• Archives of Pharmacal Research
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• 제25권3호
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• pp.392-399
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• 2002

The effects of vehicles and penetration enhancers on the in vitro permeation of melatonin through dorsal hairless mouse skin were investigated. Propylene glycol laurate (PGL), isopropyl myristate (IPM), propylene glycol monolaurate (PGML) and propylene glycol monocaprylate (PGMC) showed high permeation fluxes and PGL, PGML and PGMC decreased lag time significantly. In both of the binary co-solvents of diethylene glycol monoethyl ether (DGME)-PGL and DGME-IPM, the highest fluxes were achieved at 20% of DGME, which were $10.5{\pm}1.5$ and $9.1{\pm}2.4{\;}{\mu\textrm{g}}/cm^2/h$, respectively. Among fatty acids used as a permeation enhancer, capric acid and oleic acid in DGME-PGL (80:20 v/v) showed relatively high enhancing effects. Capric acid also shortened the lag time of melatonin from $2.4{\pm}0.7{\;}to{\;}1.3{\pm}0.2{\;}h$. Oleic acid, however, failed to shorten the lag time. Therefore, for effective solution formulations in terms of permeation flux and lag time, capric acid-containing DGME-PGL (80 : 20 v/v) could be used to enhance the skin permeation of melatonin.

• Biomolecules & Therapeutics
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• 제7권3호
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• pp.263-270
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• 1999

The in vitro permeation of thyrotropin-releasing hormone (TRH) through rabbit nasal, rectal and duodenal mucosae was studied in the absence and presence of an enzyme inhibitor and permeation enhancer. TRH in the donor and receptor solutions was assayed by HPLC. When thimerosal (TM, 0.5 mM) was added to the donor cell as an inhibitor, the permeation rate of TRH (200 $\mu\textrm{g}$/ml) increased linearly as a function of time. Fluxes of TRH through the nasal, rectal and duodenal mucosae were found to be 33.3$\pm$5.9, 11.8$\pm$1.9 and 9.6$\pm$0.7 $\mu\textrm{g}$/$\textrm{Cm}^2$/hr, respectively. The addition of sodium glycocholate, glycyrrhizic acid ammonium salt, sodium taurodihydrofusidate or L-$\alpha$-lysophosphatidylcholine to the donor solution containing TM did not result in the significant increase of permeation flux except for the duodenal mucosa, comparing with that in the presence of TM alone. Consequently, it was suggested that the nasal route was advantageous for systemic delivery of TRH, and the addition of TM and/or an enhancer was necessary to maximize the transmucosal permeation of TRH.

• 상하수도학회지
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• 제19권1호
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• pp.25-30
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• 2005

In order to decrease the high costs of membrane process, we have tried to develop two alternatives to membrane; a cartridge type filter and a metal membrane were tested for the high permeation flux with low cost and low energy. This research mainly focused on three points; 1) operation with high permeation flux by using of a cartridge type filter and a metal membrane, 2) removals of the filterable organic materials (FOC) by pretreatments for the membrane fouling control, and 3) advanced wastewater treatment by SMBR process with intermittent aeration and high MLSS. An Intermittently aerated membrane bioreactor using a submerged micro filter (cartridge type) was applied in laboratory scale for the advanced wastewater treatment. To minimize membrane fouling, intermittent aeration was applied inside of the filter with $3.0kg_f/cm^2$. The experiments was conducted for 6 months with three different HRTs (8, 10, 12 hr) and high MLSS of 6,000 and 10,000mg/L. The filtration process could be operated up to 50 days with permeation flux of 500LMH. Regardless of the operating conditions, more than 95% of COD, BOD and SS were removed. Fast and complete nitrification was accomplished, and denitrification was appeared to be the rate-limiting step. More than 75% T-N could be removed due to the endogenous denitrification. T-P removal efficiency was increased to 80% under the condition of MLSS 10,000mg/L.

