• Title/Summary/Keyword: Stability Agent

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Stabilization of Doxorubicin Hydrochloride in Injections (염산 독소루비신 주사액의 안정화)

  • Lee, Sang-Cheol;Nam, Sang-Cheol;Kim, Chun-Seong;Shin, Hyun-Jong;Paik, Woo-Hyun
    • Journal of Pharmaceutical Investigation
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    • v.24 no.3
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    • pp.109-113
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    • 1994
  • Effects of various formulation factors using $L_8$ orthogonal arrays with the stability of doxorubicin hydrochloride injections(DHls) were investigated. The degradation of DHI may be occured by pH, temperature, light and metal ions. It is known that DHI should be stored on refrigerated condition of $4{\sim}8^{\circ}C$ because of its unstability on the room temperature. The employed factors were sodium chloride as isotonic solution, sodium bisulfite or sodium pyrosulfite as an antioxidant, disodium edetate as a chelating agent, methyl parahydroxybenzoate as a dissolution time shortening agent, and hydrochloric acid or citric acid as a pH adjusting agent at $22^{\circ}C$. From the results of $L_8$ orthogonal arrays, an optimal formula, including sodium chloride, disodium edetate, sodium bisulfite and hydrochloric acid, was obtained and the shelf-life of the formula was determined as 560 days approximately.

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Study on the Cationic Dyeing Properties of Polyamide-imide Fiber using 2-Hydroxyacetophenone as a Swelling Agent (아세토페논 팽윤제를 이용한 폴리아미드-이미드 섬유의 캐치온 염색특성 연구)

  • Son, Hyun Sik;Kim, Kyung Min;Kim, Ji Hye;Sim, Ji Hyun;Park, Sung Min;Oh, Sang Yeob
    • Textile Coloration and Finishing
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    • v.27 no.4
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    • pp.301-308
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    • 2015
  • This study optimizes dyeing conditions for polyamide-imide fabric using cationic dyes. Dyeing and fastness characteristics of polyamide-imide fabric were investigated with three cationic dyes and 2-hydroxyacetophenone as a swelling agent under various dyeing conditions such as dye and swelling agent concentrations, dyeing temperature and time, pH of dye bath. The dyeing properties were evaluated in terms of dye exhaustion, K/S value and color fastness. The optimized dyeing temperature and time were $130^{\circ}C$ for 90 min for the dyes. Under weak acidic conditions in the range pH 5 to 7, the exhaustion of cationic dyes could be enhanced leading to higher adsorption. Wash and rubbing fastness properties were generally good, while light fastness was slightly low, which can be attributed to the poor photo-stability of the cationic dyes.

Study on Cu CMP by using Semi-Abrasive Free Slurry (준 무연마제 슬러리를 아용한 Cu CMP 연구)

  • Kim, Nam-Hoon;Lim, Jong-Heun;Eom, Jun-Chul;Kim, Sang-Yong;Kim, Chang-Il;Chang, Eui-Goo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05c
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    • pp.158-161
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    • 2003
  • The primary aim of this study is to investigate new semi-abrasive free slurry including acid colloidal silica and hydrogen peroxide for copper chemical-mechanical planarization (CMP). In general, slurry for copper CMP consists of colloidal silica as an abrasive, organic acid as a complex-forming agent, hydrogen peroxide as an oxidizing agent, a film forming agent, a pH control agent and several additives. We developed new semi-abrasive free slurry (SAFS) including below 0.5% acid colloidal silica. We evaluated additives as stabilizers for hydrogen peroxide as well as accelerators in tantalum nitride CMP process. We also estimated dispersion stability and Zeta potential of the acid colloidal silica with additives. The extent of enhancement in tantalum nitride CMP was verified through anelectrochemical test. This approach may be useful for the application of single and first step copper CMP slurry with one package system.

