کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2487685 | 1114428 | 2007 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Investigations on Solid-Solid Phase Transformation of 5-Methyl-2-[(4-Methyl-2-Nitrophenyl)Amino]-3- Thiophenecarbonitrile
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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: Investigations on Solid-Solid Phase Transformation of 5-Methyl-2-[(4-Methyl-2-Nitrophenyl)Amino]-3- Thiophenecarbonitrile Investigations on Solid-Solid Phase Transformation of 5-Methyl-2-[(4-Methyl-2-Nitrophenyl)Amino]-3- Thiophenecarbonitrile](/preview/png/2487685.png)
چکیده انگلیسی
Solid-solid transformation of 5-methyl-2-[(4-methyl-2-nitrophenyl)amino]-3-thiophenecarbonitrile from the dark-red to the red form was investigated. By controlled crystallization, the dark-red form was prepared and the crystals were sieved into fractions: coarse (>250 µm), medium (125-177 µm), and fine (<88 µm). The transformation rate order (fastest to slowest) of the different fractions is coarseâ>âmediumâ>âfine. However, milling accelerates the transformation, that is, smaller particles generated by milling transforms faster. Furthermore, ethanol vapor annealing slows both the transformation of the coarse and medium fractions, especially the latter. Therefore, the mechanism of transformation is not directly related to the crystal-size and most likely related to the amount and activity of the defects in the crystals. The three-dimensional (3-D) Avrami-Erofe'ev model, know as “random nucleation and growth” model, fits the kinetics of coarse fraction best. Higher relative humidity accelerates the transformation dramatically even though the compound is highly-hydrophobic. With minimal hydrogen bonding interaction involved, it appears even small amounts of water can serve as a nucleation catalyst by binding to the crystal surface, especially at defect sites, thus increasing the molecular mobility of these sites, promoting the transformation to the second phase and thereby increasing the transformation rate.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Pharmaceutical Sciences - Volume 96, Issue 5, May 2007, Pages 1079-1089
Journal: Journal of Pharmaceutical Sciences - Volume 96, Issue 5, May 2007, Pages 1079-1089
نویسندگان
Hui Li, Joseph G. Stowell, Xiaorong He, Kenneth R. Morris, Stephen R. Byrn,