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β-cyclodextrin 및 그 유도체의 포접체 형성에 의한 LG 106W의 유용성 및 안정성 개선에 관한 연구
정성훈 ( Seong-hoon Jeong ),이천구 ( Cheon-koo Lee ),조완구 ( Wan-goo Cho ),강세훈 ( Seh-hoon Kang ) 대한화장품학회 1999 대한화장품학회지 Vol.25 No.1
A newly synthesized polyhydroxy aromatic compound(LG 106W) has good skin lightening effect. Inclusion complexation of LG 106W with β -cyclodextrin and its hydroxypropyl and dimethyl derivatives was studied by the solubility method, scanning electron microscopy and differential thermal analysis. A relationship between host and guest was clearly reflected in the magnitude of the stability constant(DM- β > HP- β >β -cyclodextrin). Formulation problems, which resulted from its very low solubility in aqueous solution, were resolved by the inclusion formation. LG 106W from inclusions is much more water-soluble than pure one. The improvement of pH and temperature stability correlated with the increased solubility was also observed. Inclusion complex of LG 106W had similar activity to pure LG 106W on the inhibition of melanin synthesis in B-16 melanoma cell but showed lower irritation on cultured cell test in vitro. According to the results, cyclodextrins might be one of the reliable candidates for improving the availability of LG 106W.
Corrugated cooling unit for accelerated cooling of rebar subjected to Tempcore process
Park, Chun Su,Bae, Seh Wook,Cho, Jin Rae,Lee, Habeom,Kim, Yangjin,Moon, Young Hoon Elsevier 2020 Applied thermal engineering Vol.167 No.-
<P><B>Abstract</B></P> <P>An advanced cooling unit was developed and characterized to accelerate the cooling of steel rebars during the Tempcore process. Compared to conventional flat-surfaced coolers, the newly developed cooling unit uses a corrugated surface to generate turbulence. To estimate the cooling performance of the corrugated cooler, the heat transfer coefficient during the Tempcore process was obtained using a finite-volume method. The turbulence induced by the corrugated cooler reduces the vapor volume fractions and increases the heat transfer coefficient by up to 10%. The obtained heat transfer coefficient for convective and nucleate boiling was then applied in the model to predict the volume of martensite formed in the outer layer of the bar after the Tempcore process. The corrugated cooling unit was assembled and incorporated into an experimental simulator to evaluate its ability to accelerate cooling of rebars. For rebars treated in the corrugated cooler, a 6.54% increase in the martensite volume fraction with a 13 °C decrease in the self-tempering temperature was achieved. This result confirms that the developed corrugated cooler can be a reasonable alternative to increase cooling efficiency of Tempcore facility without upgrading the capacity of the water supplying system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The turbulence induced by the corrugated cooler increases the cooling capacity. </LI> <LI> Heat transfer coefficient for convective and nucleate boiling is numerically obtained. </LI> <LI> RPI boiling model and realizable k-epsilon model are extended to the Tempcore process. </LI> <LI> 6.54% increase in the martensite volume fraction is achieved by the corrugated cooler. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
송영숙 ( Young-sook Song ),정봉열 ( Bong-yul Chung ),조완구 ( Wan-goo Cho ),강세훈 ( Seh-hoon Kang ) 대한화장품학회 2000 대한화장품학회지 Vol.26 No.1
A series of novel ascorbic acid derivatives, polyethoxylated ascorbic acid (PEAA) were synthesized by coupling ascorbic acid with polyethylene glycol (PEG) of two molecular weights (MW: 350 and 550) at the C-2 or C-3 hydroxyl group (2PEAA350, 3PEAA350, 2PEAA550, 3PEAA550) to increase the stability and retain the activity, as a skin whitening agent. Their stability, scavenging activity against free radical, inhibitoiy activity against tyrosinase and inhibitory activity of melanin synthesis in B16 melanoma cell of PEAAs were evaluated in vitro and compared with those of ascorbic acid and 3-O-ethyl ascorbic acid (30EAA), a known stable vitamin C derivative. Among PEAAs, 2PEAA350 and 2PEAA550 liad high scavenging activity against free radical, inhibitoiy activity against tyrosinase and inhibitoiy activity of melanogenesis but low stability. 3PEAA350 had high stability and moderate scavenging activity against free radical, inhibitoiy activity against tyrosinase and inhibitoiy activity of melanogenesis. The stability, scavenging activity against free radical and inhibitoiy activity of melanogenesis of 3PEAA350 were higher than those of 30EAA. The most stable 3PEAA350 among PEAAs was nontoxic in various toxicological tests. These results suggest that PEAA would be a good whitening agent for enhancing stability and bioavailability.