• Journal of Pharmaceutical Investigation
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• 제40권1호
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• pp.23-31
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• 2010

In our previous work on levodopa delivery at pH 2.5 using iontophoresis, we found that cathodal delivery showed higher permeation than anodal delivery and electroosmosis plays more dominant role than electrorepulsion. In this work, we studied the transdermal transport of levodopa at very low pH (pH=1.0) where all levodopa molecules are cations, and evaluated some factors which affect the transdermal transport. The transport study at pH 2.5 was also conducted for comparison. The contribution of electrorepulsion and electroosmosis on flux was also evaluated. Using stable aqueous solution, the effect of electrode polarity, current density, current type and drug concentration on transport through skin were studied and the results were compared. We also investigated the iontophoretic flux from hydroxypropyl cellulose (HPC) hydrogel containing levodopa. In vitro flux study was performed at $33^{\circ}C$, using side-by-side diffusion cell. Full thickness hairless mouse skin were used. Current densities applied were 0.2, 0.4 or $0.6\;mA/cm^2$. Contrary to the pH 2.5 result, anodal delivery showed higher flux, indicating that electrorepulsion is the dominant force for the transport, overcoming the electroosmotic flow which is acting against the direction of electrorepulsion. Cumulative amount of levodopa transported was increased as the current density or drug concentration was increased. When amount of current dose was constant, continuous current was more beneficial than pulsed current in promoting levodopa permeation. Similar transport results were obtained when hydrogel was used as the donor phase. These results indicate that iontophoretic delivery of zwitterion such as levodopa is much complicated than that can be expected from small ionic molecules. The results also indicate that, only at very low pH like pH 1.0, electrorepulsion can be the dominant force over the electroosmosis in the levodopa transport.

• Korean Chemical Engineering Research
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• 제43권2호
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• pp.243-248
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• 2005

분리막 투과증발은 증류에 비하여 낮은 에너지를 요구하기 때문에 물/유기물 혼합물의 분리에 이용될 수 있으며 공비 혼합물이나 이성질체의 분리에 선호되는 방법이다. 제올라이트 분리막은 고분자 분리막에 비하여 열적, 기계적, 화학적 안정성이 우수하며 NaA 제올라이트 분리막은 큰 친수성을 나타내므로 물/유기물 혼합물로부터 효율적인 물 분리에 적합하다. 본 연구에서는 NaA 제올라이트 분리막을 이용한 투과증발 막분리 공정을 이용하여 물/에탄올 혼합물에서 선택적으로 물을 분리하고자 하였다. 에탄올의 공급 농도가 증가함에 따라 총투과플럭스는 감소하였으며 선택도는 증가한 후 높은 에탄올 농도에서 감소하는 것을 관찰할 수 있었다. 실험 온도의 증가에 따라 총투과플럭스는 증가하였으며 선택도 또한 증가하였지만 높은 에탄올 농도에서는 감소하였다. 160시간 이상의 장기간 실험을 통하여 총투과플럭스와 선택도가 안정적으로 일정함을 확인할 수 있었다. 또한, 본 연구를 통하여 얻어진 NaA 제올라이트 분리막은 증류 및 PVA 계열 고분자 분리막보다 우수한 성능을 나타냄을 알 수 있었다.

• Archives of Pharmacal Research
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• 제24권6호
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• pp.572-577
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• 2001

