• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.274-279
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• 2012

The objective of this study was to develop oral matrix tablets for the sustained release of vitamin C. In this study hydroxypropyl methylcellulose (HPMC) has been utilized as an excipient, as it is one of the most widely used polymers, for use during long periods of time in formations. The vitamin C tablet formulation depends on the molecular weight and concentration of sustained-delivery in HPMC. Anti-oxidants have been added as a dissolution medium in order to prevent vitamin C degradation in water. The dissolution test was carried out in a distilled water medium, and the release model equation was applied to analyze the vitamin C release pattern. The results demonstrated that the release and lasting power of vitamin C tablets, containing HPMC, lasted for more than 12 h.

• KSBB Journal
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• v.31 no.4
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• pp.219-227
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• 2016

Valsartan, a drug for the treatment of cardiovascular disease, exhibited low bioavailability which was caused by, at least in part, limited solubility at low pH. Present investigation deals with the preparation and characterization of gastro-retentive drug delivery system (GRDDS) using valsartan solid dispersion. We prepared solid dispersion using surfactants (Poloxamer 407) and alkalizer ($Na_2CO_3$) which may to be useful for improving solubility of valsartan at low pH and evaluated by saturated solubility of valsartan in distilled water. Valsartan gastro-retentive (GR) tablets containing solid dispersion prepared and evaluated by weight variation, floating time and dissolution rate. Compression at lower pressures resulted in the tablets floating over simulated gastric fluid (pH 1.2) for more than 17 h. In vitro release of valsartan from GR tablet was dependent on the amount of poloxamer 407 and hydroxypropyl methylcellulose. On the basis of evaluation parameter, formulation E-3 was selected as a final formulation. Therefore, it can be concluded that the GR tablets containing solid dispersion may be exploited successfully for the delivery of poorly drug such as valsartan.

• Journal of environmental and Sanitary engineering
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• v.12 no.3
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• pp.87-94
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• 1997

Influences of clotrimazole on the blood cholesterol and HDL-cholesterol level were studied in rats. Rats were provided food and water ad libitum and clotrimazole and methylcellulose were gavaged for 6 days. Clotrimazole was suspended in 1% methylcellulose solution as and administered at concentration 20mg/Kg, 40mg/Kg, 60mg/Kg. Body weight gain and liver weight/body weight ratio, serum cholesterol level, serum HDL-cholesterol level, serum triglyceride level, the activity of cytochrome p450 and erythromycin demethylase were determined at 6th day. Clotrimazole decreased the body weight gain a little as compared with control group and did not show any influence on liver weight/body weight ratio. Clotrimazole increased the serum HDL-cholesterol and serum triglyceride level significantly. Clotrimazole increased the microsomal cytochrome P450 significantly and increased the erythromycin demethylase (cytochrome P450 IIIA) significantly too. It might be conclued that clotrimazole showed a little influence on body weight and increased the serum lipid, especially HDL-cholesterol level. It also increased microsomal cytochrome P450 IIIA significantly. It might be concluded that clotrimazole showed a corelative influence between HDL-cholesterol and cytochrome P450 IIIA. In these results clotrimazole can be used as an anti-atherosclerotic agent by increasing the HDL-cholesterol but it is necessary that cloreimazole will show any adverse or side action on body or not.

• Archives of Pharmacal Research
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• v.29 no.10
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• pp.928-933
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• 2006

