• Archives of Pharmacal Research
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• v.12 no.2
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• pp.143-147
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• 1989

The urea effect on skin permeation of clonidine was investigated to reduce a log time and to increase a permeability. ICR mouse skin and human skin were used and were assumed to be a two-layer membrane consisted of stratum corneum and viable epidermis. The urea acted as a skin denaturant and humectant in the whole epidermis. Also it enhanced the skin permeability of clonidine about 3.5 times. On the other hand, it enhanced the skin permeability by acting as a humectant in the viable epidermis. But the urea effect on the whole epidermis was shown to be greater than that on the viable epidermis. Therefore, it was found that the effect of urea was greater on the stratum corneum than the viable epidermis. Variation of enhancing effect according to the concentration of urea was not found in the range of 1% to 20%.

• The Korean Journal of Rheology
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• v.11 no.2
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• pp.159-167
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• 1999

Sandwich injection molding is one of the remarkable polymer processes recently developed from conventional injection molding. But it is almost impossible to do theoretical investigation that we've researched it through numerical simulation. In this paper, numerical simulation on the study of sandwich injection molding is based on Finite Element Method and FAN/Control Volume method. In addition to conventional filling parameter that can confirm skin polymer melt front, new filling parameters have been introduced to confirm core polymer melt front advancement. These filling parameters are defined in each layer which is divided to solve temperature field along the thickness direction. One can notice different filling patterns resulted from the variation of material properties such as viscosities and power-law indexes, and processing conditions such as switch-over times and wall temperatures. It gives us a better understanding of the sandwich injection molding process. And we can recognize that it's the core polymer spatial distribution after the completion of filling that is the most important key point to use this process for industrial molding process.

• Journal of the Korean Applied Science and Technology
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• v.17 no.2
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• pp.126-131
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• 2000

Transdermal therapeutic system(TTS) is often used as the method of drug dosage into the epidermic skin. Natural polymer were selected as ointment material of TTS. We investigated the permeation of natural polymer ointment containing drug in rat skin using horizontal membrane cell model. Permeation properties of materials were investigated for water-soluble drug such as oxiniacic acid in vitro. These results showed that skin permeation rate of drug across the composite was mainly dependent on the property of ointment base and drug. Proper selection of the polymeric materials which resemble and enhance properties of the delivering drug was found to be important in controlling the skin permeation rate. This result suggests a possible use of natural polymer ointment base as TTS of antihyperlipoproteinemic agent.

• Journal of Pharmacopuncture
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• v.18 no.3
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• pp.75-79
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• 2015

Objectives: As the peripheral part of the primo vascular system (PVS) is difficult to visualize, we used a vascular casting material Mercox injected directly into the skin to take advantage of a simple procedure to visualize PVS structures as primo vessels (PVs) and primo nodes (PNs) in the skin. Methods: Two colors of the polymer Mercox were injected into mouse skin. After a partial maceration of the whole body with potassium hydroperoxide solution, we anatomized it under a stereomicroscope to trace the Mercox that had been injected into the PVS. Results: Injection of Mercox directly into the skin allowed the PVs and the PNs to be visualized. This approach can fill the PVS when the material is ejected out of the PVs or PNs. The shapes, sizes, and topographic positions of the nodes and the vessels are the hallmarks used to identify the PVS in skin when Mercox is used as a tracer. Conclusion: The direct injection of the casting material Mercox into skin, with modified partial maceration procedures, is a promising method for visualizing the PVs and the PNs in the peripheral part of the PVS in skin. The polymer Mercox can penetrate through the primo pores of the primo vascular wall and fill the PVs and the PNs. The data prove that PVs and PNs exist on the hypodermal layer of the skin.

• Journal of Pharmaceutical Investigation
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• v.38 no.1
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• pp.45-50
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• 2008

5-Fluorouracil (5-FU) is an antimetabolic of the pyrimidine derivatives that is used in chemotherapy for the treatment of several types of cancer. 5-FU have poor oral absorption and short biological half-time and strong side effects. Microneedle introduced to find a solution of problems. Microneedle device with roll was manufactured for transdermal delivery of various drugs. 5-FU was mixed in non-ionic surfactant such as tween 20 and tween 80. Camscope was used to analysis the permeation magnitude of treated skin by microneedle and trypan blue staining. The 5-FU solution with surfactant measured by ZETA-potential analysis system for stability of solution. The skin permeation rate of 5-FU determined by HPLC. We confirmed that cross treated skin was dyed more deeply than parallel treated skin through trypan blue staining. The results indicate that skin permeation rate of 5-FU was increased with the treatment types and treatment times.