The feasibility of skin penetration was studied for aspalatone (AM, acetylsalicylic acid maltol ester), a novel antithrombotic agent. In this studys hairless mouse dorsal skins were used as a model to select composition of vehicle and AM. Based on measurements of solubility and partition coefficient, the concentration of PC that showed the highest flux for AM across the hairless mouse skin was found to be 40%. The cumulative amount permeated at 48 h, however, appear inadequate, even when the PC concentration was employed. To identify a suitable absorption enhancer and its optimal concentration for AM, a number of absorption enhancers and a variety of concentration were screened for the increase in transdermal flux of AM. Amongst these, linoleic acid (LOA) at the concentration of 5% was found to have the largest enhancement factor (i.e., 132). However, a further increase in AM flux was not found in the fatty acid concentration greater than 5%, indicating the enhancement effect is in a bell-shaped currie. In a study of the effect of AM concentration on the permeation, there was no difference in the permeation rate between 0.5 and 1% for AM, below its saturated concentration. At the donor concentration of 2%, over the saturated condition, the flux of AM was markedly increased. A considerable degradation of AM was found during permeation studies, and the extent was correlated with protein concentrations in the epidermal and serosal extracts, and skin homogenates. In rat dorsal skins, the protein concentration decreased in the rank order of skin homogenate > serosal extract > epidermal extract. Estimated first order degradation rate constants were $6.15{\pm}0.14,{\;}0.57{\pm}0.02{\;}and{\;}0.011{\pm}{\;}0.004{\;}h^{-1}$ for skin homogenate, serosal extract and epidermal extract, respectively. Therefore, it appeared that AM was hydrolyzed to some extent into salicylmaltol by esterases in the dermal and subcutaneous tissues of skin. taken together, our data indicated that transdermal delivery of AM is feasible when the combination of PC and LOA is used as a vehicle. However, since AM is not metabolically stable, acceptable degradation inhibitors may be nervessary to fully realize the transdermal delivery of the drug.

• 약학회지
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• 제60권1호
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• pp.36-45
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• 2016

This study was aimed to enhance the percutaneous absorption of tizanidine hydrochloride (TZ) across Strat-M$^{TM}$ artificial membrane and excised hairless mouse skin using various vehicles and chemical permeation enhancers. Solubility studies were performed using hydrophilic and lipophilic vehicles. To initially evaluate vehicle effects on skin permeation, Strat-M$^{TM}$ membrane was adopted using Franz-type diffusion cells loaded with 0.4 mg donor dose. Effects of fatty acids on the permeation of TZ from PG and PGMC were compared, and the effects of various hydrophilic vehicles in the presence of linoleic acid were studied using excised hairless mouse skin specimens. The mean solubility (mg/ml) of TZ in hydrophilic vehicles was higher: water > PG > DMSO > ethanol > PEG 200 > NMP > PEG 300 > PEG 400 > DGME, and solubilities in lipophilic vehicles such as PGMC, PGMC, IPM, Captex 200 and Captex 300 were much less than 1.0 mg/ml. Permeation rates through StratTM membrane from pure vehicles were in the rank order: PGMC ${\geq}$ LBF > DMSO ${\geq}$ NMP ${\geq}$ PGML ${\geq}$ PG ${\geq}$ PEG 200 ${\geq}$ DGME ${\geq}$ EtOH. However, permeation rates of TZ through hairless mouse skin from pure vehicles were very low, although PG showed the highest flux ($1.66{\pm}0.28{\mu}g/cm^2{\cdot}hr$). Therefore, PG was selected in further studies. Addition of enhancers (3 v/v%) into PG markedly increased the flux (${\mu}g/cm^2{\cdot}hr$): oleyl alcohol ($14.9{\pm}3.1$) ${\geq}$ oleic acid ($14.5{\pm}1.6$) ${\geq}$ linoleic acid ($13.7{\pm}1.3$) > capric acid ($4.4{\pm}0.6$) > caprylic acid ($2.1{\pm}0.4$). Among hydrophilic vehicles with linoleic acid, PG and DMSO revealed relatively higher permeation for TZ. Increase of donor dose in PG resulted in dose-dependent permeation fluxes. These results suggest that permeation properties of TZ from nonaqueous solutions are markedly different between Strat-$M^{TM}$ membrane and excised hairless mouse skin, and transdermal delivery of TZ would be feasible with a combination of PG and enhancers.

