• Title/Summary/Keyword: Swelling-type

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Cross-Linked Starch Microspheres: Effect of Cross-Linking Condition on the Microsphere Characteristics

  • Atyabi, Fatemeh;Manoochehri, Saeed;Moghadam, Shadi H.;Dinarvand, Rassoul
    • Archives of Pharmacal Research
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    • v.29 no.12
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    • pp.1179-1186
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    • 2006
  • Cross-linked starch microspheres were prepared using different kinds of cross-linking agents. The influence of several parameters on morphology, size, swelling ratio and drug release rate from these microspheres were evaluated. These parameters included cross-linker type, concentration and the duration of cross-linking reaction. Microspheres cross-linked with glutaraldehyde had smooth surface compared with those prepared with epichlorhydrine or formaldehyde. The particle size increased with increasing the cross-linking time and increasing the drug loading. Swelling ratio of the particles was a function of cross-linker type but not the concentration or time of cross-linking. Drug release from starch microspheres was measured in phosphate buffer and also in phosphate buffer containing a-amylase. Results showed that microspheres cross-linked with epichlorhydrine released all their drug content in the first 30 minutes. However, cross-linking of the starch microspheres with glutaraldehyde or formaldehyde decreased drug release rate. SEM and drug release studies showed that cross-linked starch microspheres were susceptible to the enzymatic degradation under the influence of alpha-amylase. Changing the enzyme concentration from 5000 to 10,000 IU/L, increased drug release rate but higher concentration of enzyme (20,000 IU/L) caused no more acceleration.

Studies on the Inhibitory effect of anaphylactic reaction by Shinisan (辛夷散에 의한 아나필락시 反應의 抑制에 관한 硏究)

  • Han, Young-mok;LIm, Gyu-sang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.12 no.1
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    • pp.1-17
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    • 1999
  • Shinisan has been used for treatment of allergic disease in Oriental Medicine. However, its effect in experimental models remains unknown. The mast cell plays a pivotal role in initiating allergic response by secreting intracytoplasmic granular mediators such as histamine. The present report describes an inhibitory effect of Shinisan on mast cell-mediated immediate type allergic reactions. Topical application of compound 48/80 can induce an ear swelling response in normal ($WBB6F_1-+/+$) mice but not in the congenic mast cell-deficient $WBB6F_1-W/W^v$ mice. Shinisan inhibited concentration-dependently mast cell-dependent ear swelling response induced by compound 48/80. Shinisan inhibited concentration-dependently passive cutaneous anaphylaxis induced by anti-dinitrophenyl (DNP) IgE in rats by topical application. Shinisan also inhibited concentration-dependently the histamine release from the rat peritoneal mast cells by compound 48/80 or anti-DNP IgE. Moreover, Shinisan had a significant inhibitory effect on compound 48/80-induced systemic anaphylactic reaction. These results indicate that Shinisan inhibits immediate-type allergic reactions by inhibition of mast cell degranulation in vivo and in vitro.

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Skin Permeation and Anti-inflammatory Effects of Hydrolyzed Products of Gardeniae Fructus Extracts (치자 엑스의 가수분해에 의한 피부투과 및 항염효과)

  • Yang, Jae-Heon;Lee, Nam-Hee
    • Journal of Pharmaceutical Investigation
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    • v.34 no.2
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    • pp.115-123
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    • 2004
  • Geniposide and its related iridoid compounds have been used in traditional herbal medicine for thε treatment of Jaundice hepatic diseases and various inflammatorys. For the purpose to increase trandsdermal absorption, the hydrolyzed products of Gardeniae Furctus were identified and assayed of active ingredients and investigated trandsdermal absorption and anti-inflammatory effects. Geniposide was hydrolyzed to genipin by ${\beta}-glucosidase$ and it was suggested that genipin was more suitable form than geniposide for transdermal absorption by its lipophilic property. Using Franz type diffusion cell and the skin of hairless mouse, the permeation rate of hydrolyzed products and their emulsion preparation were determined. Genipin have more increased absorption ratio through the skin of hairless mouse than geniposide. Also, the emulsion of hydrolyzed products of extracts showed higher permeability than that of nonhydrolyzed preparations. After 9 hours $280.85\;{\mu}g/cm^2$ of genipin was absorbed and $193.52\;{\mu}g/cm^2$ in case of geniposide. The Js of geniposide and genipin were $26.27{\pm}4.11\;{\mu}g/cm^2/hr$ and $40.35{\pm}5.04\;{\mu}g/cm^2/hr$ respectively. After carrageenan injection, the swelling was increased repidly to 24 hr and maintained as plateau. but emulsion group weer reached about 2.5 mL and the swelling decreased successively form 24 hr to 72 hr. The anti-inflammation effects of extracts and hydrolyzed products emulsion were increased with significant difference with control group after 24 hr, 48 hr and 72 hr. In carrageenan induced edema, inhibition of swelling was increased in case of hydrolyzed product emulsion compare with nonhydrolyzed group at 24 hr, 48 hr and 72 hr after swelling. In histological study, the anti-inflammatory effects of hydrolyzed products were remarkable at 48 hr and 72 hr compare with nonhydrolyzed. Hydrolyzed products of Gardeniae Fructus extracts containing genipin would be a suitable preparation to increase the transdermal absorption and anti-inflammatory effects.

