|
Material Characteristic
|
Influences
|
Example
|
| Particle Size |
Bioavailability, Powder Flow, Compaction, Compression, Dissolution, Blend Uniformity, Protein Aggregation |
In a final crystallization step, particle size is a CQA (critical quality attribute) used to determine design space variables. Particle size distribution also has a direct impact on biologic material performance and processing. It can also be indicative of undesirable protein aggregation. |
| Particle Shape |
Bioavailability, Compaction, Critical Element in Solid and Liquid Dispersion Processing |
Product morphology in addition to size has direct influence on solubility. Inhaled products are based on less than 5 µm aerodynamic shape to be deposited in the lungs and not upper respiratory areas. Shape can be used as a PAT to define process send points and batch-to-batch variability. |
| Surface Area |
Dissolution, Solubility Compaction, Milling, Stability, Lyophilized Products |
It is apparent that the dissolution rate of a drug can be proportional to the surface area exposed to the dissolution medium. Surface area can provide critical information in lyophilization in regard to ice crystal formation. |
| Density |
Roller Compaction-Lubrication Tableting Setting, Segregation, Compaction, Crystallinity |
API and excipients are blended and typically then granulated or densified to ensure a uniform blend is delivered to the tablet press. The material is also granulated to aid in material movement as granulations move easier than powder blends. True density can be indicative of how close the material is to a crystalline state or the proportions of a binary mixture. |
| Porosity |
Roller Compaction, Tablet Shelf Life, Fragmentation, Compaction, Content Uniformity/Dissolution |
Indicator for shelf life and air and moisture penetration. Porosity measurement can evaluate the ability of liquids to penetrate the tablet for dissolution assessment. Can assist in parameter setting for material flow in coating operations. Predictive evaluation for pellet deformation during compression. Tablet crushing strength influenced by pore size distribution. |
| Inverse Gas Chromatography |
Powder Surface Energies, Acid/Base/PolarFunctionality of Surfaces, Diffusion Kinetics, Solubility Parameters, Phase Transition Temperatures |
Effect of manufacturing process (i.e. compaction, milling, and predictive particle interactions). Measure properties that help calculate Material Cohesivity and Hansen Solubility Parameters. |
|
|
|
|