• 2010

In this study, detailed assessment for durability performance were performed on the chloride protected concrete structures to investigate the effectiveness of chloride protection. And economical efficiency for the chloride protected concrete structures were studied by LCC(Life Cycle Cost) analysis. In the comparison result of the first section repair time, it was found that the chloride protected concrete structures was economical better than the non-protected concrete structures in the long term. According to the analysis result of the accumulated chloride concentration by used time and chloride ion concentration by depth, it can be seen that the permeation through time from chloride has increased two times in the chloride protected concrete structures.

• Elastomers and Composites
• /
• 제33권3호
• /
• pp.193-200
• /
• 1998

고무소재는 다양한 종류별로 구조에 따라 다른 물성을 갖는 것으로 알려져 있다. 일반적으로 EPDM 고무는 내후성과 내오존성이 뛰어나고 열이나 냉기, 습기의 노출에도 잘 견디는 것으로 밝혀진 바 있다. 한편 crosslinked IIR은 물과 기체투과에 대한 저항성이 큰 것으로 알려져 두가지 성분의 장점을 갖도록 EPDM/crosslinked IIR의 블렌드를 새로운 형태의 소재로 추천할 수 있다. 따라서 본 실험에서는 EPDM과 crosslinked IIR의 블렌드비를 변화시키면서 가교시간과 블렌드후 물리/화학적 특성의 개선을 목표로 하였다. 결과적으로 30wt.%의 crosslinked IIR 조성을 갖는 블렌드소재가 내후성, 내오존성 및 내기체투과 특성이 뛰어나, O-링이나 전기관련 제품에 상업적으로 응용가능한 것으로 판단되었다.

• Biomolecules & Therapeutics
• /
• 제4권4호
• /
• pp.419-427
• /
• 1996

To solubilize practically insoluble biphenyl dimethyl dicarboxylate (DDB), which has been used for the treatment of chronic hepatitis as tablets or hard capsules, the solubilities of DDB in various hydrophilic, oily and hydrocarbon vehicles, and aqueous surfactant solutions were measured by high performance liquid chromatography. It was found that, among the vehicles studied, polyethylene glycol (PEG) 300 revealed the best solvency, and the solubility reached 17.6 mg/ml at 37$^{\circ}C$. The addition of glycyrrhizic acid ammonium salt (GAA) to DDB-PEG 300 solution (5-20 mg/g) inhibited the formation of precipitates, and at the concentration of 10 mg/g, any precipitaction was not observed even after 2 years at 4$^{\circ}C$. Furthermore, GAA markedly enhanced the permeation of DDB through the rabbit duodenal mucosa in a concentration dependent manner. The addition of copolyvidone (ca. 1.0%) to DDB-GAA-PEG 300 system (1 : 0.5 97.5 w/w) was most effective in preventing the considerable precipitation of DDB-PEG 300 solution (7.5 mg/750 mg) when mixed with water of 300-900 ml at 37$^{\circ}C$. GAA showed a synergistic effect in the prevention of precipitate formation. This finding suggests that this DDB formulation may form less precipitation when DDB soft capsules disintegrate and diffuse into the gastrointestinal fluid, resulting in improving the bioavailability Dissolution rate of DDB (7.5 mg) from sort elastic capsules of DDB-GAA-PEG 300 system was rapid. The supersaturation state was maintained for 2 hr at the concentration of 7.35$\pm$3.3 mg in 900 ml of water without precipitation. The total amount of DDB dissolved from this new formulation was 5.3 and 6.1 times higher, when compared to marketed DDB tablets (25 mg) and capsules (7.5 mg), respectively.