Powder X-ray diffraction study of polymorphic drugs: fluconazole and mebendazole

X-Ray Powder Diffraction Metrics

To compare sample data from x-ray diffraction a suitable metric is developed to evaluate the similarity (or dissimilarity) between samples and to compare it to a references. The methodology focuses on the d-lines and uses the intensity measurements indirectly in the algorithm. The resulting d-line distribution and summary statistics of the differences is used to establish whether a true differe...

Two-dimensional X-ray powder diffraction

X-ray powder diffraction on proteins

Macromolecular structures are traditionally determined by means of single crystal X ray diffraction from protein crystals of micrometer dimensions. Nevertheless, the growth of good quality single crystals can be very difficult or even impossible, especially in cases of large proteins, membrane proteins or protein complexes. Modern developments of X-ray powder diffraction have allowed the struct...

An accurate quantitative analysis of polymorphic content by chemometric X-ray powder diffraction.

Data from X-ray powder diffraction (XRD) were subjected to a partial least-squares regression analysis (PLS) to build a calibration model for predicting the polymorphic content of carbamazepine (CBZ). The effectiveness of the PLS method in the construction of calibration models was analyzed by a scientific approach based on a regulation vector. CBZ forms I and III were characterized by differen...

Identification of Polymorphic Forms of Active Pharmaceutical Ingredient in Low-Concentration Dry Powder Formulations by Synchrotron X-Ray Powder Diffraction

BACKGROUND The identification of different (pseudo) polymorphs of an active pharmaceutical ingredient in dry powder formulations is of importance during development and entire product lifecycle, e.g., quality control. Whereas determination of polymorphic differences of pure substances is rather easy, in dry powder formulations, it is generally difficult and the difficulties increase particularl...