• YAKHAK HOEJI
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• v.38 no.4
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• pp.372-378
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• 1994

Choleretic effect and absorption of ursodeoxycholic acid (UDCA) in rats were studied using UDCA alone and it's ${\beta}-cyclodextrin$ $({\beta}-CyD)$ inclusin complex (UDCA-IC). In spite of increase in solubility and dissolution rate, absorption of UDCA-IC was decreased compared with UDCA alone. Choleretic effect of UDCA-IC was also decreased. It looks that UDCA forms stronger inclusion complex with ${\beta}-CyD$ than any other drug or organic biological material. From this study, it was suggested that UDCA might be used as a new potential competing agent when inclusion complexes of drugs with ${\beta}-CyD$ were administered for the improvement of poor bioavailability.

• Journal of Pharmaceutical Investigation
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• v.27 no.1
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• pp.29-38
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• 1997

Precipitation was formed during the preparation of decoction from a mixture of Scutellariae Radix and Coptidis Rhizoma. Baicalin and berberine were identified in this coprecipitated product (CPP) and these components were the active ingredients of two herbal medicine. We extracted respectively crude baicalin and berberine in Scutellariae Radix and Coptidis Rhizoma and prepared coprecipitate of crude baicalin-berberine. To increase the stability and bioavailability of coprecipitate of crude baicalin-berberine(CBB), which is slightly soluble drug, its inclusion complex was prepared and studied in this experiment. Inclusion complex of CBB with ${\beta}-cyclodextrin(CBB-{\beta}-CD)$ was prepared by freeze drying method and its characteristics were ascertained by means of solubility test, differential thermal analysis(DTA) and scanning electron microscope(SEM). The type of $CBB-{\beta}-CD$ is classified as $A_L-type$ on phase solubility diagram, and the stoichiometric ratio of CBB(baicalin in CBB) : ${\beta}-CD$ complex is 1:1 and formation constant is 151 $M^-1$. The solubility, dissolution, in situ absorption and serum concentration of $CBB-{\beta}-CD$ were significantly increased when compared to CBB. Therefore enhanced bioavailability of CBB by inclusion complexation with ${\beta}-cyclodextrin$ might be useful for dosage form design of active ingredients of two herbal medicine.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.3 no.2
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• pp.121-135
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• 1999

This paper studies the problem of inverting minimal path sets to obtain minimal cut sets for complex system. We describe efficiency of inversion algorithm by the use of boolean algebra and we develop inclusion-exclusion algorithm and pivotal decomposition algorithm for reliability calculation of complex system. Several examples are illustrated and the computation speeds between the two algorithms are undertaken.

• Journal of Pharmaceutical Investigation
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• v.21 no.4
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• pp.223-230
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• 1991

The structural specificity and the chemical dynamics between ${\beta}-cyclodextrin$ and aspirin were studied by FT-IR UN, $^1H$ NMR. $^{13}C NMR$. and FAB-MS spectroscopy in solution and solid state, A stable solid inclusion complex was prepared by the recrystallization method, From the spectral changes of the host and guest molecules, orientational preference for binding in the cyclodextrin cavity was determined.

• Bulletin of the Korean Chemical Society
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• v.26 no.8
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• pp.1203-1208
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• 2005

A computational study based on molecular dynamics (MD) simulations was performed in order to explain the difference in aqueous solubilities of two flavonoid/$\beta$-cyclodextrin ($\beta$-CD) complexes, hesperetin/$\beta$-CD and naringenin/$\beta$-CD. The aqueous solubility of each flavonoid/$\beta$-CD complex could be characterized by complexwater interaction not by flavonoid-CD interaction. The radial distribution of water around each inclusion complex elucidated the difference of an experimentally observed solubility of each flavonoid/$\beta$-CD complex. The analyzed results suggested that a bulky hydrophobic moiety (-$OCH_3$) of B-ring of hesperetin nearby primary rim of $\beta$-CD was responsible for lower aqueous solubility of the hesperetin/$\beta$-CD complex.

