• 대한화장품학회지
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• 제40권2호
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• pp.141-153
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• 2014

본 연구는 화장품 제형 적용성이 높은 콜레스테릭 액정(CLCs) 개발에 관한 것이다. 비동물성 원료는 동물성 바이러스 감염 이슈로부터 자유롭고 화장품 소비자들에게 안심감을 줄 수 있기 때문에 비동물성 유래로부터 콜레스테릭 액정연구를 진행하였다. 따라서 발효로부터 만들어진 비동물성 콜레스테롤[NAB cholesterol (ARCH LONZA)]을 이용하여 3 가지 새로운 콜레스테릭 유도체(CI, CC, CN)를 합성하였다. 그리고 제형 적용성이 높은 콜레스테릭 액정개발을 위해서 넓은 온도범위에서 발색을 유지하는 최적 조성연구를 진행하였다. 콜레스테릭 액정은 3 가지 유도체를 조합하여 41개의 액정을 제조하고 온도에 따른 육안평가를 통해서 색을 나타내는 범위를 평가하였다. 제조된 41개의 액정을 온도에 따라 UV-VIS 스펙트럼을 동시에 분석할 수 있는 새로운 평가법을 사용하였으며 205개의 스펙트럼 분석하고 액정에 영향을 미치는 인자와 특성을 파악하였다. 위와 같은 결과를 토대로 제형적용성이 높은 비동물성 콜레스테릭 액정 A4, A5, A6, A7의 조성을 개발하였다. 또한 인공피부를 이용한 평가를 통하여 A6 조성의 뛰어난 피부 보습효능을 확인하였다.

• 청정기술
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• 제28권4호
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• pp.293-300
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• 2022

그래핀의 우수한 기계적, 전기적, 열적 성질은 최근 몇 년 동안 여러 연구 분야에서 지대한 관심을 불러일으켰다. 그래핀을 생산하는 대표적인 방법인 습식공정 중 액상박리(liquid-phase exfoliation, LPE)는 초음파 및 높은 전단응력을 이용하여 벌크흑연을 그래핀으로 박리하는 기술이다. 액상박리에 의해 생산된 그래핀 분산액은 그래핀 잉크로 전환되어 그 활용폭을 더 넓힐 수 있는 장점이 있지만 고품질의 그래핀을 생산하고 가격경쟁력을 확보해야 한다. 위 조건을 만족하기 위해서 그래핀을 효율적으로 박리할 수 있는 공정 확보와 더불어 상대적으로 가격이 저렴한 천연흑연 기반의 그래핀 분산액 및 잉크를 생산해야 한다. 본 연구에서는 합성흑연 보다 약 3배 정도 저렴하고 그 크기는7배 이상 큰 천연흑연을 흐름반응기 액상박리 공정을 이용하여 박리를 시도하고 공정의 최적화와 박리된 그래핀의 구조적, 전기적 특성을 분석하였다. 천연흑연 기반 그래핀의 전기적 특성을 분석하기 위해 잉크 정제화 공정을 거쳐 그래핀 잉크를 생산하고 인쇄 장비를 사용하여 그래핀 패턴을 제작하였다. 본 연구를 통해 보다 경제적인 그래핀 분산액 및 잉크를 생산하고 그래핀 인쇄 소자를 개발할 수 있는 방법을 제시할 수 있을 것으로 기대된다.

• 대한본초학회지
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• 제29권6호
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• pp.1-6
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• 2014

Objectives : This study was aimed to compare Gyejibokryeong-hwan (GBH) decoctions produced using different pressure levels for various extraction times to find the optimal extraction conditions through extraction yield, total soluble solids content (TSSC), hydrogen ion concentration (pH), and the contents of chemical compounds. Methods : Decoctions of GBH were prepared under the pressure levels of 0 or $1kgf/cm^2$ for 30-180 min using water as extraction solvent. The extraction yield, TSSC, and pH were measured, and the amounts of the chemical compounds were determined using high performance liquid chromatography-photodiode array detector. Results : The higher pressure and longer extraction time increased the values of TSSC and extraction yield, while decreased the pH value. The decoctions produced in 180 min by pressurized method and produced in 150 min by non-pressurized method showed maximum values of extraction yield and TSSC with minimum value of pH. The amounts of chemical compounds showed variations in pressurized and non-pressurized decoction during overall extraction times. The influences of pressure and extraction time on extraction yield, TSSC, pH, and the contents of chemical compounds were confirmed by regression analysis, which showed that all extraction values were significantly affected by at least one of two extraction factors, pressure and extraction time. Conclusions : This study suggests that the pressure and extraction time can significantly affect the extraction efficiency of components from GBH decoctions. However, optimal extraction conditions could not be chosen due to the variation of the amounts of chemical compounds.

