Jump to main content
Jump to site search

Issue 8, 2010
Previous Article Next Article

Understanding the relationship between crystal structure, plasticity and compaction behaviour of theophylline, methyl gallate, and their 1 : 1 co-crystal

Author affiliations

Abstract

Theophylline and methyl gallate can form a 1 : 1 co-crystal. Their tableting performance follows the order of theophylline > co-crystal ≫ methyl gallate. While co-crystallization profoundly improves the tabletability of methyl gallate, it significantly deteriorates that of theophylline. This difference in bulk compaction behaviour originates from the dissimilar crystal plasticity and elasticity, which results from unique molecular packing features in the respective crystal lattices. The presence of a three-dimensional hydrogen bonded network gives rise to very low plasticity in the methyl gallate crystal, which leads to its poor tabletability. In contrast, the layers of two-dimensional rigid, hydrogen bonded molecules in the co-crystal improve the crystal plasticity, by facilitating slip with shear that, in turn, enhances tabletability. However, theophylline undergoes plastic deformation more readily when compared to the co-crystal, because the slip layers in theophylline are composed of hydrogen bonded columns, which provide additional flexibility for slip. As a consequence, theophylline crystals have significantly enhanced tabletability.

Graphical abstract: Understanding the relationship between crystal structure, plasticity and compaction behaviour of theophylline, methyl gallate, and their 1 : 1 co-crystal

  • This article is part of the themed collection: New Talent
Back to tab navigation

Supplementary files

Article information


Submitted
13 Jan 2010
Accepted
21 Apr 2010
First published
18 May 2010

CrystEngComm, 2010,12, 2466-2472
Article type
Paper

Understanding the relationship between crystal structure, plasticity and compaction behaviour of theophylline, methyl gallate, and their 1 : 1 co-crystal

S. Chattoraj, L. Shi and C. C. Sun, CrystEngComm, 2010, 12, 2466
DOI: 10.1039/C000614A

Social activity

Search articles by author

Spotlight

Advertisements