Percutaneous delivery of NSAIDs has advantages of avoiding hepatic first pass effect and delivering the drug for extended period of time at a sustained, concentrated level at the inflammation site that mainly acts at the joint and the related regions. To develop the new topical formulations of pranoprofen that have suitable bioadhesion, the gel was formulated using hydroxypropyl methylcellulose (HPMC) and poloxamer 407. The effects of temperature on drug release was performed at $32^{\circ}C$, $37^{\circ}C$ and $42^{\circ}C$ according to drug concentration of 0.04%, 0.08%, 0.12%, 0.16%, and 0.2% (w/w) using synthetic cellulose membrane at $37{\pm}0.5^{\circ}C$. The increase of temperature showed the increased drug release. The activation energy (Ea), which were calculated from the slope of lop P versus 1000/T plots was 11.22 kcal/ mol for 0.04%, 10.79 kcal/mol for 0.08%, 10.41 kcal/mol for 0.12% and 8.88 kcal/mol for 0.16% loading dose from the pranoprofen gel. To increase the drug permeation, some kinds of penetration enhancers such as the ethylene glycols, the propylene glycols, the glycerides, the non-ionic surfactants and the fatty acids were incorporated in the gel formulation. Among the various enhancers used, propylene glycol mono laurate showed the highest enhancing effects with the enhancement factor of 2.74. The results of this study suggest that development of topical gel formulation of pranoprofen containing an enhancer is feasible.

• Korean Journal of Materials Research
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• v.4 no.7
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• pp.808-816
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• 1994

The work present here shows the technique to produce p-Doped polypyrrole particles by semibatch dispersion polymerization using steric-stabilizer. Monomer-starved polymerization process was successful to increase the particle size up to 50 nm in case of polyvinylalcohol (PVA) stabilizer, and up to 95 nm in case of methylcellulose stabilizer. The particle size and the bulk conductivity changed with the feed rates of monomer, the concentrations of initiator (dopant) and the type, molecular weight, concentrations of steric-stabilizer.

• Development and Reproduction
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• v.9 no.2
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• pp.105-114
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• 2005

Embryonic stem(ES) cells have tremendous potential as a cell source for cell-based therapies. Realization of that potential will depend on our ability to understand and manipulate the factors that influence cell fate decision and to develop methods for getting enough cell numbers for clinical applications. Hematopoiesis has been widely studied, and hematopoietic differentiation from ES cells is a good model to study lineage commitment. In this study, we investigated stemness and compared the efficiency of hematopoietic differentiation using two different mouse embryonic stem cell lines TC-1 and B6-1. Although the two cell lines showed known stem cell properties with minor differences, the embryoid body formation efficiency in methylcellulose was much higher in TC-1 than B6-1. When measured potentials of hematopoietic differentiation using functional(colony-forming cell) and phenotypic(specific marker expression) assays, we found that TC-1 can differentiate into hematopoietic cells in methylcellulose culture but B6-1 cannot. These results imply that we can improve the efficiency of hematopoietic cell differentiation by selection of proper cell lines and this may be also applied in the differentiation of human embryonic stem cells.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1146-1152
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• 2005

Graft copolymers were synthesized from methylcellulose(MC) and acrylic acid(AA) with active carboxyl groups in the presence of potassium persulfate($K_2S_2O_8$) initiator to enhance adsorption capacity of toxic heavy metal such as $Pb^{2+}$ and $Cu^{2+}$ from wastewater. The resulting grafted copolymers(MC-g-AA/PAA) were mixture of the graft copolymers from MC and AA(MC-g-AA) and polyacrylic acid homopolymers(PAA). The degree of palling was increased with rising concentration of monomer and initiator under the reaction conditions at $60^{\circ}C$, 3 hrs. The water insoluble property of MC-g-AA showed more than 19.7% degree of grafting. So that it could be an adsorbent of heavy metals. Adsorption characteristics of the MC-g-AA were evaluated depending on the degree of grading, pH of wastewater, adsorption time, dosage of MC-g-AA and concentration of heavy metals in the different conditions. Degree of grafting, and initial concentration of heavy metal ions increased, the adsorption amount of $Pb^{2+}$ and $Cu^{2+}$ increased, but added MC-g-AA increased, the adsorption amount per unit weight of $Pb^{2+}$ and $Cu^{2+}$ decreased. The MC-g-AA showed the high $Pb^{2+}$ and $Cu^{2+}$ adsorption amount in the range pH $4{\sim}6$. Also all of $Pb^{2+}$ and $Cu^{2+}$ ions reached in adsorption equilibrium in neighborhood 4 hours. The adsorption of heavy metals described by Freundlich isotherm, it was determined the value of l/n of $Pb^{2+}$ and $Cu^{2+}$ that 0.4294 and 0.3453, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1271-1277
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• 2008