Relationship Between Compression Index and Swelling Index for Remolded Clays (교란점토의 압축지수 및 팽창지수의 관계에 대해서)

  • Park, Jong-Hwa;Tatsuya, Koumoto
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2002.10a
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    • pp.317-320
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    • 2002
  • The compression index, $C'_c$ and the swelling index, $C'_s$ which are obtained from the e-log p curve of the consolidation test, are used to calculate the consolidation settlement. In this research, $C'_c$ and the two new methods of $C'_s$ i.e. $C'_{s1}$, $C'_{sm}$ for remolded clays were examined with the $({\omega}_0-{\omega}_p)$ and $(e_0-e_p)$ which are satisfied with the condition and the type of soil. Moreover, the relationships of $C'_{s1}$, and $C'_{sm}$ versus $C'_c$ were obtained.

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Effect of Coloration on the Hydrophilicity and Swelling Properties of Poly-HEMA Hydrogels

  • Jang, Jin-Ho;Park, Hwa-Sung;Jeong, Yong-Kyun
    • Textile Coloration and Finishing
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    • v.19 no.2
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    • pp.7-13
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    • 2007
  • Photopolymerization of 2-hydroxyethyl methacrylate(HEMA), in the presence of ethyleneglycol dimethacrylate(EGDMA) and 1-Hydroxycyclohexyl phenyl ketone as crosslinker and photoinitiator, respectively, produced crosslinked poly-HEMA hydrogels. The hydrogels were colored by the exhaustion of vinylsul-phone-type reactive dyes. Good colorfastness to laundering was achieved when colored with C.I. Reactive Black 5. We investigated that the effect of coloration on the hydrophilicity and swelling properties of the films. More hydrophilic gel-surfaces were generated with in increase in coloration and crosslinking. Higher surface energy was observed with higher crosslinking level. The more rapid and higher water swellability of poly-HEMA gels after coloration may be resulted from a more opened gel structure by the easier hydration of the hydrophilic sulphonic acid groups of the reacted dyes in water.

AN ANALYSIS OF THE THERMAL AND MECHANICAL BEHAVIOR OF ENGINEERED BARRIERS IN A HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY

  • Kwon, S.;Cho, W.J.;Lee, J.O.
    • Nuclear Engineering and Technology
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    • v.45 no.1
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    • pp.41-52
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    • 2013
  • Adequate design of engineered barriers, including canister, buffer and backfill, is important for the safe disposal of high-level radioactive waste. Three-dimensional computer simulations were carried out under different condition to examine the thermal and mechanical behavior of engineered barriers and rock mass. The research looked at five areas of importance, the effect of the swelling pressure, water content of buffer, density of compacted bentonite, emplacement type and the selection of failure criteria. The results highlighted the need to consider tensile stress in the outer shell of a canister due to thermal expansion of the canister and the swelling pressure from the buffer for a more reliable design of an underground repository system. In addition, an adequate failure criterion should be used for the buffer and backfill.

Noninvasive study of Drug Delivery Systems using Nuclear Magnetic Resonance Microimaging (핵자기공명 현미영상법을 이용한 약물전달체계의 비파괴연구)

  • 이동훈;고락길
    • Journal of Biomedical Engineering Research
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    • v.18 no.2
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    • pp.173-178
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    • 1997
  • pH sensitive polymers have long been utilized as one important type among many interesting drug delivery systems. This is due to the reason of different pH environments in human organs, which requires different pH control mechanism depending upon the organs. In the present study the pH sensitivity was investigated for both pH sensitive and pH insensitive biopolymers using the diffusion effect along with the swelling effect. NMR microscopy was performed along with optical microscopy. For the analysis of diffusion effect, UMR Microscopy was perFormed to measure diffusion coefficients for various liquids such as distilled water, acetone and DMSO(dimethyl sulfoxide). Also, this technique is expected to contribute to the studies for many pH drug delivery systems.

