Mechanical Properties of Carbamazepine and Its Cocrystals: A Multimodal Analysis Using Nanoindentation and Computational Structural Insights

Abstract

The mechanical behavior of molecular crystals is a rapidly emerging frontier, unlocking pathways to tailor properties for advanced applications and optimize manufacturing processes. Yet, decoding the intricate interplay between crystal structure and mechanical properties remains a challenge. This study offers a comprehensive, multidimensional investigation of carbamazepine (form III) and its cocrystals with succinic acid and glutaric acid, shedding light on how structural anisotropy dictates mechanical performance. Compared to carbamazepine form III, both cocrystals demonstrated superior fracture resistance attributed to the orientation of the slip/cleavage planes and interlocking molecular arrangements. Computational analyses, including reciprocal space mapping, attachment energy, intermolecular interaction energy, and interplanar spacing, enable a detailed description of cleavage planes and fracture directions.