• Journal of the Korean Applied Science and Technology
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• v.25 no.2
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• pp.123-129
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• 2008

Transdermal therapeutic system(TTS) is often used as the method of drug dosage into the epidermic skin. Natural polymer were selected as ointment material of TTS. We investigated the permeation of natural polymer ointment containing drug in rat skin using horizontal membrane cell model. Permeation properties of materials were investigated for water-soluble drug such as Nicotinic acid N-oxide in vitro. These results showed that skin permeation rate of drug across the composite was mainly dependent on the property of ointment base and drug. Proper selection of the polymeric materials which resemble and enhance properties of the delivering drug was found to be important in controlling the skin permeation rate. This result suggests a possible use of natural polymer ointment base as TTS of antihyperlipoproteinemic agent.

• Journal of Pharmaceutical Investigation
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• v.28 no.1
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• pp.1-5
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• 1998

The effect of synthetic polymer membranes on the permeation rate of dideoxynucleoside-type anti-HIV drugs through hairless rat skin was studied using ethylene/vinyl acetate copolymer (EVA) and ethylene/methyl acrylate copolymer (EMA) membranes fabricated by solvent casting method. In vitro skin permeation kinetics study of DDC (2',3'-dideoxythymidine), DDI (2',3'-dideoxyinosine) and AZT (3'-azido-3'-deoxythymidine) across the (membrane/skin) composite was conducted for 24 hours at $37^{\circ}C$ using the Valia-Chien skin permeation system. The results showed that skin permeation rate of each drug across the (skin/membrane) composite was mainly dependent on the property of the membrane. Proper selection of the polymeric membrane which resembles hydrophilicity/lipophilicity of the delivering drug was important in controlling the skin permeation rate.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.322-327
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• 2015

Objectives: The major objective of this study is the oral dose toxicity test and skin irritation test of eco-friendly plasticizer using crude glycerol derived from the biodiesel process. Methods: Glyceroldiacetate laurate(GDL) was synthesized from glycerol monolaurat(GML) and acetic acid. The synthesis of the GDL plasticizer was measured with nuclear magnetic resonance spectroscop(NMR) and FT-IR(Fourier Transform Infrared Spectrometer). To provide information on the safety of GDL, we carried out an oral dose toxicity test for GDL in Sprague-Dawley rats. Also, we carried out a skin irritation test for GDL in New Zealand White rabbits. Results: The oral dose toxicity test in Sprague-Dawley rats showed that GDL is a non-toxic material. The result of the skin irritation test on New Zealand White rabbits showed that GDL is non-irritating. Conclusions: From the results of oral dose toxicity test and skin irritation test, we concluded that the developed plasticizer showed excellent eco-friendly property. Based on our results, we confirmed the development of an eco-friendly non-phthalate plasticizer. Applicability for PVC toys and food and drug packaging materials was found.

• Journal of Pharmaceutical Investigation
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• v.38 no.6
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• pp.357-363
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• 2008

Penetration rate of large molecule through skin is very low due to the barrier effect of stratum corneum. Novel microneedle treatment device with roll was designed for transdermal delivery of large molecular drugs such as vaccine and protein drugs. The permeation rates of FITC labelled bovine serum albumin (FITC-BSA) as a model protein were determined using modified Franz diffusion cell and hairless mouse skin which were treated by hydrogel or solution containing FITC-BSA. Fluorescent spectrophotometer was used to analyze the concentration of FITC-BSA. Microscope using fluorescent filter was used to capture the image and location of FITC-BSA in the skin. We confirmed that permeation rate of BSA was increased with the treatment by microneedle and was increased by the increasing frequency of treatment. Furthermore, the permeation rate observed from hydrogel treated skin was significantly higher than that from solution treated skin.

• Journal of the Korean Applied Science and Technology
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• v.27 no.2
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• pp.99-106
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• 2010

We have investigated the rheological behaviours of emulsions containing polymers. The polymers used in this study were polyacrylamide and carboxy vinyl polymer. The emulsion with polyacrylamide shows better prior preference than that with carboxy vinyl polymer on the skin texture. In the toxicity test, such as, LLNA cell toxicity, skin organ culture and human patch test, polyacrylamide was the appropriate materials for the cosmetics. The viscosity of polyacrylamide shows maximum value in neutral pH and good stability against temperature. The decreasing effect of viscosity against salt was not good enough but showed a better result than that of carboxy vinyl polymer. Two times the amount of polyacrylamide should be used for the formation of a similar viscosity of carboxy vinyl polymer. Yield value of polyacrylamide was low and the effect for the stabilizing emulsions was also low.