• 생약학회지
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• 제47권4호
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• pp.366-373
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• 2016

Bulhwangeumjeonggisan (BHGJGS) is a traditional herbal formulation generally used in the treatment of cold and gastritis. BHGJGS consists of eight herbal plants; Atractylodis Rhizoma, Magnoliae Cortex, Citri Pericarpium, Glycyrrhizae Radix, Agastachis Herba, Pinelliae Rhizoma, Zingiberis Rhizoma and Zizyphi Fructus. Complete standardization of this formulation has not been done yet. So, a simple and accurate method was developed and validated using Ultra Performance Liquid Chromatography (UPLC) with Diode Array Detector (DAD) for the standardization of BHGJGS. UPLC conditions were optimized using a c18 RP-Amide column with mobile phase; 0.1% phosphate buffer and acetonitrile, detection wavelength; 210 and 325 nm. The linearities of calibration curves were acceptable ($R^2$>0.9994), and the limit of detection and quantification were within the ranges of 0.011-0.091 and $0.034-0.277{\mu}g/ml$ respectively. The relative standard deviation (RSD) of intra- and inter-day precisions were under 3.61%. The RSD of repeatability was under 0.68 %. The results of recovery test were 94.4-107.9%, and the RSD were under 4.6%. The developed method was used to find the contents of standard constituents in BHGJGS mix extract powder, and two commercial formulation (A and B). The data show that the developed method was specific, sensitive, accurate, and precise for analysis of BHGJGS components.

• 분석과학
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• 제31권5호
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• pp.179-184
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• 2018

Diphencyprone (DPCP) is frequently used as a compounded preparation in dermatology for the treatment of alopecia and recalcitrant warts based on the immune reaction of skin allergy. However, DPCP is a non-recognized agent in Pharmacopoeia, because there are no criteria or analytical method for quality control of its powder and formulation. DPCP is unstable under light irradiation because as it easily decomposes to diphenylacetylene (DPA). This study aims to develop a simultaneous HPLC analytical method for analyzing DPCP and DPA in the raw materials and compounded preparation. The method required a C18 column ($250{\times}4.6mm$, $5{\mu}m$) at $40^{\circ}C$ with a mobile phase of (A) 0.01 M phosphoric acid in water and (B) acetonitrile at UV 220 nm. DPA conversion to DPCP in the powder and compounded preparations was accelerated after light exposure for 60 min. In addition, this resulted in different patterns depending on the wavelength of light and the formulation. That is, DPCP in compounded preparation was more unstable than that in the powder. However, the DPCP formulation in amber bottles was observed to remain stable, although the measured concentrations of DPCP were somewhat different from the nominal concentration of the compounded preparations. The control of the exact concentration is required for effective disease treatment, depending on the state of the patient. In conclusion, these results will be useful for the recognition of DPCP in Pharmacopoeia and new DPCP formulation development to prevent photodecomposition.

• 대한한의학회지
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• 제34권4호
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• pp.12-20
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• 2013

Objectives: This study compared Gumiganghwal-tang (GGT) decoctions produced using different pressure levels for various extraction times to determine the optimal extraction conditions through hydrogen ion concentration (pH), total soluble solids content (TSSC), extraction yield, and content of chemical compounds. Methods: Decoctions were prepared by the pressure levels of 0 or $1kgf/cm^2$ for 30-180 min. The pH and TSSC were measured, the extraction yield was calculated, and the amounts of the chemical compounds were determined using high performance liquid chromatography. Results: The higher pressure and longer extraction time decreased the pH value, while those conditions increased TSSC and extraction yield: the decoction produced in 180 min by pressurized method showed the minimum value of pH, but maximum values of TSSC and extraction yield. The chemical compounds showed higher amounts in decoctions produced by non-pressurized methods than pressurized methods and their amounts were decreased over the peak extraction time in both pressurized and non-pressurized methods. The results of regression analysis confirmed the correlative influences of the pressure and extraction time on pH, TSSC, and extraction yield. Conclusions: This study suggests that pressure and extraction time influence the compositional constituents in GGT decoctions, and the non-pressurized method for 120 min should be chosen as the optimal extraction condition for the preparation of GGT decoction.

