• Journal of Pharmaceutical Investigation
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• v.26 no.4
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• pp.281-289
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• 1996

In our previous work, we have studied the effect of lactose and sodium alginate (SA) on the rate of release of 5-fluorouracil (5-FU) from ethylene-vinyl acetate (EVA) matrix. These hydrophilic additives promoted the rate of 5-FU release and the increase in rate was larger when SA was used. Both additives showed better ability to increase the rate than 5-FU itself. In this paper, we extended our study to another hydrophilic additive, Carbopol 940 (CP). Compared to SA or lactose, CP increased the rate of 5-FU release markedly. Release rate increased as the loading amount and the pH of the release medium increased. After release experiment, matrix volume increased up to 15 times of that before release experiment, depending on the amount of CP dispersed in the matrix and the pH of the release medium. On the other hand, the volume of the matrix containing lactose or SA decreased. The weight changes of the dry matrix before and after release experiment imply that CP is not released out of the matrix, to the contrary of lactose and SA. Scanning electron microscope study clearly showed that large cavities and pores are generated on the surface and the inside of the matrix. These results indicate that the mechanism by which CP increases the release rate is quite different from that of monomeric additives such as lactose or SA.

• Korea-Australia Rheology Journal
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• v.14 no.1
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• pp.17-23
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• 2002

A novel and simple method using a cylindrical penetrometer is being developed for the measurement of yield stress. The principle of this technique is based on the measurement of the static equilibrium of a falling penetrometer in a yield stress fluid. The yield stress is simply determined by a balance of forces acting on the penetrometer. The yield stress of Carbopol gels and $TiO_2$ suspensions has been measured using this method. The results are in reasonable agreement with the values from conventional methods. The effects of the dimensions and weight of the penetrometer have been examined. The long-term behaviour was also observed. No measurable creep was seen and equilibrium was found to be very quickly established. The cylindrical penetrometer technique promises to be a simple, quick and reliable static method for the measurement of yield stress.

• Journal of ILASS-Korea
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• v.15 no.3
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• pp.109-114
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• 2010

The implementation of gelled propellants systems offers high performance, energy management of liquid propulsion, storability, and high density impulse of solid propulsion. The present study focused on the macroscopic spray characteristics of liquid sheets formed by triplet impinging jets of non-Newtonian liquids which are mixed by Carbopol 941 0.5%wt. The results are compared to experiments conducted on spray images which formed by triplet impinging jets concerning with airassist effect at center orifice. When gel propellants are injected by doublet impinging jets at low pressure and high pressure, closed rim pattern shape appeared by polymeric effect from molecular force and showed inactive atomization characteristics, because of extensional viscosity related by restriction of atomization process and breakup time delay of turbulence transition. As increasing mass flow rate of the air(increasing GAR), spray breakup level is also increased.

• Journal of Pharmaceutical Investigation
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• v.23 no.1
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• pp.51-53
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• 1993

Mucoadhesive tablets containing hydroxypropylcellulose-H (HPC) and carbopol 934 (CP) were prepared from direct compression. Their adhesive forces and water absorptions were investigated by using mouse peritoneal membrane and 1.5% agar plate, respectively. Adhesive force was significantly improved with increasing CP concentration, but was not affected by compression force and addition of disintegrants. And adhesive force to mouse peritioneal membrane was increased as fixing time increased. In conclusion, adequate adhesive force can be obtained by control of CP/HPC ratio and fixing time.

• The Journal of Korean Physical Therapy
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• v.14 no.2
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• pp.219-233
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• 2002

스테로이드성 소염진통제인 트리암시놀론 겔의 피부투과도를 향상시키기 위하여 초음파를 조사하여 약물의 투과도에 미치는 영향을 비교하였다. 트리암시놀론을 함유한 수용성 겔을 제조하여 물리화학적 시험을 실시하였으며 carbopol을 기제로한 겔이 우수한 제제학적 특성을 보였다. 초음파 조사가 약물의 투과도에 미치는 영향을 알아보기 위하여 hairless mouse의 적출 피부에 대한 in vitro 흡수 실험을 실시하였다. 트리암시놀론 겔 음파영동군이 트리암시놀론겔 단독 처치군에 비하여 투과도가 유의적으로 향상되었다. 특히 주파수가 1MHz인 지속초음파를 고 강도로 적용시 피부투과도의 향상이 더욱 두드러졌다. 따라서 트리암시놀론 겔 도포 후 초음파를 이용한 음파영동 경피흡수가 단독의 겔 처치보다 피부투과에 유용할 것으로 사료된다.

• Journal of ILASS-Korea
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• v.24 no.2
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• pp.82-88
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• 2019

Shear coaxial injectors were commonly used in rocket engine combustor. They showed good combustion performance. However it is not easy to control the thrust. Pintle injectors were not as popular as the coaxial injectors so far, they have a great advantage over the coaxial injectors. That is, it is relatively easy to control the thrust. Spray characteristics of gel type propellant from movable sleeve pintle injector were investigated. Water with 0.05% of Carbopol 940 was used as gel simulant instead of kerosene gel combined with Thixarol ST for academic purpose. Experiments were performed in various temperature, pressure and pintle opening condition. The results were compared with neat liquid spray. It is also verified that the capabilites of the injector by adjusting the pintle opening.

