Mechanical anisotropy and tabletability of famotidine polymorphs

Abstract

In the drug development process, early characterization of solid forms can help to envisage the bulk processability of a powder, which should assist in selecting an optimal solid form. In...

Recent Advances in Nanomechanical Measurements and Their Application for Pharmaceutical Crystals

“…Mechanical anisotropy, a material’s directional dependence property, of a crystal is an essential consideration for materials selection in pharmaceutical processing applications. ,, The investigation of anisotropic mechanical responses on multiple crystallographic faces of pharmaceutical crystals provides comprehensive information to estimate the formulation and performance in the early stage of drug development. ,,,, Nanoindentation has successfully been utilized to evaluate the mechanical anisotropy of crystal which offers a new perspective on supramolecular interactions that is intrinsic to the crystalline materials. Ramos and Bahr carried out nanoindentation on two faces, i.e., (100) and (001) of brittle sucrose crystals, and rationalized that H anisotropy was low for both the indented faces compared to the anisotropy in elastic modulus …”

Polytypism and Packing-Dependent Colossal Positive and Negative Thermal Expansion in a 2D Layered Cerium-Based Coordination Polymer

“…24−29 Much less attention is devoted to analogous phenomena among organic and metal−organic crystals, where weak intermolecular interactions may also give rise to the coexistence of different stacking motifs with comparable Gibbs free energies. A few examples of polytypism in such solids include some coordination polymers 30−32 and molecular compounds�L-tryptophan, 33 piracetam, 34 octadecanoic acid, 35,36 mononuclear rare-earth (RE) complexes, 37 and some others.…”

“…52 Furthermore, in general, CTEs are additionally packing-dependent. 34,53 Therefore, the studies of RE propionate polytypes and their thermal expansion represent significant interest.…”

Are Elastic Properties of Molecular Crystals within Reach of Density Functional Theory? Accuracy, Robustness, and Reproducibility of Current Approaches

“…Elastic moduli and anisotropy are interesting target properties for modeling studies because they can be derived from the elastic tensor, which is in turn an intrinsic quantity of a given single crystal structure. Indeed, single crystal elastic properties have been proposed to correlate with bulk properties of pharmaceutical compacts: Young’s moduli and anisotropies derived from nanoindentation, which has become a standard tool to obtain mechanical properties, have been found to correlate with tableting behavior of APIs. − In addition, elastic moduli are used in models of compaction . Elastic properties of a crystalline pharmaceutical compound could thus be used to classify its manufacturability, which in turn can inform process choices (e.g., direct compression versus granulation, addition of excipients), if available in sufficiently early stages of development.…”