Spheronization mechanism of pharmaceutical material crystals processed by extremely high shearing force using a...

Area of Science:

• Pharmaceutical Technology
• Materials Science
• Chemical Engineering

Background:

• Spheronization is a key process in pharmaceutical manufacturing for creating spherical crystals.
• Traditional spheronization often involves solvents, posing environmental and safety concerns.
• Mechanical processing offers a solvent-free alternative for crystal modification.

Purpose of the Study:

• To investigate the mechanism of solvent-free mechanical spheronization of pharmaceutical crystals.
• To examine the relationship between material characteristics and spheronization outcomes.
• To identify critical factors governing successful mechanical spheronization.

Main Methods:

• Utilizing a mechanical powder processor to apply extremely high shearing force to pharmaceutical crystals.
• Investigating the spheronization of theophylline, acetaminophen, clarithromycin, ascorbic acid, and lactose.
• Analyzing crystal fracture patterns, fragment size, and powder agglomeration.

Main Results:

• Theophylline and ascorbic acid formed core-shell spheres via partial fragmentation and layering.
• Acetaminophen yielded mosaic spheres through complete fragmentation and agglomeration.
• Clarithromycin and lactose failed to spheronize due to low cohesiveness and poor granulation.
• Material fracture strength influences intermediate fragment size, dictating the spheronization mechanism.

Conclusions:

• Material fracture strength is closely related to intermediate fragment size, determining the spheronization mechanism.
• Powder cohesiveness is a critical factor for successful mechanical spheronization, with moderate-to-high cohesiveness materials achieving spheronization.
• Solvent-free mechanical spheronization is feasible, but material properties like fracture strength and cohesiveness must be carefully considered.