著者

金庭 延慶

出版者

公益社団法人 日本薬学会

雑誌

ファルマシア (ISSN:00148601)

巻号頁・発行日

vol.15, no.10, pp.936-940, 1979

著者

金庭 延慶

出版者

東京大学

巻号頁・発行日

1959

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博士論文

著者

大塚 誠 松本 崇弘 金庭 延慶

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.34, no.4, pp.1784-1793, 1986-04-25 (Released:2008-03-31)

参考文献数

9

被引用文献数

70 95

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The effect of grinding in an agate centrifugal ball mill at 200 rpm on the physicochemical properties of indomethacin (IMC) polymorphs was studied by means of X-ray diffraction analysis, infrared spectroscopy and differential scanning calorimetry. The α and γ forms (metastable and stable forms) of IMC were ground at 4°C ant at 30±0.5°C, and the degree of crystallinity (Xc) of the ground products was measured by the X-ray diffractional internal standard method.The Xc of the γ form ground at 4°C decreased with increasing grinding time, and was 0% after 4 h, that is, the γ form had been converted to a noncrystalline solid. After grinding for 1 h at 30°C, about 45% of γ form of IMC was converted to noncrystalline solid, while the product ground for 10 h was transformed to the α form.The Xc of the α form ground for 2 h at 4°C was 0%, that is, the αform had been converted to a noncrystalline solid within 2 h at 4°C. The Xc of the α form ground at 30°C decreased with increasing grinding time and the value after 10 h was about 60%.The solubility in distilled water at 35°C of the γ form ground for 10 h at 4°C was about 60% larger than that of the intact γ form. The solubilities of the γ form gournd for 10 h at 30°C, the α form gound for 10 h at 4°C and the α form gound for 10 h at 30°C were all the same, 0.94 mg/100 ml, which is equal to that of the α form at 35°C.

著者

大塚 誠 金庭 延慶

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.32, no.3, pp.1071-1079, 1984-03-25 (Released:2008-03-31)

参考文献数

9

被引用文献数

35 43

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The effects of grinding on the physicochemical properties of cephalexin (CEX) were studied by means of water content measurements, differential thermal analysis (DTA), differential scanning calorimetry (DSC), X-ray diffraction analysis and scanning electron microscopy (SEM). The water content of CEX which had been ground for 4h and converted to a noncrystalline state was proportional to relative humidity (RH) in the range of 0-62% RH, and was about 2 mol/mol at 62-82% RH. The water content of intact crystal phase IV was about 1 mol/mol at 20-75% RH, and about 2 mol/mol at 82-95% RH. The X-ray diffraction data indicated that ground CEX remains in the noncrystalline state until it has absorbed more than about 2 mol of water per mol. At 62% RH, the water content of phase IV increased with increasing grinding time due to the conversion to noncrystalline state. The dehydration point of the ground CEX was depressed by up to about 25°C with increasing grinding time, and the decomposition point of the ground products was depressed by up to about 30°C. In general, the physicochemical properties changed rapidly when the crystallinity of the ground product fell below about 25%. The activation energy and mechanism of dehydration were determined by using nonisothermal kinetic analysis (Criado's method). The dehydration of the product ground for 4h (noncrystalline solid) followed first-order kinetics and its activation energy and latent heat were calculated to be 14.83 kcal/mol and 8.31 kcal/mol, respectively. The product ground for 4h was about 2.5 times more soluble than intact phase IV. The dehydration behavior and solubility of the product ground for 4h were different from those of the freeze-dried product, even though both products are in a noncrystalline state.

著者

金庭 延慶 大塚 誠

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.33, no.4, pp.1660-1668, 1985-04-25 (Released:2008-03-31)

参考文献数

7

被引用文献数

40 53

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The effect of grinding in an agate centrifugal ball mill on the transformations of polymorphs of chloramphenicol palmitate (CPP) were studied by means of X-ray diffraction analysis, infrared (IR) spectroscopy and differential scanning calorimetry (DSC). Three kinds of the polymorphs of CPP were reported, that is, forms A, B and C. There was no change in the X-ray diffraction profile of form A (stable form) on grinding for 600 min, but its profile became broader than that of intact form A. There was no change in the X-ray diffraction profile of form B (meta-stable form) on grinding for 130 min, but form B was transformed into form A by grinding for more than 140 min. Form B ground for 140 min contained about 35% form A ; when ground for 150 min, it contained about 80% form A, and when ground for more than 150 min, it contained a constant level of about 80% form A. The X-ray diffraction profile of form C (meta-stable form) suggested that form C was transformed into form B by grinding for 20 min ; thereafter the product was transformed into form A by grinding for 160 min. Form C ground for 4 min contained about 60% form B ; when ground for 20 min, it contained about 100% form B, and ground for 160 min, it contained about 80% form A. These results suggest that the transformations of polymorphs of CPP by grinding are form C→form B→form A. The melting point (mp) and the heat of fusion (H) were measured by DSC. The mp and the H of form A obtained by grinding were about 2.5°C and about 2.5 kcal/mol lower than those of intact form A, respectively, and the solubility in 50% (v/v) aqueous isopropyl alchohol was about twice that of intact form A.

著者

金庭 延慶 市川 順一 松本 崇弘

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.36, no.3, pp.1063-1073, 1988-03-25 (Released:2008-03-31)

参考文献数

12

被引用文献数

5 8

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Polymorphism of phenylbutazone was investigated in detail. Pure α form of phenylbutazone could not be obtained by conventional methods, but it was found that the β form was transformed to the stable α form in ethanol solution at 4°C. At 15 and 25°C, the β form was transformed to a mixture of the α and δ forms, while at 35°C, tha α form in the mixture was converted to the δ form. These results showed that the preparation of a pure polymorphic form by means of recrystallization in solution is not necessarily straightforward. The dissolution bethavior of each form in buffer solution was examined next. The transition temperatures of the pairs of α and δ forms and of α and β forms were 29.0 and 61.6°C, respectively, in buffer solution as determined by means of the non linear van't Hoff model proposed by Grant et al. The heats of fusion of the α, β and δ forms were 8.74, 6.48 and 6.85 kcal/mol, and their melting points were 91.2, 93.3 and 101.4°C, respectively. These results suggested that the pair of β and δ forms is in a monotropic relation and the pairs of a α and β forms and of α and β forms are in enantiotropic relationships.