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Analysis of Wafer Cleaning Solution Characteristics and Metal Dissolution Behavior according to the Addition of Chelating Agent (착화제 첨가에 따른 웨이퍼 세정 용액 특성 분석 및 금속 용해 거동)

  • Kim, Myungsuk;Ryu, Keunhyuk;Lee, Kun-Jae
    • Journal of Powder Materials
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    • v.28 no.1
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    • pp.25-30
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    • 2021
  • The surface of silicon dummy wafers is contaminated with metallic impurities owing to the reaction with and adhesion of chemicals during the oxidation process. These metallic impurities negatively affect the device performance, reliability, and yield. To solve this problem, a wafer-cleaning process that removes metallic impurities is essential. RCA (Radio Corporation of America) cleaning is commonly used, but there are problems such as increased surface roughness and formation of metal hydroxides. Herein, we attempt to use a chelating agent (EDTA) to reduce the surface roughness, improve the stability of cleaning solutions, and prevent the re-adsorption of impurities. The bonding between the cleaning solution and metal powder is analyzed by referring to the Pourbaix diagram. The changes in the ionic conductivity, H2O2 decomposition behavior, and degree of dissolution are checked with a conductivity meter, and the changes in the absorbance and particle size before and after the reaction are confirmed by ultraviolet-visible spectroscopy (UV-vis) and dynamic light scattering (DLS) analyses. Thus, the addition of a chelating agent prevents the decomposition of H2O2 and improves the life of the silicon wafer cleaning solution, allowing it to react smoothly with metallic impurities.

Quality Properties of Lightweight Foamed Concrete with Variances in Incorporating Ratio of CKD and Adding Ratio of Stability Agent (CKD 치환율 및 증점안정화제 혼입율 변화에 따른 경량기포 콘크리트의 품질특성)

  • Shin, Hyun-Sub;Yoo, Seung-Yeup;Jeong, Wang-Bok;Pei, Chang-Chun;Kim, Seong-Soo;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2006.11a
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    • pp.67-70
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    • 2006
  • This study investigates the properties of light weight foamed concrete designed with various incorporating ratios of CKD and adding ratios of PS. Test showed that increase of CKD and PS decreased fluidity of fresh concrete, which need more addition of superplasticizer to secure proper fluidity. As for the sinking depth of specimens, using more CKD or PS decreased the value, due to the improvement of viscosity by micro particles of CKD and reduction of air loss by PS. Those methods are very effective to solve the sinking problem of light weight foamed concrete, which has been highly concerned. For the hardened concrete, compressive strength of specimens exhibited that using around 10% of CKD or 0.02% of PS increased the strength value, but decreased when incorporated or added more amounts of that, due to reduction of the sinking depth, caused by filling effect of the micro particle and improvement of the viscosity.

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Antioxidative and Antimicrobial Activities of Cassia (Cinnamomum cassia) and Dill (Anethum graveolens L.) Essential Oils

  • Chung, Hai-Jung
    • Preventive Nutrition and Food Science
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    • v.9 no.4
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    • pp.300-305
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    • 2004
  • Antioxidative and antimicrobial activities of essential oils of cassia (Cinnamomum cassia) and dill (Anethum graveolens L.) were investigated. Essential oils used in this study were added to soybean oil and stored at $65^{\circ}C$ for 9 days to examine their antioxidant activities using peroxide value (POV). The results showed that dill essential oil possessed a higher antioxidant activity than cassia essential oil. Strong antimicrobial activity was observed in cassia essential oil, whereas low activity was observed in dill essential oil against the test microorganisms. Heat stability and cell growth inhibitions were investigated with different concentrations of cassia oil. Results showed that cassia oil had thermal stability in a wide range of $70-160^{\circ}C$. Cassia inhibited cell growth of Bacillus cereus KCTC 1022, Micrococcus luteus A TCC 9341 and Escherichia coli ATCC 25922, but not great on Salmonella typhimurium ATCC 14028 at level of 200 ppm. In conclusion, the results indicate that dill essential oil could be a potential candidate for an antioxidative agent, while cassia essential oil could be suitable for use as an antimicrobial agent in the food industry.

