کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8994329 | 1114390 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Nuclear magnetic resonance investigation of the interaction of water vapor with sildenafil citrate in the solid state
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم پزشکی و سلامت
داروسازی، سم شناسی و علوم دارویی
اکتشاف دارویی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Nuclear magnetic resonance investigation of the interaction of water vapor with sildenafil citrate in the solid state Nuclear magnetic resonance investigation of the interaction of water vapor with sildenafil citrate in the solid state](/preview/png/8994329.png)
چکیده انگلیسی
Solidâstate carbonâ13 (13C) and nitrogenâ15 (15N) nuclear magnetic resonance (NMR) have been used to investigate how water interacts with sildenafil citrate. When the humidity is altered, the water concentration in the solid compound changes in a reversible manner. The proportion of occupied sites depends on the humidity, but the water concentration never reaches a rational (e.g., 1:1) stoichiometric ratio to form a true hydrate. The NMR spectra were obtained under several humidityâcontrolled conditions to determine what changes occur as the water content is varied and where the water is located in the crystal structure. Only one set of 15N and 13C signals is observed for each humidity level. This shows that water incorporated into the crystal lattice of sildenafil citrate is very mobile and exchanges rapidly on the NMR time scale between various sites. The 13C data are consistent with formation of a hydrogen bond between a water molecule and one carbonyl of the citrate anion. The spectra also show that the water content affects the environment (perhaps influencing the average conformation) of the propyl group. Additionally, 15N dipolar dephasing experiments show that the sildenafil molecule is only protonated in the piperazine ring. The work is supported by solutionâstate NMR. © 2004 WileyâLiss, Inc. and the American Pharmacists Association J Pharm Sci 94:516-523, 2005
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Pharmaceutical Sciences - Volume 94, Issue 3, March 2005, Pages 516-523
Journal: Journal of Pharmaceutical Sciences - Volume 94, Issue 3, March 2005, Pages 516-523
نویسندگان
David C. Apperley, Pat A. Basford, Christopher I. Dallman, Robin K. Harris, Michael Kinns, Peter V. Marshall, Alistair G. Swanson,