Related Experiment Video
Updated: Jun 10, 2026

Transport Properties of Ibuprofen Encapsulated in Cyclodextrin Nanosponge Hydrogels: A Proton HR-MAS NMR Spectroscopy Study
Published on: August 15, 2016
Anisotropic porous structure of pharmaceutical compacts evaluated by PGSTE-NMR in relation to mechanical property
Patrice Porion1, Virginie Busignies, Vincent Mazel
1Centre de Recherche sur la Matière Divisée-UMR 6619, CNRS and Université d'Orléans, 1 Bis Rue de la Férollerie, 45071 Orléans Cedex 2, France.
Purpose:
The pore space anisotropy of pharmaceutical compacts was evaluated in relation to the mechanical property anisotropy.
Methods:
The topology and the pore space anisotropy were characterized by PGSTE-NMR measurements. Parallelepipedical compacts of anhydrous calcium phosphate (aCP) and microcrystalline cellulose (MCC) were tested on top, bottom and side faces. A microindentation and three-point single beam tests were used to measure Brinell hardness, tensile strength and Young's modulus. All the data were submitted to a statistical analysis to test for significance.
Results:
The porous structure of MCC compacts was anisotropic, contrary to those of aCP. The analysis of the pore space by PGSTE-NMR method showed that its structural anisotropy was controlled by the behaviour under compaction of the excipients. At the same time, the Young's modulus and the tensile strength were the same whatever the direction of testing. For the aCP compacts, all the faces had the same Brinell hardness. With MCC compacts, only the bottom face showed a lower Brinell hardness.
Conclusions:
Except for Brinell hardness measured on MCC compacts, the tested samples were characterized by anisotropic mechanical properties when its porous structures were sometimes anisotropic. Then, there is not a straight link between porosity anisotropy and mechanical properties.
Related Concept Videos
Pharmaceutical Alternatives: Polymorphic Form-Related and Particle Size-Related Therapeutic Nonequivalence
Porosity in Cement Paste
The balance of water to cement in the mix is critical—it...
Formulation and Manufacturing Process: Physical Attributes of Generic Tablets and Capsules
Drug Dissolution: Requirements and Profile Comparison
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...
In Vitro Drug Dissolution: Compendial Testing Models I