A Study of Thermal Properties of LDPE-Nanoclay Composite Films

  • Bumbudsanpharoke, Nattinee;Ko, Seonghyuk
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.21 no.3
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    • pp.107-113
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    • 2015
  • This work focused on the study of thermal properties and kinetic behavior of LDPE-nanoclay composite films. The effect of nanoclay content (0.5, 1, 3, and 5 wt%) on thermal stability and crystallization characteristics of the nanocomposites were investigated by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The results from endothermic curve showed that the nanoclay played an important role in the crystallization of nanocomposites by acting as nucleating agent. From exothermic curve, there was a crystallization temperature shift which was attributed to crystallization process induced by nanoclay. The TGA results showed that the addition of nanoclay significantly increased the thermal stability of LDPE matrix, which was likely due to the characteristic of layered silicates/clays dispersed in LDPE matrix as well as the formation of multilayered carbonaceous-silicate char. A well-known Coats-Redfern method was used to evaluate the decomposition activation energy of nanocomposite. It was demonstrated that introducing of nanoclay to LDPE matrix escalated the activation energy of nanocomposite decomposition resulting in thermal stability improvement.

Parenteral Docetaxel Emulsion System and Its Stability

  • Kim, Hyun-Jo
    • Journal of Pharmaceutical Investigation
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    • v.39 no.1
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    • pp.13-18
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    • 2009
  • Docetaxel is an anticancer agent with low aqueous solubility. More extensive clinical use of this drug is somewhat delayed due to lack of appropriate delivery vehicles. An attempt was made to adopt an o/w emulsion as the drug carrier which incorporated docetaxel in the propyleneglycerol stabilized by a mixed-emulsifier system. A suitable formulation was found in this study: 10 mg/mL docetaxel, 10% (w/v) oil blend, 4% (w/v) PG, 3% (w/v) Solutol HS 15 in 2.25% (w/v) glycerol solution. The formulated emulsion has very good stability when stored at $40^{\cird}C$, and the docetaxel containment efficiency can be maintained above 95% and the mean emulsion diameter around $10{\mu}m$ for at least 3 months. The formulated emulsion is a promising carrier for docetaxel and other lipophilic drugs.

Preparation and stability of N-terminal PEGylated Recombinant Human Epidermal Growth Factor

  • Na, Dong-Hee;Youn, Yu-Seok;Park, Chong-Jeon;Lee, Sang-Deuk;Lee, Kang-Choon
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.415.3-416
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    • 2002
  • To improve the stability of recombinant human epidermal growth factor (rhEGF) as therapeutic agent. the N-terminal PEGylated rhEGF (N-PEG-rhEGF) was prepared by site-specific bioconjugation and the stability was investigated in rat skin wound homogenates. Two different N-PEG-rhGEFs (N-PEG5K- and N-PEG20K-rhEGF) were successfully prepared with the yields of above 70%. The PEGylation site was directly confirmed by determining the molecular mass of Lys-C digested samples using MALDI- TOF MS. (omitted)

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Synthesis and Characterization of Copolyester Sizing Agents

  • Baik, Doo-Hyun;Kim, Gil-Lae
    • Fibers and Polymers
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    • v.2 no.1
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    • pp.148-151
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    • 2001
  • The effect of main chain structure of anion-containing copolyesters on the properties of copolyester sizing agents was investigated. The copolyesters were prepared by conventional two step polymerization technique from DMT, DMI, DMS, EG, and DEG. The copolyesters synthesized were characterized by atomic absorption spectroscopy, $^1$H-NMR Spectroscopy, GC, FTIR Spectroscopy, and DSC. The solubility decreased as the DMT content increased. The copolyesters having DMT:DMI = 1:1 showed the minimum viscosity. The effect of EG content on the solution stability was not clear and the samples having high DMI content showed better solution stability. The water resistance was best when only DMI and EG were used, while it was worst when DMT:DMI was 1:0.

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