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Controlled Release of Drugs from Silicone Rubber Matrices-Effects of Physical Properties of Drugs and Release Controlling Agents on Drug Release Mechanisms- (실리콘 마트릭스로부터의 약물조절 방출-약물 및 방출조절제의 물성이 방출기전에 미치는 영향-)

  • Jeon, So-Young;Lee, Seung-Jin
    • Journal of Pharmaceutical Investigation
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    • v.21 no.4
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    • pp.237-245
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    • 1991
  • Matrix type silicone rubber devices were designed for long-term implantable drug delivery system. Release controlling agents (RCA), i.e., polypropylene glycol, polyethylene glycol, were employed to control drug release from the devices. The release rate of drug from RCA dispersed silicone matrices was mainly dependent on hydrophilicity-hydrophobicity of drug and RCA. In the case of hydrophilic drug, the release from the RCA dispersed matrix was regulated by swelling kinetics. Especially when the relatively hydrophobic polypropylene glycol was used, swelling control mechanism induced zero-order release kinetics. Whereas, the release of hydrophobic drug was resulted from partition mechanism. The effect of RCA was to increase drug diffusivity.

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Electron Beam Radiation Syntheses of Carboxymethylcellulose-based Composite Superabsorbent Hydrogels: Dependence of Gel Properties on Polymer Composition and Additives (전자빔 조사에 의한 카르복시메틸셀룰로스 기반 복합 초흡수제 제조시 폴리머 조성 및 첨가물질의 종류에 따른 겔 특성 변화)

  • Sung, Yoonki;Kim, Tak-Hyun;Lee, Byunghwan
    • Clean Technology
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    • v.22 no.4
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    • pp.258-268
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    • 2016
  • In this work, carboxymethylcellulose-based composite superabsorbent hydrogels were prepared by electron beam radiation. The composition of carboxymethylcellulose (CMC) varied from 4 wt%, 5 wt%, and 6 wt% to 7 wt% based on the amount of distilled water in the syntheses of hydrogels. Graphite oxide, reduced graphene oxide, activated carbon, and bentonite were used as additives for the synthesis of composite superabsorbent. The effect of CMC composition and the type of additives on the gel properties of the prepared hydrogels was investigated. In order to verify the functional groups in the prepared materials, Fourier transform infrared spectroscopy was used. In addition, mechanical strength, gel fraction, swelling kinetics, and equilibrium swelling ratios were measured for the prepared hydrogels. Swelling experiments were carried out in distilled water, urea solution, and physiological saline water. Prepared hydrogels were reused for 5 times, and gel fraction and swelling ratio were measured at every 24 hours. Among the prepared hydrogels, $C_{5%}GO$ and $C_{5%}rGO$ exhibited excellent mechanical property and relatively high swelling ratios for urea solution and physiological saline water with promising applicability as slow-release fertilizers.

Study on Anti-allergic Effects of Electroacupuncture in Allergic Mouse Model

  • Yoon Ji-Won;Jeong Kyoung-Ah;Cho Zang-Hee;Sung Kang-Keyng
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.1
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    • pp.196-201
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    • 2006
  • Electroacupuncture(EA) is commonly used in various diseases. In the present study, the effect of EA in the allergic mouse model was examined. Allergy is generated via immunological mechanism and non-immunological mechanism. Mast cells activated dy those mechanisms get to release various substances such as histamine, leukotrienes, prostaglandin, TNF-$\alpha$, IL-4, IL-6, etc. which induce allergic reactions and the following inflammatory responses. To evaluate the anti-allergic effects of EA, mortality, ear swelling response, vascular permeability and cytokine secretion were investigated in EA group and non-EA group of which mice were compound 48/80-induced allergy model or PCA model. Compound 48/80 induces allergic reaction via non-immunological mechanism and PCA model is generated through the same mechanism with immediate-type(Type1) allergic reaction, one of immunological allergic reactions. EA inhibited compound 48/80-induced ear swelling response but did not inhibit the systemic anaphylaxis. EA also inhibited passive cutaneous anaphylaxis(PCA) activated dy anti-dinitrophenol IgE. In addition, EA inhibited IL-6 and TNF-$\alpha$ secretion from 48 h PCA in mice. These results indicate that EA may be used for the treatment of mast cell-mediated allergic diseases, especially immediate-type(Type 1) allergy and non-immunologically mediated allergy.