• 대한한의학방제학회지
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• 제22권2호
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• pp.15-24
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• 2014

Objectives : Gwakhyangjeonggi-san (GJS) which consists of 13 herbal medicines has been used to treat gastrointestinal disorders caused by common cold. This study was performed to compare GJS decoctions produced using different pressure levels for various extraction times. Methods : Decoctions were prepared by the pressure levels of $0kgf/cm^2$ (non-pressurized) or $1kgf/cm^2$ (pressurized) for 30-180 min. The extraction yield, total soluble solid content (TSSC), and hydrogen ion concentration (pH) were measured, and the contents of the nine marker compounds were determined using high performance liquid chromatography. Results : The higher pressure and longer extraction time significantly increased TSSC value, while decreased the pH value. However, only extraction time affected the extraction yield of pressurized decoction. Variation of the amounts of chemical compounds was shown in pressurized and non-pressurized decoctions during extraction time. The result of regression analysis showed that pressure and extraction time can influence to extraction yield, TSSC, pH, and the content of chemical compounds. Conclusions : This study suggests that the pressure and extraction time can significantly affect the extraction efficiency of components from GJS decoctions.

• 대한본초학회지
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• 제28권4호
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• pp.1-6
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• 2013

Objectives : In other to determine the optimal extraction conditions, the various Bojungikgi-tang (BJIGT) decoctions prepared by different pressure levels and different extraction times were compared and evaluated in terms of the extract yield and the total soluble solid content. Methods : Decoctions were prepared by the pressure levels of 0 (non-pressurized) and 1 $kgf/cm^2$ (pressurized) for 60, 120 and 180 min. The extract yield and the total soluble solids content of decoctions were measured, and the amounts of the reference compounds in decoctions were investigated by the analysis using high performance liquid chromatography. Results : The extract yield and the total soluble solid content were higher in decoctions extracted by the pressurized method than those from decoction with non-pressurized method. The patterns of yield and contents showed a proportional increase to the extraction time. In analysis of the linear regression for four reference compounds such as liquiritin, nodakenin, hesperidin, and glycyrrhizin, the good linearity with the correlation coefficient more than 0.9999 was observed. The highest contents for four reference compounds were observed at 180 min of both the pressurized method and the non-pressurized method. Conclusions : This study suggests that the pressure in extraction method and the extraction time affect the compositional constituents in BJIGT decoctions. The extraction time of 180 min could be chosen in both pressurized and non-pressurized method as optimal extraction condition.

• 분석과학
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• 제36권1호
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• pp.32-43
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• 2023

This study reports for the first time about a stability indicating RP-HPLC method for qualitative and quantitative determination of acalabrutinib in bulk and dosage form and in presence its impurities 1, 2 and 3. The chromatographic separation was carried on Zorbax XDB-C18 (250×4.6 mm; 5 µ id) as stationary phase, Phosphate buffer pH 6.4 and methanol 80:20 (v/v) as mobile phase at a flow rate of 1.0 mL/min, UV detection was carried at wavelength of 238 nm and the analysis was completed with a run time of 15 min. In these conditions the retention time of acalabrutinib and its impurities 1, 2 and 3 was observed to be 3.50, 4.83, 8.40 and 9.93 min respectively. The method was validated for system suitability, range of analysis, precision, specificity, stability and robustness. Spiked recovery at 50 %, 100 % and 150 % was carried for both standard and impurities and the acceptable % recovery of 98-102 was observed for acalabrutinib and both impurities studied and the % RSD in each spiked level was found to be less than 2. Stability tests were done through exposure of the analyte solution to five different stress conditions i.e expose to 1N hydrochloric acid, 1 N sodium hydroxide, 3 % peroxide, 80 ℃ temperature and UV radiation at 254 nm. In all the degradation condition, standard drug acalabrutinib was detected along with both the impurities studied and the degradation products were successfully separated. In the formulation analysis there is no other chromatographic detection of other impurities and formulation excipients. Hence the developed method was found to be suitable for the quantification of acalabrutinib and can separate and analyse impurities 1 and 2.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.765-768
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• 1998

Level set method is used for extracting a shape within an image. This method is based on the ideas developed by osher and sethian to model propagating solid/liquid interfaces moving with curvature-dependent speeds. In this paper, we propose the new generalized formulation and stopping function of evolution for more accurate extraction of shape. Our method shows good results in some cases compared with the conventional ones.