Related Experiment Video
Updated: Mar 3, 2026

Coherent anti-Stokes Raman Scattering CARS Microscopy Visualizes Pharmaceutical Tablets During Dissolution
Published on: July 4, 2014
Superior Plasticity and Tabletability of Theophylline Monohydrate
Shao-Yu Chang1, Changquan Calvin Sun1
1Pharmaceutical Materials Science and Engineering Laboratory, Department of Pharmaceutics, College of Pharmacy, University of Minnesota , 9-127B Weaver-Densford Hall, 308 Harvard Street SE, Minneapolis, Minnesota 55455, United States.
Abstract:
A theophylline monohydrate (THm) powder, with particle size and shape substantially similar to a theophylline anhydrate powder, was prepared by vapor-mediated phase conversion. The elimination of possible contributions by particle size and shape to tableting properties made it possible to unambiguously identify the role of bonding area and bonding strength on powder tableting performance. It was also shown that accurate true density is essential for correct analysis and understanding of tableting behavior of THm. Experimental evidence revealed surprisingly high plasticity of THm. This is explained by its unique ladder-like structure, where rigid molecular dimers (rungs) weakly connect to more rigid water chains (rails). The low energy barrier for moving rigid dimers down the rigid water chains enables facile propagation of dislocations in THm crystals when subjected to an external stress.
Related Concept Videos
Pharmaceutical Alternatives: Polymorphic Form-Related and Particle Size-Related Therapeutic Nonequivalence
Antiasthma Drugs: Methylxanthines
Theophylline is thought to inhibit phosphodiesterase enzymes, increasing intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). This rise in cAMP and cGMP concentrations stimulates cardiac function,...
Factors Affecting Dissolution: Polymorphism, Amorphism and Pseudopolymorphism
Some polymorphic crystals possess lower aqueous solubility than their amorphous counterparts, leading to incomplete absorption. For instance, the oral suspension of Chloramphenicol, which...
Formulation and Manufacturing Process: Physical Attributes of Generic Tablets and Capsules
Factors Influencing Drug Absorption: Pharmaceutical Parameters
Factors Affecting Dissolution: Drug Permeability, Stability and Stereochemistry

