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Updated: Aug 11, 2026

Microcrystallography of Protein Crystals and In Cellulo Diffraction
Published on: July 21, 2017
Anisotropic lattice contraction in pharmaceuticals: the influence of cryo-crystallography on calculated powder
1Eli Lilly and Company, Lilly Research Laboratories, Indianapolis, Indiana 46285, USA. gas@lilly.com
Abstract:
The following article examines the influence of thermal expansion on X-ray powder diffraction patterns. With the increasing percentages of structures that are being solved using low-temperature data sets and the nearly exclusive collection of room-temperature experimental datasets by X-ray powder diffraction, considerable discrepancies are observed when comparing calculated powder diffraction patterns to experimental patterns. Such comparisons are extremely valuable to solid-state pharmaceutical scientists attempting to identify crystal forms of active pharmaceutical ingredients and excipient components of formulations. In this study, fluoxetine HCl, raloxifene HCl, and olanzapine are examined and serve as practical laboratory examples. The observations are supported through analysis of data presented in the Cambridge Structural Database to help assess the extent and potential impact of this problem.
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