• Journal of Pharmaceutical Investigation
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• v.23 no.1
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• pp.11-18
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• 1993

Inclusion complex of ibuprofen with $2-Hydroxypropyl-{\beta}-cyclodextrin\;(HP-{\beta}-CD)$ in aqueous solution and in the solid state was evaluated by the solubility method and the instrumental analysis such as infrared spectroscopy, thermal analysis and x-ray diffractometry. The aqueous solubility of ibuprofen was increased linearly with the increase in the concentration of $HP-{\beta}-CD$, showing an $A_L$ type phase solubility diagram. The results showed that the dissolution rate of ibuprofen was significantly increased by complexation with $HP-{\beta}-CD$. $Ibuprofen-HP-{\beta}-CD$ complex enhanced the mean plasma concentration levels and the area under plasma concentration-time curve after oral administration compared to those of the drug alone. It is concluded that the complex of ibuprofen with $HP-{\beta}-CD$ increases the dissolution rate and improves the bioavailability of the ibuprofen by the formation of a water-soluble complex.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.634-637
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• 2000

The productivity of natural flavors in alfalfa suspension cultures is low partially due to their low solubility. Thus, by formation inclusion complex of cyclodextrin(CD) with flavor compounds enhancement of the productivity of flavor was attempted in this research. we observed that CD formed inclusion complex with flavor compounds by GC/MS analysis. Also, there was indication that CD played a role as an elicitor in alfalfa suspension cultures.

• Journal of Pharmaceutical Investigation
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• v.13 no.1
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• pp.10-22
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• 1983

The interactions of ${\alpha}-cyclodextrin({\alpha}-CyD)$ and ${\beta}-cyclodextrin({\beta}-CyD)$ with several non-steroidal antiinflammatory drugs were studied on the effects of ${\alpha}-$ and ${\beta}-CyD$ on the solubility of the drugs in aqueous medium. Indoprofen, niflumic acid, alclofenac, and naproxen were chosen as representatives of antiinflammatory drugs. The solubility of all drugs studied increased with the addition of ${\beta}-CyD$, while not with glucose or ${\alpha}-CyD$. The increase of the solubility with ${\beta}-CyD$ was considered due mainly to the formation of inclusion complexes between ${\beta}-CyD$ and drugs. From the solubility data, the apparent stability constants K of the complex could be calculated. Ultraviolet absorption and circular dichroism confirmed the inclusion of indoprofen, niflumic acid and naproxen with ${\beta}-CyD$ in the molar ratio of 1 : 1. Inclusion complexes in solid powder form were obtained by the freeze-drying method and the inclusion formation was confirmed again by infrared, diffential thermal analysis, and X-ray diffraction measurements.

• YAKHAK HOEJI
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• v.38 no.1
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• pp.78-85
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• 1994

From phase solubility studies bile acids and bile salts were found to form stable inclusion complexes with ${\beta}-cyclodextrin$ in aqueous solution. Stability constant of bile acids were larger than that of bile salts. Phase solubility diagrams of most bile acids showed Higuchi's $A_I$ type but lithocholic acid showed $B_S$ type. Not only the solubility of bile acids but also that of ${\beta}-cyclodextrin$ increased, especially in cases of cholic acid and ursodeoxycholic acid. Solubility increase of bile acids from their ${\beta}-cyclodextrin$ inclusion complex followed the order : cholic acid>ursodeoxycholic acid>chenodeoxycholic acid>deoxycholic acid>lithocholic acid. It seems that solubility of inclusion complexes was directly related with the hydrophilicity of bile acids.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.7
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• pp.22-28
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• 1997

In this paper, We have studied internal quality incluiding chemical compositions, microscopic structure and nonmetalic inclusion of test material. We have analyzed dynamic characteristics of cutting resistence and compared chip treatment of the test material. In analyzing internal quality, all of the test material have typical ferrite+pearlite structure. But, nonmetallic inclusion has oxide and sulfide inclusion has oxide and sulfide inclusion in medium carbon steel, mainly sulfide inclusion is existed in S-free cutting steel. In Ca+S-free cutting steel, calcium aluminate and sulfide complex inclusion, had low-melting point, as deformation of sulfide and oxide inclusion is existed. Machining characteristics, cutting resistence is maximum in medium carbon steel. Chip treatement are excellent in S-free cutting steel, similar to the Ca+S free cutting steel and medium carbon steel.