著者

池田 浩人 森脇 英恵 松原 友規 湯川 美穂 岩瀬 由紀子 湯川 栄二 安藝 初美

出版者

公益社団法人 日本薬学会

雑誌

YAKUGAKU ZASSHI (ISSN:00316903)

巻号頁・発行日

vol.132, no.1, pp.145-153, 2012-01-01 (Released:2012-01-01)

参考文献数

8

被引用文献数

4 4

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The influence of the presence of a galloyl group in catechin on complexation with risperidone (RISP) was examined using (−)-epigallocatechin gallate (EGCg) and (−)-epigallocatechin (EGC), which are present in green tea as tea catechins. By quantitative analysis using HPLC, it was found that EGCg formed an insoluble complex with RISP for concentration dependence, whereas EGC did not. The large contribution of the galloyl group of catechin to form an insoluble complex with RISP was recognized in this study. In a molecular modeling study, it was found that the EGCg-R complex (EGCg with RISP) formed three hydrogen bonds between the hydroxyl groups of EGCg and the two N atoms and an O atom of RISP. The hydrogen bond between the hydroxyl group of the galloyl ring in EGCg and the N atom of the piperidine ring in RISP stabilized EGCg-R more energetically. The EGC-R complex (EGC with RISP) also formed three hydrogen bonds, but the N atom of the piperidine ring in RISP did not participate in hydrogen bond formation. According to the calculation using the COSMO-RS method, the water solubility of the EGCg-R complex was 1/26 that of the EGC-R complex. Therefore, the EGCg-R complex was difficult to dissolve in water. In the 1H-NMR spectra of RISP in DMSO-d6, although chemical shifts of protons near the N atom on the piperidine ring moved downfield on the addition of EGCg, no change in chemical shifts of these protons was observed on the addition of EGC. Therefore, based on these results, the galloyl group of EGCg contributes to the formation of an insoluble complex between tea catechin and RISP, and this insoluble complex is stabilized by the hydrogen bond between the hydroxyl group of the galloyl ring in EGCg and the N atom of the piperidine ring in RISP.

著者

末松 文博 湯川 栄二 峯本 正夫 湯川 美穂 大戸 茂弘 樋口 駿 後藤 良宣

出版者

一般社団法人日本医療薬学会

雑誌

医療薬学 (ISSN:1346342X)

巻号頁・発行日

vol.27, no.5, pp.426-431, 2001-10-10 (Released:2011-03-04)

参考文献数

18

被引用文献数

1 1

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The steady-state concentrations of digoxin at trough levels were studied to establish the role of infant characteristics in estimating the doses for digoxin based on routine therapeutic drug monitoring data. The data (n = 340) which showed a steady-state after repetitive oral administration in 147 hospitalized infants were analyzed using NONMEM, a computer program designed to analyze the pharmacokinetics in study populations by allowing for the pooling of data. An analysis of the pharmacokinetics of digoxin was accomplished using a simple steady-state pharmacokinetic model. The effects of a variety of developmental and demographic factors on the clearance of digoxin were investigated. Estimates generated using NONMEM indicated that the clearance of digoxin (L/hr/kg) was influenced by the demographic variables of age, the daily dose, serum creatinine, the presence or absence of congestive heart failure, and the coadministration of spironolactone in infants. The interindividual variability in the clearance of digoxin was modeled using proportional errors with an estimated coefficient of variation of 30.2%, while the residual variability was 28.2%.

著者

湯川 美穂 池田 浩人 萩原 里美 黒田 菜月 川原 光喜 湯川 栄二 安藝 初美

出版者

公益社団法人 高分子学会

雑誌

高分子論文集 (ISSN:03862186)

巻号頁・発行日

vol.72, no.10, pp.648-651, 2015-10-25 (Released:2015-10-23)

参考文献数

12

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The mechanical properties of moderately dilute solution of Konjac powder (KP) and its hydrolysates (hKP) were characterized by viscosity and texture profile analysis. hKP was prepared by partial acid hydrolysis of KP in 70% ethanol solution at 130°C. The viscosities of 0.3%~0.5% KP solutions and 0.6%~1.0% hKP solutions were about 50~500 mPa·s and 80~400 mPa·s respectively. The hKP solution moved around the mouth more slowly and allowed better control of swallowing than KP solution. This indicates that hKP may be useful as a thickener to take medicine due to its low adhesiveness.