title: Studying microstructure in molecular crystals with nanoindentation: intergrowth polymorphism in felodipine.
abstract: Intergrowth polymorphism refers to the existence of distinct structural domains within a single crystal of a compound. The phenomenon is exhibited by form II of the active pharmaceutical ingredient felodipine, and the associated microstructure is a significant feature of the compound's structural identity. Employing the technique of nanoindentation on form II reveals a bimodal mechanical response on specific single-crystal faces, demonstrating distinct properties for two polymorphic forms within the same crystal.
authors.affiliation: Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012 (India).
authors.forename: Manish Kumar
authors.initials: MK
authors.lastname: Mishra
authors.forename: Gautam R
authors.initials: GR
authors.lastname: Desiraju
authors.forename: Upadrasta
authors.initials: U
authors.lastname: Ramamurty
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Bond
mesh_terms: D000889:Anti-Arrhythmia Agents / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D015736:Felodipine / Q000737:chemistry*; D011110:Polymorphism, Genetic; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D000889:Anti-Arrhythmia Agents; D015736:Felodipine
keywords: X-ray diffraction; crystal engineering; microstructure; nanoindentation; polymorphism