• Journal of dental hygiene science
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• v.10 no.2
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• pp.79-83
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• 2010

This study manufactured hydrogel, which was contained NSAIDs(non-steroidal anti-inflammatory drugs) Ketorolac tromethamine and hydrolyzed products of gardeniae fructus extract, and experimented viscosity, surface tension, tensile strength and bio-adhesiveness by using hairless mouse. Thus, it was performed in expectation for being probably able to develop as effective auxiliary agent of periodontal disease after non-surgical or surgical periodontal treatment. As a result, the following conclusions were obtained. 1. Out of KGE and KGH gel materials, the content of ketorolac tromethamine was 1.02~0.97%. The content of geniposide was 0.34% in KGE gel A and C. However, it got lower to 0.11% in KGH gel B and D. The content of genipin wasn't shown in KGE gel A and C, but was shown with 0.13% in KGH gel B and D. 2. As for viscosity according to temperature in gel material, the gel, which used independently Carbopol 940 as gel inoculant, maintained the higher viscosity than the gel, which added Poloxamer 407. The surface tension in each material showed 34.77~40.58 dyne/cm at 37. As for tensile strength in material, KGH gel B was shown the higher tensile strength in about 3.5 times compared to the control group. 3. As for bio-adhesiveness, the back-skin upper part(epidermis) and abdomen skin were shown to be 50.62 N in KGH gel B, thereby having indicated higher value in about 5 times compared to control group. The back-skin lower part(dermis) and abdomen skin were shown to be 35.93 N in KGH gel B, thereby having indicated higher value in about 3.5 times compared to control group.

• Applied Chemistry for Engineering
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• v.25 no.6
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• pp.570-576
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• 2014

Palmitoyl tripeptide (M330) showed higher antimicrobial activities than methyl paraben or phenoxy ethanol through minimum inhibitory concentration (MIC) test. However, when the M330 was added into cosmetic formulation, white precipitates formed due to the electrostatic interaction between M330 and carbopol (carboxy vinyl polymer) as a thickener in cosmetics, and the viscosity of cosmetics decreased sharply. Also, the antimicrobial activities of M330 in cosmetics became lower than those of methyl paraben or phenoxy ethanol. Thus, the encapsulation of M330 in ethosome vesicle was attempted in order to recover the declined antimicrobial activities of M330 in cosmetics and prevent the precipitates from forming. When ethosome-encapsulated M330 was added into cosmetics, the precipitates did not form, and the decrease in the viscosity of cosmetics was not large compared to the addition of unencapsulated M330. Challenge tests showed that antimicrobial activities against gram negative bacteria were improved by the encapsulation of M330, but the encapsulation was not effective against gram positive bacteria and fungus. A combination of M330 with EDTA showed synergistic inhibitory potential against C. albicans. After coencapsulation of M330 and EDTA in ethosome, antimicrobial activities proved to be higher than those of unencapsulated M330 and EDTA.

• Journal of Pharmaceutical Investigation
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• v.30 no.3
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• pp.167-172
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• 2000

The purpose of this study is to develop a transurethral liquid suppository containing prostaglandin $E_1\;(PGE_1)-loaded$ microemulsion, which undergoes a phase transition to gels at body temperature. The effects of oils, ethanol as solvent and HCl as pH-controlling agent on the physicochemical properties of liquid suppositories composed of poloxamer P 407, P 188 and carbopol was investigated. The stability of $PGE_1$ and release of $PGE_1$ from liquid suppository were evaluated. Oils such as Neobee and soybean oil significantly decreased the gelation temperature but increased the gel strength of liquid suppository due to their strongly binding with the components of liquid suppository base. However, ethanol slightly did the opposite. The pH of liquid suppositories hardly affected the gelation temperature and gel strength due to addition of very small HCl (0.005-0.01%). A liquid suppository [$PGE_1/P$ 407/P 188/carbopol/Neobee/ethanol/HCl (0.2/14/14/0.4/7/2/0.005%)], which had the gelation temperature $(34.2{\pm}0.6^{\circ}C)$ and gel strength $(31.35{\pm}4.37\;sec)$ suitable for liquid suppository system, was easily administered and not leak out from the body. About 60% of $PGE_1$ was released out within 2 h from this formulation. It was shown that the release of $PGE_1$ was proportional to the square root of time, indicating that $PGE_1$ might be released from the suppository by Fickian diffusion. It was stable at $4^{\circ}C$ for at least 2 months. The results suggest that transurethral liquid suppository containing prostaglandin $E_1-loaded$ microemulsion is thought to be a convenient, safe and effective dosage form for $PGE_1$. However, it should be further developed as a more convenient and stable dosage form for $PGE_1$.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.1-12
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• 2006

The purpose of this study were to evaluate the efficacy of the newly developed Digital Imaging Fiber-Optic Trans-illumination (DIFOTI) system in detecting carious lesions in vivo as gold standard with confocal laser scanning microscopy and compared the efficacy of traditional radiography and DIFOTI system in vito as gold standard with confocal laser scanning microscopy, too. For the in vivo study, the subject pool consisted of 23 grammar school age patients just prior to entering the mixed dentition phase Each patient was given a DIFOTI examination of the anterior and posterior teeth. During $6{\sim}8$ months, the naturally expire primary teeth were collected and the efficacy of DIFOTI system was compared with confocal laser scanning microscopy. For in vitro study, 40 primary teeth were collected and decalcified by Carbopol decalcification solution for 1, 2, 4 and 8 days. Every experiment period, all teeth were DIFOTI examined and sectioned to take an image of confocal laser scanning microscopy Sensitivity and specificity were calculated from the result of DIFOTI examine and confocal laser scanning microscopy analysis. The results are as follows : 1. From the in vivo study, the sensitivity of DIFOTI examine was 0. 61 and specificity was 0.63. 2. From the in vivo study, the sensitivity of DIFOTI examine was 0.71 and specificity was 0.75.