EVALUATION OF IN VITRO SKIN PERMEATION OF UV FILTERS
( Young-sook Song ),( Hyo-joong Kim ),( Cheon-koo Lee ),( Wan-goo Cho ),( Seh-hoon Kang ) 대한화장품학회 1998 대한화장품학회지 Vol.24 No.3
The skin permeation and the skin primary irritation of two UV filters from caprylic capryl triglyceride (oil), oil in water (O/W) and water in oil (W/O)) emulsions, were evaluated. We selected octyl meth- oxycinnamate (OMC) broadly used in cosmetics and polymeric sunscreen agent (PSA, average MW: 2,000) synthesized by the coupling reaction of 2-ethylhexyl 4-hydroxycinnamate with poly vinylbenzyl chloride, as model UV filters. For in vitro skin permeation experiments, Franz diffusion cells (effective diffusion area: 1.766cm) and the excised skin of female hairless mouse aged 8 weeks were used. Oil or emulsion containing UV filters was applied in the donor compartment. The skin primary irritation was evaluated with female guinea pigs (8-10 weeks, 350-400 g). In oil and emulsions, the skin permeability and the skin primary irritation of PSA were lower than those of OMC. The skin permeability of UV filters was lower when they were in oil-in-water emulsion (O/W) than water-in-oil emulsion (W/O). We suggest that O/W system would be more useful when compared with W/O system, and PSA could be a good candidate for a future sunscreen agent for reducing the skin irritation.
DEVELOPMENT OF POLYETHOXYLATED RETINAMIDE AS AN ANTI-AGING AGENT
( Young-sook Song ),( Bong-yul Chung ),( Min-youl Chang ),( Mun-eok Park ),( Sung-jun Lee ),( Wan-goo Cho ),( Seh-hoon Kang ) 대한화장품학회 1999 대한화장품학회지 Vol.25 No.4
A novel retinol derivative,polyethoxylated retinamide (Medimin A) was synthesized, as an antiaging agent. Collagen synthesis, skin permeation, stability, and toxicity of Medimin A were evaluated and compared with those of retinol and retinyl palmitate. In vitro collagen synthesis was evaluated by quantitative assay of [<sup>3</sup>H]*proIine incorporation into collagenase sensitive protein in fibroblast cultures. For in vitro skin permeation experiments, Franz diffusion cells (effective diffusion area: 1.766 (cm<sup>2</sup>) and the excised skin of female hairless mouse aged 8 weeks were used. The stabilities of retinoids were evaluated at two different temperature (25 °C and 40 °C) and under UV in solubilized state and in OAV emulsion. To estimate the safety, acute oral -toxicity, acute dermal toxicity, primary skin irritation, acute eye kritation and human patch test were performed. The effect of Medimin A on collagen synthesis was similar to that of retinol. The skin permeability of Medimin A was higher than those of retinol and retinyl palmitate. The Medimin A was more stable than retinol and retinyl palmitate. Medimin A was nontoxic in various toxicological tests. These results suggest that Medimin A would be a good anti-aging agent for enhancing bioavailability and stability.
Cryptotanshinone for Treating Acne Vulgaris
( Nae-gyu Kang ),( Ji-eun Park ),( Young-sook Song ),( Jung-ah Kim ),( Mun-eok Park ),( Yong-hwa Lee ),( Jong-tae Lee ),( Wan-goo Cho ),( Seh-hoon Kang ) 대한화장품학회 2002 대한화장품학회지 Vol.28 No.1
Tests of stability and toxicity, and clinical evaluation of anti-acne activity suggest that cryptotanshinone, a constituent of the roots of Salvia miltiorrhiza Bunge, is an effective active ingredient for acne vulgaris treatments. Acne vulgaris, called acne or pimples, is the most common disease of the pilosebaceous follicle unit of the skin. It affects nearly 80% of people between the ages of 11 and 30. Approximately 30% of teenagers have acne of sufficient severity to require medical treatment. Acne is a follicular disorder of the skin. It occurs in specialized pilosebaceous units on the face and body. Acne develops when these specialized follicles undergo pathologic alterations that result in the formation of non-inflammatory lesions (comedones) and inflammatory lesions (papules, pustules and nodules). An abnormality of keratinizing epithelium of these follicles, thought to be due to the action of sebum synthesized and secreted by the androgen-sensitive sebaceous glands, leads to inflammation induced by the follicular bacterium Propionibacterium acnes. Therapy involves treatments that modify these pathogenic factors and includes drugs with antikeratinizing, antibacterial and antiseborrheic actions. Acne vulgaris is a very frequent disease, seen primarily in adolescents, involving the sebaceous follicles. Acne vulgaris is characterized by a great variety of clinical inflammatory and non-inflammatory lesions: comedones, papules, pustules, nodules, cysts and scars. Acne vulgaris is a multi-factorial disease. Although its pathogenicity is unclear, extensive studies have shown that hyperseborrhea, superinfection by P. acnes and endocrinologic androgenic changes play a role in the development of acne vulgaris.