Structure determination of diclofenac in a diclofenac-containing chitosan matrix using conventional X-ray powder diffraction data
Structure determination of diclofenac in a diclofenac-containing chitosan matrix using conventional X-ray powder diffraction data
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DOI：
10.1107/s0021889804002353
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发表时间：
2004-04-01
影响因子：
6.1
通讯作者：
Hannongbua, S
中科院分区：
文献类型：
--
作者：
Muangsin, N;Prajuabsook, M;Hannongbua, S
双氯芬酸嵌入在含双氯芬酸的壳聚糖矩阵使用常规的X-射线粉末衍射数据的结构测定证明。它表明，双氯芬酸钠，在制备含双氯芬酸的控释壳聚糖基质的起始材料，改变为双氯芬酸在空间群C2/c的矩阵。采用简单的方法处理样品，以获得足够高质量的X-射线粉末衍射数据，用于测定包埋在壳聚糖中的双氯芬酸的晶体结构。这些涉及研磨和通过微目筛筛分数次以获得合适的粒度和均匀的球形颗粒形状。采用传统的X射线粉末衍射数据结构解析方法。使用Le Bail方法提取X射线衍射强度。通过直接方法从提取的粉末数据中解析结构，并使用Rietveld方法进行精制。为了比较，还测定了同一药物的单晶结构。结果表明，由常规X射线粉末衍射数据解得的晶体结构与单晶结构符合较好。键长差和键角差的偏差分别为0.030埃和0.639度。
The structure determination of diclofenac embedded in a diclofenac-containing chitosan matrix using conventional X-ray powder diffraction data is demonstrated. It reveals that sodium diclofenac, the starting material in the preparation of a controlled-release diclofenac-containing chitosan matrix, changes to diclofenac acid in space group C2/c in the matrix. Simple methods were employed for handling the sample to obtain X-ray powder diffraction data of sufficiently high quality for the determination of the crystal structure of diclofenac embedded in chitosan. These involved grinding and sieving several times through a micro-mesh sieve to obtain a suitable particle size and a uniformly spherical particle shape. A traditional technique for structure solution from X-ray powder diffraction data was applied. The X-ray diffraction intensities were extracted using Le Bail's method. The structure was solved by direct methods from the extracted powder data and refined using the Rietveld method. For comparison, the single-crystal structure of the same drug was also determined. The result shows that the crystal structure solved from conventional X-ray powder diffraction data is in good agreement with that of the single crystal. The deviations of the differences in bond lengths and angles are of the order of 0.030 Angstrom and 0.639degrees, respectively.