Competitive displacement of methylcellulose (MC) absorbed at the oil-water interface was investigated by interfacial composition, surface shear viscosity, or surface tension measurements. It was found that all emulsifiers could competitively displace the interfacial MC from the oil-water interface but their behaviors were different from each other. With Tween 20 added to MC emulsion (1 wt% MC, 10 wt% n-tetradecane, 20 mM bis-tris, pH 7), MC load was steadily decreased with increasing concentrations of the emulsifier, as confirmed by surface shear viscosity measurements; moreover, there was complete MC displacement from the emulsion droplet surface at high concentration (0.1 wt%). The oil-soluble Span 80 was found to show a synergism with MC at the interface, which resulted in higher MC load at relatively low emulsifier concentrations ($\leq$0.05 wt%). At a higher emulsifier concentration (0.1 wt%) limited MC displacement was observed. These results were well supported by surface shear viscosity measurements. With water-soluble SDS, MC load was decreased with increasing concentrations of the emulsifier. Unlike Tween 20, however, it was found that at high concentrations (> 0.1 wt%), there was still some MC remaining at the droplet surface. Surface tension measurements are suggestive of an interfacial complex between MC and SDS.

• Journal of Marine Bioscience and Biotechnology
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• v.7 no.2
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• pp.58-70
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• 2015

Injectable RGD-bioconjugated Mussel Adhesive Proteins (RGD-MAPs) composite hydroxypropyl methylcellulose (HPMC) hydrogels provide local periodontal tissue for bone filling in periodontal surgery. Previously we developed a novel type of injectable self-supported hydrogel (2 mg/ml of RGD-MAPs/HPMC) based porcine nano hydroxyapatite (MPH) for dental graft, which could good handling property, biodegradation or biocompatibility with the hydrogel disassembly and provided efficient cell adhesion activity and no inflammatory responses. Herein, the aim of this work was to evaluate bone formation following implantation of MPH and collagen membrane in rabbit calvarial defects. Eight male New Zealand rabbits were used and four circular calvarial defects were created on each animal. Defects were filled with different graft materials: 1) collagen membrane, 2) collagen membrane with MPH, 3) collagen membrane with bovine bone hydroxyapatite (BBH), and 4) control. The animals were sacrificed after 2 and 8 weeks of healing periods for histologic analysis. Both sites receiving MPH and BBH showed statistically increased augmented volume and new bone formation (p < 0.05). However, there was no statistical difference in new bone formation between the MPH, BBH and collagen membrane group at all healing periods. Within the limits of this study, collagen membrane with MPH was an effective material for bone formation and space maintaining in rabbit calvarial defects.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.3
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• pp.311-316
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• 2008

Calcium phosphate cement (CPC) has been used as bone substitute successfully due to good biocompatibility and osteoconductivity. One of the important mechanical characteristics of CPC is flowablility, which can be evaluated by measuring rheological parameters. However, there have been few studies that measured rheological properties of CPC. The purpose of this study was to evaluate the rheological properties of CPC paste mixed with 2 kinds of setting solutions, 2% hydroxyprophyl methylcellulose (HPMC) and 35% polyacrylic acid (PAA). The CPC used was dicalcium phosphate dihydrate (DCPD). Rheological properties of CPC paste were measured using rheometer. The statistical analysis was carried out with Mann-whitney test with Bonferronis collection. CPC with both setting solutions showed shear thinning behavior. CPC with 2% HPMC showed signigicantly higher complex viscosity than CPC with 35% PAA(p<0.05).