• 한국산업보건학회지
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• 제31권2호
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• pp.173-183
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• 2021

Objectives: This study evaluated the skin permeability of lawsone in henna hair dyes to understand the exposure characteristics of henna hair dyes in the human body. It examined the protective effects of protectants by applying protectants A, B, and C to test skin. Methods: Skin absorption tests were conducted using Franz diffusion cells according to OECD test guideline 428. After applying one kind of natural henna hair dye and chemical henna hair dye, respectively, to a standardized pig skin model, samples of receptor fluid were collected at 1h, 3h, 6h, and 24h. The skin permeation of lawsone was determined using HPLC. After the skin absorption experiment, the skin to which hair dye was applied was analyzed to determine the residual amount of lawsone in the skin. Results: The cumulative permeation of both natural and chemical henna hair dyes increased over time, and the natural henna hair dye had a flux value (t=3.194, p<.05) high both in the K_p value (t=3.207, p<.05) and the residual amount (t=22.701, p<.001). For skin treated with a protectant, the cumulative permeation of natural henna hair dye 24h control and the cumulative permeation of protectant A, B, and C increased over time. Flux and K_p values were in the order control > protectant A > protectant C > protectant B. The residual amount (F=4.469, p<.05) was in the order of protectant C > protectant A > protectant B > control. At 3h, the dye application time of natural henna hair dye, the lawsone flux value (F=4.454, p<.05) and K_p value (F=4.455, p<.05) were higher in the control group than in the protectant groups. The 24h cumulative permeation of the chemical henna hair dye increased with time in both the control and the protectant groups, and the flux and K_p values were in the order of protectant A > protectant C > protectant B > control. The residual amount (F=7.901, p<.01) was in the order of protectant B > protectant A> protectant C > control. Conclusions: Within the normal dyeing time for henna hair dye (three hours for natural henna hair dyes and 30 minutes for chemical henna hair dyes) lawsone skin penetration was not observed even when no protective agent was applied. After that time, however, evidence of skin penetration and retention of lawsone and the protective effect of protective agents were observed.

• 한국세라믹학회지
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• 제56권2호
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• pp.197-204
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• 2019

An electrochemical oxygen permeating membrane (OPM) is fabricated using Zr_0.895Sc_0.095Ce_0.005Gd_0.005O_2-δ (ScCeGdZ) as the solid electrolyte and aLa_0.7Sr_0.3MnO₃-bScCeGdZ composite (LZab, electrode) as the electrode. The crystal phase of the electrode and the microstructure of the membrane is investigated with X-ray diffraction and scanning electron microscopy. The electrochemical resistance of the membrane is examined using 2-p ac impedance spectroscopy, and LZ55 shows the lowest electrode resistance among LZ82, LZ55 and LZ37. The oxygen permeation is studied with an oxygen permeation cell with a zirconia oxygen sensor. The oxygen flux of the OPM with LZ55 is nearly consistent with the theoretical value calculated from Faraday's Law below a critical current. However, it becomes saturated above the critical current due to the limit of the oxygen ionic conduction of the OPM. The OPM with LZ55 has a very high oxygen permeation flux of ~ 3.5 × 10^-6 mol/㎠s in I = 1.4 A/㎠.

• 멤브레인
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• 제22권1호
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• pp.1-7
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• 2012

니오븀 금속을 기반으로 하는 $Nb_{56}Ti_{23}Ni_{21}$ 합금 분리막의 수소 투과 특성 및 화학적 안정성에 관한 연구를 수행하였다. 이를 위하여 직경 10 mm, 두께 0.5 mm의 $Nb_{56}Ti_{23}Ni_{21}$ 합금 분리막을 제작하였으며, 2가지 조성($H_2$ 100%, $H_2$ 60% + $CO_2$ 40%)의 공급가스를 $450^{\circ}C$의 온도에서 투과시킬 때 압력에 따른 수소 투과 특성에 관한 실험을 진행하였다. 본 실험에서의 최대 수소 투과량은 순수한 수소를 투과시킬 경우 절대압력 3 bar에서 $5.58mL/min/cm^2$로 나타났다. 또한 공급가스 조성에 따른 각각의 경우 모두 Sievert's law에 잘 부합하였으며, 이산화탄소와의 혼합가스 사용시, 투과량은 수소 분압 감소에 비례하여 감소하였다. 투과 실험 후 XRD 분석을 통하여 $Nb_{56}Ti_{23}Ni_{21}$ 합금 분리막의 이산화탄소에 대한 화학적 안정성에 대한 실험을 수행하였다.